Installing doors, especially interior doors, is not an extremely difficult task, but it involves a number of specific actions, thanks to which the door will function perfectly and look aesthetically pleasing. It often happens that when installing an interior door, ordinary or for a pencil case, an additional board is used. What it is and what it is intended for, we will consider in this article.

What it is?

The process of installing an interior door includes several stages:

  • collecting a box or frame in which the door will function;
  • setting and securing the box in the doorway;
  • preparation of the door leaf, installation of fittings;
  • installation of the canvas in the box, fitting and adjustment;
  • finishing with platbands of the doorway.

Dobornik on interior doors – this is a decorative element that expands the box if it does not match the width of the opening. It seems to continue the door frame, creating a single and integral structure. Essentially, it is a 90-degree slope made of rectangular slats and a casing made of solid materials.

What do they look like?

The slats have a wide range of color options. In the vast majority of cases, they are made from the same material as the door frame with the door. Therefore, it is more profitable to purchase doborniki together with a door and a frame from one manufacturer or company. When assembled, the dobors have a U-shape.

Cloths of extensions made of wood-based materials can be with a protective edge, or their ends remain untreated. Also, a groove can be made on the edge on one side, and a spike on the other. Such extensions are a type of lining. Telescopic boxes are completed with such extensions.

Why are they needed?

Add-ons for interior doors hide all the defects of the opening, protect against mechanical influences, serve as an additional reinforcement of the frame, as well as an important decoration of the door.

The standard dimensions of the width of the door frame are 80 cm and 100 cm. If the width of the doorway is greater than these dimensions, then during installation there is free space that needs to be ennobled. You can, of course, order a box of any width that matches the dimensions of the doorway, but custom work increases the cost of the purchased product by several times compared to a standard order. And even more so when the door is made of a rare breed of wood.

It is precisely for this to close this free space and save on material, and you need such an element as extensions. They serve to create your own design, give you the opportunity to realize your imagination by choosing material, color, style and shape.

The aesthetics of the entire interior depends on a carefully made door slope.

What are the types?

Types of extensions differ in the way they are installed:

  • attached;
  • lining;
  • combined;
  • telescopic.

You can attach them to the door frame both before installation and after, when the jamb is securely installed. For fastening before installation, either small self-tapping screws or glue are used.

You can fasten the box with the dobor using thin metal plates. For example, pieces of "crocodiles" (fasteners for attaching guides) used to mount the frame under drywall.

Ways to collect extras on the box before its installation:

  • To begin with, we assemble the box, sawing the guides at 90 or 45 degrees, 6 mm more than the width of the door leaf, for a working gap of 3 mm along the perimeter of the leaf. If there is no quarter-shaped groove on the guides on the back, it must first be made on a circular machine or with a cutter. Using a chisel for this job is time-consuming and requires professionalism to achieve the desired quality. The width of the quarter is chosen corresponding to the width of the extension, and the depth is about a centimeter.
  • We cut off the selected extension to the width necessary to block the opening together with the box. Cut along the length of the vertical and horizontal strips so that the horizontal piece overlaps the vertical ones.
  • We make formwork along the perimeter from the wrong side of the box from an even material, for example, from drywall. Why do we fasten its strips about the size of the width of the prepared extension with self-tapping screws to the box.
  • Align the vertical parts of the door frame with respect to the floor at an angle of 90 degrees.
  • We apply glue (any for wood or liquid nails) into the groove, insert the extension, adjust it so that there are no gaps. From above, for the fortress, you can tighten the parts of the extension with self-tapping screws, be sure to drill holes with a thin drill for the entire length of the self-tapping screw so that the canvas does not swell or crack. Then we leave to dry. As soon as it dries, the formwork is removed and the jamb is mounted.

Can be done without glue. Planks are prepared in the same way. On the back side of the box, where the quarter is located, plates are screwed, extensions are inserted and fastened with short self-tapping screws.

If there is no groove, you can cut panels from the selected material with a width corresponding to the width of the opening to be covered. Assemble a box from the extensions, and insert the door jamb inside. This can only be done if the extension is thin, or if the distance for mounting the whole assembly allows, and the trim is wide enough to cover the mounting seam.

Methods for installing extensions on a mounted box are used when there is an already installed jamb with a door, and the box has a quarter for extension.

Method one:

  • This area is freed from foam and thoroughly cleaned.
  • Using a tape measure and a corner, measure the distance from the recess in a quarter to the end of the opening, in several places around the entire perimeter.
  • Cut to length and width of workpiece. They are inserted into the groove, and in this place the extensions are supported in several places to the box, for example, with a bicycle thermometer or pieces of hardened foam, polystyrene. After that, they are wedged so that there are no gaps and the extensions stand at 90 degrees relative to the plane of the door.
  • Construction foam is applied only to the part that is at the point of contact. After the foam hardens, you can process the entire slope with it. It is better to use foam with a small coefficient of expansion for mounting. If there is no groove, then the dobor cloth is slipped under the box, wedged and foamed.

The second method, which is used if it is not possible to put the extension on the foam, and the thickness of the extension allows you to drill through it:

  • We make several holes in the dobor bar. Three holes are enough in the horizontal bar, and four holes in the vertical bar. In the place of the holes, with a drill of a larger diameter, we make indentations to drown the heads of the self-tapping screws.
  • Using a tape measure and a corner, we measure the distance from the box to the edge of the opening. According to the largest size, cut off the width of the extension. A prerequisite: the dimensions at the junction of one plank with another, that is, in the corners, must be the same.
  • We cut out small even rectangular bars from the material at hand and slip them under the box in the places of fasteners. We drive self-tapping screws into the planks, apply them to the box, press them against the bars and pull them with a screwdriver, making sure that there are no gaps at the joints. This can be done if the width of the extension is not more than 20 cm. In the same way, you can assemble the box before installing it.

Method three:

  • A thin rail, like a glazing bead, is nailed onto the box, no larger than 10/10 mm in size around the entire perimeter. If there is no rail, then at a distance of about 5 mm from the inner edge of the box, self-tapping screws are screwed around the perimeter or nails are driven in. The hats are cut off with a grinder, leaving the pins about a centimeter.
  • The extensions are prepared in the above way, wedged and more spacers are added between the side extensions in the place where the nails were nailed and from the floor to the horizontal extension. It is better to fix the extensions with masking tape from one wall to another through the opening. And in the same way they foam.

The fourth method is the crate of an open opening:

  • For this, blocks are prepared no thicker than the gap between the opening and the box, or a little thicker, but in this case, a line is drawn around the entire perimeter of the box at the same distance for a guide. Any length, as long as it does not crack during installation. Width from the box to the edge of the opening.
  • They are mounted on dowels to concrete and brick, using a building level and a corner. Dobors are prepared in the same way. Attach to the bars on liquid nails. After drying, you can foam for soundproofing.

