Proper installation of extensions on interior doors depends on a number of factors. But as practice has shown, not all amateurs even know what extensions are, so further we will look in detail at the types of extensions and the rules for choosing them, and home craftsmen will learn how to install extensions on an interior door with their own hands, and step-by-step instructions will be given in 4 options .
With large thickness of walls and partitions, extensions on interior doors act as compensators
What you need to know when choosing extras
The selection is made for a specific doorway, after all the necessary preliminary measurements. When machine operators are given technical specifications for the manufacture of doors, the additions immediately fit into the specification.
Types of additions
There are:
- Straight, with a flat end joint, when the end of the board is tightly joined by pressing it against the box and the trim with an adhesive layer.
- Telescopic. With a groove connection, where there is already a protrusion for this. It is also telescopically connected to the platband.
Size and materials
Separately, an extension with a flat end connection, that is, a straight one, is purchased. They are bought in large construction stores, which have a small production facility for fine-tuning products in terms of trimming something, sawing it off, etc. The length of flat trims is 2200 - 2300 mm for vertical strips and 1000 for upper horizontal ones, that is, they are produced with some length reserve. Telescopic extensions that have entered the trade are already strictly unified with specific models. Or the store has an agreement with a company that produces “frame + door leaf + trim” kits for the prompt production of a telescopic extension for this model. This is not difficult to do, keeping in mind the standard articles adopted by the manufacturer, and if the enterprise is within walking distance.
The standard (or often simply accepted by most manufacturers) width of straight additional strips is from 95 to 215 mm. Telescopic ones are somewhat narrower - from 95 to 165 mm. But since the telescopic extension is a functioning, full-fledged adjustment mechanism, by sliding the extension tenon in or out of the door groove, you can increase the thickness of the wall covered by it, as in Fig. "Adjustable telescopic extension."
The standard material for extensions is solid wood. Moreover, if the box is made from a specific type of wood (pine, birch, cedar, oak), then the accessory for it should be purchased (or it is already included in the kit) from the same type of wood.
Solid wood panels are the most environmentally friendly, beautiful and durable. Although they are also made from MDF, they are covered with the same material as the frame, trim or door. And this is veneer, eco-veneer or paper (polymer film) with a pattern that imitates wood.
What are the benefits of extras?
The first is aesthetics. Wood always looks attractive. Wallpaper, plastic, and the most beautiful plaster will look alien between the wood of the box and the trim.
The second is the possibility of quick installation. A professional can complete the installation of the extensions in an hour; an inexperienced person, working carefully and according to the instructions, will do it himself in 2-3 hours.
Third, it can be dismantled without damage and then reassembled. This may be necessary if you need to install hidden cables, wiring, or any communications in general.
Fourth, the opportunity to purchase additional accessories of any cost, from budget to luxury, made from valuable wood that matches the door covering material.
The need for extras.
- They are installed so as not to make a complex and load-bearing element in the form of a door frame the width of the doors. Considering the high cost of products made from natural wood, the box with extras will differ in price from the standard one by 2-3 times.
- The extensions hide all defects in the cut surfaces of the opening.
- They serve as decoration.
- Additionally, the rigidity of the “frame-platband-extension” system is increased.
Subtleties of choice
When choosing an extension, they are guided by the material of the remaining parts of the door system. In budget models, where the material for boxes and canvases is MDF or, less commonly, chipboard, the coating is made of eco-veneer, technological chips oriented in one direction, glued together under pressure with epoxy or polyester materials. Or even just from a special film painted to match the texture of wood.
If all the parts are covered with veneer, then the additional trims, purchased separately or included in the kit, will be veneered. In addition, the texture pattern and type of wood used matters.
Selection of planks to size
Straight extension strips are selected strictly according to the width of the wall masonry not covered by the frame in the opening. The telescopic sample may differ from the wall thickness by 30-40 mm or as much as the extension tenon extends from the groove of the box. However, at least 10 mm should still remain in the groove - for reliable rigidity of the assembly.
Types of extensions for interior doors and features of their installation
Author of the article: Alexandra Ivanova December 29, 2020
The additions allow you to hide the opening between the door frame and the platband during the installation of swing doors, and to create a partition when installing sliding door structures and portals. From the article you will learn about the types and features of additional strips, methods of their installation. A description of the installation technology will help you install the additions at home yourself.