Method five:

  • It is possible to fasten the extensions directly to the opening with liquid nails, if they cover the mounting seam with their thickness. To do this, glue is applied pointwise to the opening. They take a bar a meter and a half, apply it to the slope and use a mallet to level the plane. Secure with masking tape until dry.
  • Clamps can be used to secure the extensions to the box. To do this, prepare extensions in length and width, assemble a box from them, apply liquid nails to the end, apply to the jamb and tighten with clamps until dry.

Telescopic

This type of extensions is assembled as a constructor. It is advisable to use a cutting milling machine in your work. Without it, it is quite difficult to make cuts at 45 degrees using a simple miter box for this. Therefore, when assembling the box at 90 degrees, it is necessary to ensure that the groove for the addition at the junction is solid. Dobors are inserted into it, having a spike on one side, and on the other, a groove into which the casing is inserted.

The depth of the groove is 15 mm, which makes it possible to "walk" in size in width when purchasing or adjusting the additional and cashing. The steps for measuring, cutting and fastening are the same as for straight planks.

Their convenience lies in the fact that they are easily assembled together, and make it possible to cover any distance.

Combined

Combined types of doborniks are corner strips made of fiberboard, MDF, PVC - they are both an addition and a cashing out. Use this type of additional slats with insufficient overlap distance. Attached mainly to liquid nails.

Dimensions

Standard sizes of extensions on the market:

  • thickness 6-30 mm;
  • width 50 -250 mm;
  • length 2100 mm.

Width of telescopic panels 90, 120, 150 mm. A quarter on the box for addition is most often 10/10 mm, so the thickness of the bar is 1 cm.

The required plank width is the width of the opening minus the width of the door frame, plus a quarter, if any. Additional boards can be prepared by hand. Such an item of non-standard sizes can be made to order.

When installing door frames, it often becomes necessary to close the rest of the slope with something. Most often, for these purposes, "additions" are used, which can be purchased together with door panels and platbands. However, in most cases, such additional elements require adjustment, since the extension should be attached to the box as tightly as possible, and always strictly according to the size of the visible part of the slope.

door frames

There are two options for door frames, to which extensions are usually attached:

  • with a groove for him,
  • without groove.

In the first case, the additional element is inserted into the groove of the box with one (long) side, while its second side is loose.

In the second option, the extension will need to be attached to the slope, without fixing to the door frame.

Choice of extensions

Dobors are planks made of laminated MDF. The color of these elements usually matches the color of the door frame and trim. But if you wish, you can always purchase extensions of a different color, if this option is more suitable for the design of your room.

Do not forget that the extensions cover the slopes from three sides - from above and from two sides. In this case, it is desirable that the upper extension be longer than the width of the door, and the vertical extensions rest against it at a right angle.

A variety of width extensions allows you to choose them for slopes of almost any width. The main thing is that the additional element does not turn out to be narrower than necessary. If it is not possible to choose an extension exactly in size, it can be cut. To do this, it is recommended to contact furniture workshops, since in addition you should also order an edge tape sticker on one or two ends of the extension.

Groove extension installation

First, consider how to attach extensions to the door if the door frame has a special groove:

  1. Install and secure the door frame in the opening. You can even hang a door - this will not affect the installation of extensions.
  2. Cut the extensions to length to the required size.
  3. Measure the distance from the outer edge of the wall (slope side) to the door frame in at least three places. If these distances do not match, then the extension will have to be cut in a furniture workshop. On the end of the dobor, to which the platband will be attached, it is also necessary to stick the edge tape there.
  4. Insert the extensions into the grooves of the door frame: first the top horizontal, then the side vertical ones. Dobors should be located strictly at an angle of 90 degrees to the plane of the door frame.
  5. Check if they are horizontal or vertical.
  6. Stick masking tape in 4-5 places along the length of the extension in such a way as to fix it in the desired position with it.
  7. Fill in mounting foam the space between the wall and the extension.
  8. Wait for the foam to harden, cut off the excess that has come out.
  9. Attach trims.

Installation of extensions without a groove

After installing the door in the doorway, it is necessary to measure the remaining unclosed part of the wall (slopes). If the extensions have to be cut along the long side, then it is better to do this also in a furniture workshop. In the same place, order an edge tape sticker from two ends of the extensions (both from the side adjacent to the door frame and from the side of the trim).

If the slopes are not plastered, then the extension should be fixed as follows: take a wooden plank or a small bar and attach it to the slopes in such a way that the extension can be fixed on top of this bar, while maintaining its verticality (horizontal - for the upper extension) and right angle between it and the door frame.

With smooth plastered slopes, you can do without an additional wooden plank, provided that there is no need to leave any space between the extension and the wall.

  1. Attach an extension to the bar.
  2. Fill the remaining space between the wall and the extension with mounting foam. To make the foam harden faster, sprinkle it with water.
  3. Cut off excess cured foam.
  4. Fasten the platbands.

Benefits of using extensions

As you can see, the technology of fixing the extensions allows you to avoid such a tedious procedure as plastering slopes. A properly selected additional element makes the slope smooth and beautiful, no matter how bad the slope looked before. However, if the space between the extension and the wall exceeds 3-4 centimeters, it is better to additionally fix the extension with small wooden bars screwed to the wall.

In cases where you do not have the opportunity to use factory extensions, you can make their man-made "analogue" from laminate or MDF panels. This solution will allow you to perform "divergent" slopes (located not at an angle of 90 degrees relative to the door frame).

Video

Useful installation instructions:

Below you can see how the extensions are installed:

06.04.2014 07:00

When buying interior doors, we come across phrases: "if you need to install extras, then..." , Will you need extras?"... and so on. So what is dobor or dobor? I'll try to explain in detail:

What are the extras?

The dobor is a "board" a little more than 2 meters long (207-215 cm), usually 10 mm thick, which is finished on one side in the same color as our door. But the dimensions in width, depending on the model of the door, come in different standards, the most common sizes for the width of the extensions are: 10 cm, 12 cm and 15 cm, less often - 20 cm, there are extensions even 40 cm wide. If you need even wider extensions, then this is already on order. I don't see the point in making them even wider than 20cm, since you can always make a compound extension (combine them), which is much easier than installing an extension 40cm wide.

So why do you need extras?

In order to gain (increase) the width of the door frame, the width of which is less than the thickness of the wall of the doorway. For example, the thickness of the wall in the opening where we want to install the door is 17 cm, and the width of the door frame is 7 cm, it follows that we need to add 17-7 = 10 cm with an extension. We also take into account the fact that the extension board is usually inserted 1 cm inside (in the groove on the back of the box). So we need extensions 11 cm wide. We look at the existing standards and, if there are 12 cm, then we take 2.5 sticks (additional boards) for this opening. The door installer will cut off the extra centimeter. If there is no 12, but there is 15 cm, then we take them.

Another example: The wall thickness of the doorway is 8 cm at the bottom and 7-7.5 cm at the top. What should I do? It turns out that we need an addition (according to the maximum width we consider) 8 -7 +1 = 2 cm? Are there such benefits? You are unlikely to find such a wide extension, the answer is simple - for 1 opening we will need 1.5 extension boards 10 cm wide (that is, the installer will dissolve 1 extension into two, and insert the cut side of the extension into the groove of the box). The given examples of calculating extras are suitable for extras standard type , whose platbands are not telescopic. If you have telescopic architraves (look from the end G- figurative), that is, the platbands are inserted with their protruding spike into the groove of the box and thereby allow to push somewhere a little more, and somewhere less in the range 0-1.5 cm. So, using telescopic casing, we will do without extensions for openings with a wall thickness of up to 9 cm for the majority of door types, as well as for doors Dors profile , despite the fact that there is a spike on the trim for these doors 2 cm That is, if your wall thickness varies from 8.5 to 10 cm, then here you will need an add-on! An experienced craftsman will cut the groove shelf on the door frame in a circle and fix the sawn extension on self-tapping screws or studs. This is a difficult moment in the work, and not a single door manufacturer will show you this method of fastening the extension. Use!))

Generally about telescopic architraves I want to say a lot more. Indeed, a monument to that inventor should be erected. After all, the advantage of telescopes is not only that we save on extensions, judging by the examples above, but we also win very much in the aesthetic design of the door, with uneven walls of the opening! In order for your door to close tightly (correctly), the left and right walls of the doorway must be in the same plane, and not a propeller! In reality, this rarely happens, especially if the repair of the walls was not according to the lighthouses. So this is where telescopic architraves really help us! That is, we can drown the door frame a little (up to 1cm) inside the opening, and where necessary - push it flush with the wall, thereby still adjusting the door plumb. So, apart from the pluses, I don’t find any minuses in using telescopic architraves.

In our store, interior doors with telescopic architraves You can choose from the following categories:

How much does it cost to install extensions?

Installation of extensions comes as an additional service - a subtle and significant "nuance", which, as a rule, the client learns about during the installation process, which is later disappointed, since the final amount of door installation is already different from the original one! That's why you shouldn't go for low price door installation. The cost of installing extensions on an interior door, as a rule, will depend on the width of the extension. Some firms increase the cost of installing extensions for every 5 cm width!

Why are we better?

  • When ordering doors and their installation from us, we will take into account all your wishes and, after measuring, we will calculate the number of extensions so that after installation there is no excess left, which means you do not have to overpay
  • Installation of a door with or without extension costs the same for us.
  • The price for installation is negotiated during the measurement and subsequently does not change, even if we did not take into account something.
  • Our reputation is important to us, so guarantee for the installation of interior doors, we give 3 years!

And here is how the extensions look on the example of our work:

The table will help you choose the right number of extensions for the thickness of the walls of the doorways .

Doorway wall thickness (cm) Finishing board (pcs.)
single leaf door double door
10cm 12cm 15cm 20cm 10cm 12cm 15cm 20cm
5 - 7 cm - - - - - - - -
7.5 - 11 cm 1.5 pcs. 2 pcs.
11.5 - 12 cm - 1.5pcs - 3 pcs.
12.5 - 16 cm 2.5pcs 3 pcs.
16.5 - 21 cm 2.5pcs - - 3 pcs.
from 21.5 - 26.5 cm - - - 2.5pcs - - - 3 pcs.

If you have any questions -

The catalog page of the OBI hypermarket contains accessories for interior doors. Here you can buy individual trims and other accessories worth from 50 to 4500 rubles. There are about 300 items in this category in stock.

When buying components from this section, you must accurately select:

  • . Product color and texture.
  • . Height, width and thickness dimensions.
  • . Front surface finish.

Door frames are designed for installation along the perimeter in an opening of standard sizes. They are a product prepared for installation, sold complete with fittings and fasteners.

Platbands are used for decorative framing of the opening. Behind them hide the space (slits) between the canvas and the wall. Dobors are installed to expand the door structure and the original decoration of the walls. Manufacturers make these decorative elements in the same color schemes, as the canvases of all the main series.

Order in the OBI store accessories for installing interior doors with manufacturer's warranties.

Payment and delivery methods

  1. Purchase goods online with delivery
  • . You can pay for the order in cash or by bank transfer.
  • . You will coordinate the date and time of delivery with the operator by phone when confirming the order.
  • . The terms of the free service depend on the city, amount and weight of the product.
  • . Unloading goods, lifting and carrying are additional services and can be paid separately, check with the store operator.

Detailed information about the intervals and zones by city, the conditions for unloading and lifting the order are located, where you can independently calculate the cost of your delivery in advance, indicating the postal address and parameters for unloading.

  1. Order and collect yourself where it is convenient for you
  • . When filling out the order form, indicate a convenient date and time for you to visit the hypermarket.
  • . You can pay for the purchase in cash or by bank transfer at the cash desks of the store.

Purchased goods can be picked up at any of the OBI stores in Moscow, St. Petersburg, Ryazan, Volgograd, Nizhny Novgorod, Saratov, Kazan, Yekaterinburg, Omsk, Krasnodar, Surgut, Bryansk, Tula and Volzhsky.

Mostly all doors that are manufactured in specialized factories are designed for a certain wall thickness. It is in many cases of the order of 70 or 80 mm. But what about the owners of country or ordinary private houses? Their walls are often much thicker than apartment options.

In this case, you can finish the opening with sheets of drywall or do it even easier - apply the installation of an extension to interior doors. The method is simple and requires much less time and effort to implement. Some homeowners plaster openings in places where there is no box. But, nevertheless, the method of installing extensions is less time-consuming and more effective. Therefore, you need to carefully figure out how to fix the extension correctly.

What are add-ons?

Dobors are two racks located in a vertical position, and one horizontal bar. It is located at the top of the opening. Thus, the finished design increases the box itself. Among the commonly used materials for the manufacture of structures, the most popular are fiberboard, solid wood and MDF. They are durable and affordable in their price range.

Measurement and preparatory work

The installation of extensions is necessary first of all in order to securely fix the platbands. It is possible to make the correct fixation of the platbands if the products are placed end-to-end to the plane of the wall. It is best to take measurements with the box assembled and installed. After that, the installation of extensions is already carried out.

Initially, you should put ruler on the platform of the box and keep it strictly perpendicular to the wall. It is necessary to determine the dimensions of the upper and lower parts of the product. At the same time, the width of one extension in different parts may differ, since the walls are almost always imperfect. All data should be entered on paper so as not to confuse the parameters of the product.

Many experienced professionals use a more accurate method. Measurement of all additions is made by means of square and flat rail. The first fixture is installed in the seat, and the second is applied to the plane of the wall. Where the square intersects with the rail and there will be a width indicator. The size of each slope must be carefully checked, since an error can be made at any stage.

After the manipulations, proceed to cut the board. This is easy to do with a hand saw. A jigsaw and a stationary machine are also well suited, provided they are available.

Installation

Installing dobors on the interior door with your own hands is quite simple. To do this, you need to decide, first of all, with the type of box. They are:

The first option is the easiest. It has everything to safely carry out the installation of extensions. The versatility of the presence of the groove is that it allows you to adjust the position of the extension. And also this device saves a lot of time. By adjusting the bar, it can be immediately fixed to the wall.

Self-tapping installation

The first thing to do is to drill a hole under the self-tapping screw. As a rule, MDF boards, from which blanks are most often made, are approximately 10 mm in thickness. This means that the drill must have a maximum diameter of 9 mm. In order to more accurately and reliably mount extensions on the interior door, the diameters of the drill and the heads of the screws must match.

Directly, the screws are chosen so long that they literally go a little into the canvas of the box. If the products are too long, the wood will crack. A prerequisite is the use of wood drills. They are characterized by the presence of special protrusions in the form of needles. Such products are capable of accurately centering holes.

When the tool is selected, we drill a hole for the self-tapping screw. In this case, you need to choose not a perpendicular direction, but set the drill at an angle. This method will allow you to fix an additional element to the central part of the door frame.

The vertical racks are screwed first with self-tapping screws. After fixing them, proceed to the installation of a horizontal bar.

Installation on carnations

Another very effective way door trim installation is a method of applying studs.

For installation, you will need to drill small holes into which finishing nails will then be hammered.

Critically important - the drilled holes must be less than the length of the nails!

After that, it is necessary to insert the carnations with the sharp side outward, and remove the hats with wire cutters. A mounting bar is often used for driving nails.

When all the fasteners are in place, you can put extensions and gently nail the product, connecting it to the box.

Foam installation

Installing door extensions according to this principle is several times faster than other methods. Products are put in place. After that, they need to be wedged from the inside. Surfaces should be pressed against the door frame. It is possible to fix the opening only after thorough cleaning and mandatory wetting of the surface.

Installation of telescopic extensions

This type of product has its own unique advantages.

  • It can be tightly fixed in the overall structure.
  • The surfaces are securely attached to each other.
  • Connecting the components together is quite simple.
  • Dobory with this configuration can be shifted either up or down.
  • It is possible to move them inside and outside the product.
  • The power reserve of the parts is small, but these millimeters allow you to adjust the position of the extensions as accurately as possible and correct the mistakes that were made during the marking.
  • Special "adjustment" grooves make the design convenient and easy to install.

Along with the box

The method is to assemble the entire structure before attaching it to the wall. Both the box and the dobors are assembled into one. Additional elements that expand the opening are attached to the door frame. After that, the finished product is fixed.

The following tips will be helpful:

  • Carnations are used solely to press additional panels to the door frame. They do not keep from shifting.
  • In the process of drilling holes, a crack can be made on the front side of the product and between the slopes. Therefore, all work must be done carefully.

Doborny board (dobor) for the door frame: purpose, types, installation

If you put a door frame and it is smaller in width than the thickness of the wall, this gap must be closed with something. To do this, use the extensions on the interior door. About what they are, how they look, what they are, how to put them, and we will talk further.

What is dobor

When installing interior doors, a situation arises when the box is less wide than the thickness of the wall. In such cases, a special board is used, which is attached to the door frame, closing the remaining space. This board is called the addition to the interior door. There is also the name "additional board" and "additional plank". Then you can attach a casing to it, which will close the gap between the extension and the wall.

Dobor - a board for expanding the door frame to the thickness of the wall

That is, the door dobor is an additional part of the door frame. It is a board of certain sizes, which is joined to the door frame. They put it on one side - opposite to the one into which the door opens. You can also call this board an expander - it displays its real purpose.

If the wall thickness is more than 140 mm, you have to install a door frame expander - an additional board

There may be nuances in the docking of the dobor. Often the shape of the door frame is specific - with a special relief (protrusions, depressions, roundings). Then you will have to look for an extension of this particular company, otherwise it will be problematic to dock them.

Materials and dimensions

Each of the manufacturers produces a certain set of additional boards, in which the length is fixed - 230-250 cm, the thickness / width changes. For example, there are such options (thickness, width, length):

Shape, thickness, width may vary

Thickness and width - each factory has its own. Can be 60 mm, and 65 mm or 75 mm. In general - any set. What if none of them is suitable for your case? Take a larger width than required, then saw off the excess. And if your opening is wider than all available options? Order the right size (many manufacturers make to order) or splice two smaller sizes. Another option is to use telescopic architraves. They come with a fold around the corner, which can cover your lack of width.

If the doors are made of solid oak, it makes sense to put the same extension

What materials are used for interior doors? From the same as the platbands:

  • wood;

MDF and chipboard can be veneered, laminated. Wooden ones can be with or without processing. Match the material and color to the door frame. And this is another reason to buy from the same manufacturer - even if the name of the color / texture is the same, there is no guarantee that they will actually be the same.

Types of extensions

There are two types of doborny board:

  • With straight edges. An ordinary board, which is attached end-to-end with a box. May be:
    • with decorative edge;
    • without decorative edge.

    Types of extensions for interior doors: telescopic on the left, ordinary - on the right

    Dobor on an interior door with straight edges - the most common board. In this case, it must be selected only by color and size. The dobor is pressed against the box, fixed with screws installed obliquely. One of the ends of the additional plank can be processed. This is necessary if the clypeus can be displaced.

    Installing an extension with smooth edges (not telescopic)

    It is not very convenient to mount this type of extensions. You have to think about how not to split the bar, about how to close the caps of the screws. However, it is not necessary to select according to the shape of the grooves / protrusions, which is far from simple and binds only to one manufacturer.

    If there are protrusions, grooves, roundings, you need an extension for an interior door of the same company as the box

    The telescopic door extension has pre-formed grooves. From the point of view of docking, this is a very convenient option: they drove the protrusion into the groove, tapped until it completely coincided and the whole installation. But only if the match is perfect. What else is a telescopic extension convenient for? A telescopic casing can be installed in it (if it fits).

    How to install extensions on an interior door

    In this paragraph, we will focus on ordinary slats - with straight ends. They are sold in lengths of 2100-2300 mm. Three strips are needed for one door: One on the right and one on the left, and a piece from the third will go to the top. If you put several doors at the same time and you have them of the same color, one plank will go to the two “tops”.

    How to fix extensions on an interior door

    Planks are usually wider and longer than necessary, so they will have to be trimmed. What tool? With what you have. A juvenile who cuts DMF, chipboard or wood is suitable. To decorate the corners, you may need a miter box (if you are going to join the box (and extensions) at 45 °. It is also convenient to use it to “not fill up” the cut and make it strictly perpendicular.

    We take measurements and make blanks

    Before installing extensions on an interior door, you need to find out the exact dimensions of the expansion bars. To do this, we install a door frame in the doorway, fix it. Draw an opening on the plan, it will be easier to write the dimensions. Next, take a tape measure and a level, measure the size of the extensions that you need.

      The width of the extension is determined as follows: we insert the measuring tape of the tape measure into the groove until it stops. We apply a level to the wall, at the intersection with the roulette tape we determine the required width. Measurements are carried out at six points: two on each side. If the wall has an unequal thickness, we take the width of the extension according to the largest figure.

    Now, in size, we cut out those that we need from standard planks. Make marks with a pencil - on light strips a simple pencil is clearly visible, on dark ones you can take a white one. We try on the cut-out strips in the opening, if necessary, cut them a little.

    Collecting

    Before you put the extensions on the interior door, they must be connected to each other. We lay out the cut-out additional strips on the floor in the form of the letter "P". If they have a finished edge, lay them out so that the edge is on one side. Planks will need to be connected to each other. If they are made of MDF or chipboard, you must pre-drill holes in the top bar.

    Assembly preparation

    To do this, it is better to take a square (ideally, a carpenter's square, but an ordinary school one will do). On the bar we draw a line that marks the middle of the thickness of the bar. If the board thickness is 10 mm, the line runs 5 mm from the edge. If the bar is 15 mm thick - at a distance of 7.5 mm. We put two points on this line, and then we drill holes. Diameter - 1 mm less than the diameter of the screws.

    We complete the assembly of the dobor in the door frame

    Next, the holes must be transferred to long strips. To do this, we join them, align the edges. Using a drill, we transfer the marks to the end of the bar, then deepen it to the required length (along the length of the self-tapping screw). Having made holes, we join the strips, we twist the fasteners. The addition to the interior door is half assembled. But do not rush to attach the second bar. It is necessary to try on the already assembled “in place”.

    Fitting and trimming

    We put the assembled L-shaped part in place, driving the planks into the groove in the door frame. The upper jumper turned out to be larger (we measured it this way). We take a pencil, put a mark where the groove begins. Try to be precise as this is important. The excess can not be cut off. Just draw a line along the mark and make marks on it, then drill holes. After assembly, the letter "P" is obtained. We have assembled the trim for the interior door, now we need to install and fix it.

    Door frame installation

    Now the plugin can be installed. Check opening first. If the doors were placed on the foam, it can block the groove. We cut off the excess so that the slats go in freely. We insert the U-shaped structure into the groove, tapping the butt with the palm of your hand. We start at the top, then on the sides.

    We put in place, after removing the excess mounting foam

    We take masking tape, we fix the strips to the walls with it. If in some places the extension to the interior door does not fit snugly against the box (there is a gap), we remove this gap with the help of linings. To do this, you can use mounting wedges. If they are not, make from foam. You just need to set the bar evenly, for this purpose dense foam is enough.

    Attachment box

    It is also necessary to align the addition to the interior door to the level. You should not focus "by eye", use the level. Using a level and wedges, we remove all protrusions and blockages. In the process, we fix the aligned areas with masking tape. The distance between the tacks is 40-50 cm. One at the top and bottom (receding about 10 cm), and further at regular intervals.

    How to attach extensions: in the process of installation

    Next, using low expansion mounting foam, fill it with the space between the wall and the additional plank. Read the instructions on the container before use. It may be better to moisten the surfaces. In any case, it is necessary to lay the mounting foam in stages, otherwise it may bend the extension strips. We'll have to tear it all off, clean it and foam it all over again.

    So, first we apply foam deep into the gap. A little, one lane. In parallel, we make strips for the entire width near the “tacks” (an example of applying foam to the door extension in the photo above on the right). The foam in the area of ​​the tacks will give the bar stability, the strip in the far part - near the joint - will press the extension to the groove, but at the same time it will not bend the bar.

    We leave the foam on the side rails to polymerize, but for now we are engaged in filling the gap from above. If it is as big as in the photo, there is no point in transferring a lot of foam. It’s easier to cut a “bookmark” out of foam, put right size wooden block. In size, it is slightly smaller than the free space. A gap of at least 1 cm should remain on all sides. But too large gaps are not needed.

    How to put extensions on an interior door: fill the top gap

    • Place small pieces of foam plastic 1 cm thick or so under the embedded part.
    • We apply a snake layer of foam on the back wall (if any).
    • We put a mortgage bar, fill the cracks around the perimeter with foam. Again, not too much, so that the foam bar does not bend down.
    • If there is a need, we put the "front" bar (in the photo above, the left bottom). If the bar is wide enough, skip this step.
    • Align the position of the trim strip with building level, secure with masking tape.

    After the first layer of foam has hardened (the time is indicated on the bottle), we fill the rest of the space. If the extension on the interior door has a significant width, it is possible (and better) to apply the foam in two stages. But each time you have to wait for the polymerization time. After that, it remains only to install the platbands.

    How to attach an extension to the door frame if it is thicker than the selected quarter

    Often the extension is thicker than the quarter selected in the box. What to do then? How to make it so that the extension rests without cracks and holds firmly? There is a simple way - to drill holes obliquely, screw in self-tapping screws, then close the holes with matching plugs. Here everything is more or less clear, but not very beautiful - the stubs are still visible.

    There is another way. Need hangers for drywall. Only they should be the strongest and thickest. From the hangers we separate the parts of the tape with perforation. Each makes two parts. You will also need small self-tapping screws (fleas). We fasten the perforated tapes to the door frame along the perimeter - at the corners, stepping back 10-15 cm, also from below, and in height at a distance of 40-50 cm.

    How to fix the dobor

    Screw the screws backing 1.5-2 cm from the edge of the box (middle photo). One self-tapping screw per piece of metal tape is enough. When the door frame is installed, the tape will stick out. These slats are thin, so even the smallest gap will not be a problem. If the extension on the interior door is the same width, just insert it. Plates due to elasticity press it tightly.

    How to put extensions if they are thicker than a quarter

    If the extension is wider, first we bend them to the front, then return them back. Due to the fact that they are not fixed to the edge, they are bent, becoming like an arc.

    This is how it can turn out - without the slightest gap

    Now we insert additional strips, leading them between the plates and the groove. They will press the bar tightly. The cracks will not be visible even upon closer inspection.

    How to install extensions: installation tricks

    Dobory for interior doors can be installed independently. The materials needed for this are inexpensive, and even a novice home master can find the necessary tools.

    Dobory for interior doors: what they look like and what they are for

    Dobory (additional boards) are wooden planks or MDF panels with which door slopes are closed. Such slopes are formed if the thickness of the wall is greater than the width of the door frame. As a result, the box does not cover the entire end of the wall and bare concrete or broken bricks are visible. Sometimes this area is plastered, wallpapered, covered with plastic, but it is easier, faster and more aesthetic to install extensions.

    The design of the door block with the use of extensions

    Unlike ordinary slopes, additional boards, as it were, continue the missing width of the box itself, forming a single structure with it. In order not to make a mistake with the tone, dobors are bought simultaneously with the door leaf and cashing.

    Benefits of using

    • Right established extras they look presentable and, depending on the overall style decision, they bring an element of wealth and luxury or restraint and solidity to the interior.
    • Attachments are fast and easy, which saves time, effort and money.
    • During finishing works the door block does not come into contact with wet solutions, which prevents it from soaking and spoiling. Extends the life of the door.

    Finished design looks nice and modern

    Dobori can make your own or buy ready-made. The store will offer additional strips of standard sizes:

    • length - 2.1 m;
    • width - 7–25 cm;
    • thickness - 6–30 mm.

    To calculate the width of the additional plank, the depth of the groove in the box is added to the width of the slope, or the width of the box is subtracted from the thickness of the wall, taking into account the groove.

    With particularly thick walls, the width of the extension can reach 40 cm or more, but such planks are made to order. The thickness of the trim strip must not exceed the width of the groove in the door frame..

    Based design features, additional strips are divided into:

    • ordinary;
    • conventional with edging ends;
    • telescopic.

    The simplest extension is a straight strip of fibreboard (MDF) or laminate without a facing edge. Many masters believe that sticking a facing edge on the ends is a waste of time and money. After all, one end fits snugly against the door frame, and the second will be closed with a platband. But in this case, the installation must be carried out with special care, because even a deviation of a couple of millimeters will give out a novice master: a gray raw edge will be striking.

    The simplest addition is a regular bar

    If the end of the extension is previously closed with an edge tape matched tone-on-tone, minor flaws will be invisible. The edge itself costs a penny, and you can stick it in a few minutes using a regular iron. This method is also preferable because the edging of the ends prevents the MDF board from swelling under the influence of moisture. This is especially true for door blocks in kitchens and bathrooms.

    A more perfect additional plank is distinguished by the presence of an edge at the ends

    The telescopic dobor has the most complex design. Its feature is the presence of special grooves that allow installation without the use of screws and nails. Moreover, it is almost impossible to miss: the dobor fits perfectly with the box and platbands. The width of the dobor is regulated by the depth of the groove. To make a telescopic extension yourself, you will need certain skills and a special tool. It's easier to buy ready-made slats.

    Telescopic door extension has special recesses

    Necessary tools and materials

    When installing extensions, a minimum set of tools is used:

    • level;
    • roulette;
    • pencil;
    • saw or jigsaw;
    • plane;
    • hammer;
    • sharp knife.
    • mounting foam;
    • fasteners (self-tapping screws, nails or "liquid nails");
    • trim strips.

    As a rule, extensions are bought together with the door leaf, but if the doors are not going to be changed, but they only plan to close the slopes, they are used to make extensions:

    • wooden planks;
    • pieces of MDF;
    • long pieces of chipboard;
    • plastic.

    If natural wood is used, it is pre-treated with antiseptic impregnations to extend its service life.

    Home-made extensions from ordinary MDF will differ from factory ones, since in industrial designs the inside between two thin fibreboards is filled with cellular material.

    Chipboards lose to wood and MDF in terms of appearance and durability, but inside the room, chipboard extensions can be used.

    Plastic as a material for the manufacture of extensions is rarely used. And if it is still used, then especially strong, metal-reinforced PVC panels are selected.

    Dobors can be made of natural wood, chipboard, MDF panels or plastic

    Installation of trim strips

    Groove installation

    If you plan to use extensions, then it is better to buy a door frame with a special groove. The presence of a groove not only speeds up the installation process, but also allows you to push / push the additional bar deep into the box by a few millimeters, which increases the accuracy of installation.

      It is assumed that by the time the extensions are installed, the door frame is already fixed in the doorway. Therefore, first measure the distance from the door frame to the edge of the wall. All slopes are measured separately and each at least four points. As a rule, these indicators differ: even if the box is installed strictly vertically, the wall itself may turn out to be uneven.

    It is convenient to take measurements with a construction square

    Additional strips are bought with a margin in width, and an exact fit is made during the installation process

    The design of the door block using conventional extensions

    During installation telescopic extensions using the tongue-and-groove method

    The upper dobor lies on the side at a right angle

    The gap between the wall and the dobor is filled with foam

    The use of foam during installation allows you to do without nails and screws

    Grooveless installation

    If there is no special groove in the door frame, the extensions are fixed back to back. Such installation requires very accurate (up to a millimeter) measurements, careful fitting of additional strips and special care during installation.

    1. Measure the width of the slopes in the same way as when installing extensions in the groove.
    2. Trim trim strips to the right sizes. If extra millimeters remain after sawing, they are cut off with a planer.
    3. An edge tape is glued onto the resulting sections. To do this, the edge is ironed with a hot iron, as a result of which the glue on reverse side melts and the tape is firmly attached to the bar.

    The edge is glued with an iron

    Nails are hammered into the end of the dobor and the hats are bitten off

    After installing the extensions, the nails are not visible

    Platband installation

    After the extensions are installed and the mounting foam has dried, the trim is fixed.

      Measure the height of the side rails. For this to the height doorway add the width of the upper trim.

    The length of the vertical casing is calculated taking into account the width of the horizontal

    A miter box will help cut the casing at an angle of exactly 45 degrees

    Marking is best done on the spot

    The ends of the platband are sawn in a mirror image

    It is desirable to bite off the heads of the nails. So they will be almost invisible.

    If self-tapping screws are used instead of nails, then a hole is first drilled into which the hat is drowned. Then they are screwed, and the caps are closed with special plastic plugs.

    At the bottom, the architraves reach the floor. Do not leave a gap for the plinth.

    The plinth only adjoins the platband

    Video: How to install dobors and platbands with a capital with your own hands

    It is not difficult to install extensions for interior doors on your own, although the process cannot be called quick. But if everything is done correctly, the new door unit will become the main decoration of the room.

    Installation of doors and architraves

    What is it for? That's when we put an addition, then the cash is inserted into it. And we can adjust the distance within this pass. About half an inch.

    Now, if we have, for example, this distance is not 8 centimeters, that's how it is here. And there from 5 to 15 millimeters, we can cash out right away without any extra. This box is certainly not telescopic. This door has been around for a long time. This is a simple box. In general, in telescopic boxes there are passes here. Immediately, so that the cash can be mounted there.

    Where do I start installing the add-on. First I saw off in height. First, I end up the bottom, then here I make a mark with a clerical knife and saw off 1 millimeter shorter.

    Then, I take a square and measure this distance from the box to the edge. And add more depth to the groove. In this case, it is 1 centimeter. And I do the markup on the back. Here is the line.

    Well, here we must take into account that it is necessary to saw off from the side where it will be inserted into the box. Because this region cannot be spoiled. Well, here I expect the additional plank to be somewhere a couple of millimeters less than to the plane of the wall itself. Because it doesn't matter here. I can adjust these 2-3, even 5 millimeters with this cashing spike. If the usual additional strips, then on the contrary, I make the width of the additional strip 1 millimeter larger. For what? That cashing in any case is enough. And you need to measure. The walls are not always level, so I measure at several points. Well, about 4. Up, around here and down here.

    If the wall is approximately flat, you can at 3 points. And I adjust, thus, the left and right additional bar. Then I mount the top one on top of them, right on them. I saw off the whole thing with a jigsaw. You can use a circular saw with some kind of parquet or mini-circular. The top bar, I mark like this.

    Here I put it like this so that this edge of it is even before the beginning of the groove. Here I also mark out, right in the groove. Knife once and for all. Then I turn it over and paste it like this. And here we already make labels, as it were, in width. Because there is a different left edge and right. This is how we make labels. Here and here. Like this.

    And then I draw and cut.

    Dobor installation

    So, now that all our typesetting strips are prepared, sawn off, we put them in place.

    Here, so that the plane coincides. I check it with my fingers.

    So, there is a right angle and up to the groove. Here's what we get.

    Like this. Why do you have to do it this way? So that when we insert cash, nothing here sticks out or interferes. And this corner will tighten up with us, that's how it will be. Here he is.

    It should be. This plane also coincides. Here she is. Here too here. Everything matches.

    In the case when, for example, a gap is formed in this corner. Well, there is no foam, for example, to rest. Here I am drilling and screwing screws. They are, as it were, an emphasis, and they prop up this whole corner. That's all. Now we will mount them. To do this, first I moisten this case so that the foam disperses better. It expands more evenly.

    Because foam expands when exposed to moisture. So, we take foam. And with such cakes I go through the entire perimeter.

    Now I take masking tape wide from me. And I fix the gain. I make sure that there is a right angle.

    And so around the perimeter. This is how I recorded it all. After about one hour, everything can be withdrawn and cashed in. I will do the same on this side as well. From the edge and from above. Everything, dobory will be ready. This mount is sufficient. There is no load here. No mechanical fasteners are required here. Here is the whole set ready. You can say now it will freeze and that's it. Propenil, fixed.

    Why do I do these dots, and not all over. Two reasons. First, saving foam. Secondly, it is a guarantee that the extensions will not be squeezed out by an arc. Because the foam has room to expand into free space. That's all. The addition has been made. This is done for a short time within 10-15 minutes. Now I will make an addition on the other door. During this time, the foam will cool down and it will be possible to start cashing out.

    Cashing out installation

    Here our dobros froze. I cut the foam, removed the tape. Now I'm going to cash out. But I will put it here at an angle of 45 degrees.

    In general, telescopic cashing, as a rule, is cut like this at a right angle here. And from the top, the cash goes in here, like this.

    But, since cashing is already installed on this door like this. So this also needs to be done on this side. How to mark up. This is how I take it and here I put a half mark with a knife. Like this. Everything, I cut off here and here.

    I put the top one first. Then I also substitute the vertical ones overlapping like this. So here I put it and make a mark. This is how it stands, for example. And I times her.

    So I put a label. Here she is, barely visible. And I cut everything. First, of course, you need to trim the bottom, and then I applied liquid nails right here on this edge. Right here. Here on this road edge, like this.

    Here, here and all the way. And I'll slap her. Because if you glue the entire groove. This glue will fill everywhere, and it will be almost impossible to remove it. It is already tight there and you just need to fix it a little bit. You can apply glue here. On the wall straight ahead, a few points. It would be enough.

    We insert everything. Maybe a little between them.

    We mount everything.

    So, here's what we ended up with. Here is such a corner.

    Here you can tint with a pencil so that this seam is not visible. Strongly will not rush into the gas. And here is everything. Everything is clear and beautiful. I'll show you how to markup. Here I put it, the knife like this.

    All. There is a label. Now we take the label like this, here. And at a right angle we hold the knife and carry it. That's it, now you need to cut diagonally. Everything goes to the market. The truth here, due to the fact that there is a groove, it becomes crooked. I just put a piece of wood here according to the thickness of this distance.

    Here I put it and it melts evenly. And I'm sawing off.

    Well, here's what we ended up with. Such is the gain. Black, hard to see, well, nothing. Now I'll show you up close.

    Everything is tight, everything is smooth, no gaps. Here is the node. Everything, the door is absolutely ready.

    All rights to the video belong to: Roman Zaitsev

    We install doors in different ways

    Dobory, or doborny boards, are installed in the frame of the door, if the width of the door frame (jamb, "loot") is less than the thickness of the wall in which the door is installed. Extensions play not only an aesthetic role, covering uneven and easily soiled slopes. (if you are interested in other ways of finishing slopes - read about them here). They, together with the platbands, also strengthen the door and prevent it from warping. Do-it-yourself installation of extensions is possible both when installing a new door, and on an existing door. We will look at the most common cases.

    Additional boards can be made independently, from a flat board, edged or tongue-and-groove, for thick walls. Waterproof plywood BS (aircraft plywood), pasted over with a decorative self-adhesive film, is very well suited for very thick or damp walls or underlayments: BS plywood does not delaminate and does not crack during fine processing of edges and does not warp from moisture.

    Door frame with extensions. The mustard color indicates the lining.

    However, most often it turns out to be cheaper and easier to use ready-made additional boards made of MDF with a decorative coating. The standard dimensions of factory-made extensions are in the range of 80 - 550 mm. For cases when it is necessary to make type-setting extensions on thick walls, extensions from MDF with a tongue-and-groove lock are produced.

    According to the standard technology, extensions are installed in a special recess on inside door frame - a quarter. However, when installing extensions on an already standing door, it is permissible to use extensions (adjacent to the door frame) and underlays (slipped under it).

    Attached extensions are recommended to be used only in dry rooms with a moderate temperature and in cases where the door is made of very high quality or may lose value from alteration (for example, if the door is an antique item or a museum exhibit).

    If the door is slanted

    If the door jamb is skewed and the deviation of the upper bar from the horizontal is more than 5% of its length, and the door leaf is fitted to the slanting frame, the installation of extensions without altering the door is not recommended. The door frame itself does not warp; its skew indicates structural defects, without correcting which the extensions will not immediately give a look, and subsequently they will warp and split.

    Tools and accessories

    To install door extensions, you will need some additional tools: a manual wood milling machine, a manual circular (parquet) saw and a clamp with a soft sheathing bed. The clamp is most needed in order to press the saw against the stool with the disc up, to get a convenient mini-circular. It is possible to tighten the clamp with a soft one by successively putting on it and heating over a gas burner at a distance of 0.4 - 0.5 m, a heat-shrinkable tube in 3-4 layers.

    Of the accessories, you will need 3-4 stools of the same height and not staggering, 4-5 wooden planks of approximately 30x30 or 40x40 mm, with a dozen wedges from the same rail and several strips (you can waste) of ordinary packaging plywood or drywall.

    Door installation process

    Base plane picking

    In the doorway prepared for the installation of the extensions, you must immediately beat off the base plane, and mark its trace on the floor with a pencil. This is exactly done by the method Pythagorean triangle (right triangle with an aspect ratio of 3:4:5; "magic triangle"). We will give explanations to the figure on how to do this:

    • Half the width of the doorway along the bottom is considered equal to three base lengths - 3l. If, for example, the width of the opening is 60 cm, then its half is 30 cm, and the base length (l) is 10 cm.
    • From the corners of the opening with a cord 5l long, we make two marks. From their intersection at point B to point O (middle of the opening) should be 4l. In this case, the OB line will be exactly perpendicular to the opening plane, and all horizontal measurements can be taken from it; the desired vertical accuracy will give a plumb line.

    Note: if you have the opportunity to use the laser projector of the base surfaces, then the described procedure is not needed. But it will not be possible to achieve the required accuracy with the help of a carpenter's or locksmith's large square: the error will be greater than the gap between the door leaf and the door frame.

    What to do if the walls are sloping

    When checking the verticality of the walls, it may turn out that they are sloped, positive or negative. If the slope does not exceed 5 mm along the height of the door, it can be reduced to zero on the surface under the casing with plaster. If it’s more, there’s nothing to be done, when cutting additional boards to size, you will also have to cut them into a wedge.

    Foam blowing

    After installing the extensions, the slots are blown out with mounting foam before plastering. The foam expands as it solidifies and creates a fairly significant pressure. To prevent the finished door jamb from this, you must follow the following rules:

    1. Do not remove the leveling wedges until the foam has completely cured.
    2. Also, do not remove the spacer bars; if they were not previously needed - install on friction, but not tight. The spacers should support the extensions, not push them apart.
    3. Do foam blowing with uniform movement around the perimeter in 3-4 steps; each subsequent - after the complete solidification of the previous one.
    4. There should be some space left from the outer edge of the foam to the edge of the slope. If you see that next layer foam will come out, stop blowing. "Re-plastering" later is better than "re-plastering" now.

    Immediately with the box

    The most technologically simple case is to install door extensions with your own hands when installing a new door along with the door frame. Such an operation is performed in the following order:

    • On the stools we lay the door jamb with the inner (opposite to the hinges) side up.
    • We align the corners to rectangularity, checking with diagonals: they must be of equal length. To do this, we temporarily nail a wooden plank to the bottom with small nails equal to the length of the upper plank of the door.
    • If the jamb is without a quarter for dobors, we select a quarter with a milling machine. The depth of the quarter should be equal to the thickness of the additional board, and its width should be equal to the depth.

    Example: additional board - 16 mm thick (standard MDF thickness). You need to choose a quarter 16X16 mm.

    • Along the perimeter of the door frame, we attach strips of plywood or drywall to the outside so that they protrude up the width of the additional board. Solid framing is not needed, two trims are enough for the top bar and 3-4 for the sidewalls. We nail plywood with carnations; drywall will have to be fixed with self-tapping screws.
    • We cut the extensions to size. The top bar of the extension should lie between the side ones, so we cut it to the size of the upper quarter, and the side ones to the size of the sidewalls of the box.
    • On both sides of the quarter we apply liquid nails or any mounting glue for wood.
    • We insert the additional boards into place and wait for the glue to set.
    • We remove the temporary lower bar that kept the extensions from falling out of the plywood and put the door frame in place.
    • Align the box to the base plane.
    • We align the box in width with the help of wooden slats-spacers; while checking the verticality of the sidewalls with a plumb line.
    • Knocking wedges under the sidewalls, we achieve the horizontality of the upper bar of the door.
    • We blow out the cracks with foam and plaster flush with the surface of the wall.
    • We nail the skirting boards, cut them to size and glue the trim with liquid nails - the door with the extensions is ready.

    Finished door and straight slopes

    In this case, in order to facilitate the installation of extensions, you need to prepare in advance a dozen and a half or two thin, 3-4 mm thick, wedges from waste plywood. After that:

    1. We knock down the plaster from the slopes and check if there is a quarter on the door frame. If yes, then it remains to choose additional boards in thickness.
    2. We cut the extensions to size, but not as described above: the top board will now fit the size of the box on top; lateral - in the size of the lateral quarters.
    3. We apply liquid nails to the inner edge of the side extensions, insert them into place. If you can reach a quarter, it is better to apply glue to it.
    4. We adjust the height of the dobors with wedges from below, as described.
    5. We insert in turn the spacer strips, pre-cut to the width of the doorway, and we support the extensions from the side of the slope with thin wedges so that they do not fall out. We check the verticality of the extensions with a plumb line; better - just two, suspended in advance.
    6. We apply glue not to the tops of the side extensions, to the inner edge of the upper extension board (or a quarter), and lay the upper extension board.
    7. After the glue has hardened, blow it with foam and decorate as described.

    If there is no quarter and with inclined walls

    If the door frame is without a quarter, then there are two options:

    • Reverse quarter. With a milling machine, we remove a quarter on the extensions, 10-15 mm wide and half the thickness of the extension. With “not very” inclined walls, this option is convenient in that a quarter on the extension can be made oblique in width, and such an extension will hold no worse than “normal”.
    • If the walls are brick, then you can knock out a groove in the slope under the door frame, and put underlays. This option is convenient for those who do rough work with a lot of effort better than light, but thin.

    In both cases, the extensions are installed with the help of auxiliary thin wedges, as already described.

    slope slopes

    If the slopes of the doorway with a slope (expanding opening), then, regardless of whether new door or an existing one, the extensions must be placed at the standing door. The fact is that when installing direct extensions, you get a very wide gap. After blowing foam behind the casing, there will be a space where the plaster lies on the foam. Sooner or later cracks and/or dips form there.

    Therefore, before installing extensions in openings with inclined slopes, the inner edge of the extensions must be brought to a wedge along the length, as marked in the figure with a red circle. After trimming to size, the extensions themselves will take the form of a trapezoid. Otherwise, the installation of extensions in this case has no special features.

    Interior doors

    As a rule, extensions are installed on the side opposite to the door hinges. But when installing the extensions of interior doors, it is possible that they will have to be installed from the side of the hinges. If so, then you first need to check whether the extensions interfere with the opening of the door.

    If with a fully open door between its edge and the edge of the door frame there is a gap equal to the thickness of the extension with a margin of 2-3 mm, there is no problem: we put the extensions in any of the ways described above. If the edge of the door is adjacent to the edge of the box, you need to put underlays, having previously knocked down the plaster from the slopes. This should not be neglected: only 1.5 mm of “pressing” the sash to the extension eats up 10 degrees of its opening angle, not to mention the fact that the extension will soon be damaged.

    Read about the full cycle of interior door installation here.

    steel doors

    It is possible to install extensions on steel doors only with lining ones. There is a nuance here: along the length of the extensions, along their inner DECORATIVE side, at a distance of 10-12 mm from the edge, you need to use a circular saw to select a groove with a depth of a third of the thickness of the extension and a width in the thickness of the corner from which the door frame is welded plus 1 mm. It is for this groove, when the edge of the steel door frame enters it, the box will keep the extension with it.

    More information about the installation nuance entrance doors can be found at the link.

    Type-setting extensions

    When covering walls with MDF panels, laminate, etc. The selection of the door frame can be done in typesetting from pieces of sheathing material, longitudinal or transverse. But technologically, such an operation already refers to the technology of wall cladding, and not the installation of extensions.