Materials and sizes
Depends on the thickness of the wall and the weight of the door leaf. After all, the wider and more massive the door, the more durable the material of the additional strips should be - this is especially true for telescopic products that take on part of the weight of the structure.
As for specific sizes, in the absence of a unified standard, manufacturers have adopted the following unified values (Thickness x Width x Length):
- 10 x 50 x 2 350
- 10 x 100 x 2,350
- 10 x 150 x 2,350
The material from which the doors are made is selected either similar to the material of the doors (unification in appearance) or, conversely, according to the designer’s plan, differing in color and texture. It is not allowed (for purely aesthetic reasons) the combination of natural veneer or polished solid wood frames and doors coated with paper or polymer finishing. This combination looks “cheap”.
What are the accessories made of?
Material of manufacture
- Solid wood.
- MDF.
- Fiberboard.
- Chipboard.
Either covered with paper or laminate, or eco-veneer or natural veneer, but in appearance they will in any case repeat the external finish of the remaining elements of the door system.
Kinds
Industrially produced decorative strips for door decoration are produced in the form of monolithic panels up to 3000 mm long. What types of additions there are for interior structures is described below.
Standard without edge
Such parts are slats with a width of 70 to 250 mm and are made of MDF, fiberboard, laminate or plywood. The side parts of the board do not have a covering and are in direct contact with the frame of the interior door and the platband. During installation, you must be careful and carefully check the gap, since if it is skewed, the raw edge of the finishing strip will be visible.
If necessary, the ends can be covered with film yourself. To do this, you will need to purchase material of a suitable shade and glue it to the edge.
Standard with edge
Products are available in the same width as without edges. The only difference is the factory-coated edge with film or natural veneer. Industrial coating ensures uniform and tight contact with the surface, which prevents MDF or chipboard from absorbing moisture. Therefore, closed edge panels are preferred for interior doors installed in bathrooms or kitchens.
Telescopic
For large wall thicknesses, a telescopic extension of the interior door is used, and this is also an ideal solution if the size cannot be determined accurately. The design is similar to a clapboard. On the edges of such products there are ridges and grooves, with the help of which individual strips are assembled into a monolithic structure, and also to obtain the required size. Assembly and installation of the telescopic extension is carried out without the use of any additional fasteners, and the width can also be adjusted.
Combined
Such products have an angular shape and act as an extension and platband for the opening. Like other types, these extensions can be made of MDF or plywood and covered with natural veneer or film.
Rules for calculating the size of the addition
To determine the dimensions of the extensions, first, the linear dimensions of the doorway are determined by measurements, and this is done more than once and sequentially from the floor to the top point of the opening and between the verticals, focusing on the shortest measurement lengths. Then, after installation, there should be gaps in these places to fill with foam, 10-15 mm wide. And if we proceed from the old and most demanding GOSTs, then
- there should be a gap of 20 mm between the mounted box and the surface of the opening;
- there should be a technological gap of 3 mm between the door and the hatch around the perimeter;
- if the frame has no threshold, then the gap between the floor and the bottom of the door should be at least 8 mm.
Do-it-yourself installation
Metal door trims differ from those for interior doors in width, weight and the way they fit to the wall. The fact is that additional thickness of standard thickness is unlikely to adequately cope with maintaining the load on the structure, so support battens are made for it on the wall of the opening. Its additional function, in addition to support, is also thermal insulation, which is important for an external door. After all, the cells between the sheathing can and should be filled with polyurethane foam.
If the extension is metal (only covered with decorative wood trim), then the sheathing is also made of metal (usually aluminum). A wooden sheathing is placed under the wooden paneling.
If the extension is not included in the package of the purchased metal door, then its width in the opening is determined by measuring the distance from the frame already fixed in the wall to the outer edge of the opening in it. In such a way that the ends of the additional planks are flush with the wall.
And the ideal material for a loot with a metal sheet would also be a metal profile. This way you will end up with a structure that is uniform in its strength.
In interior doors everything is simpler, all the parts are wooden or plastic, and they are much lighter.
Taking dimensions, making blanks
Using a building level you need to determine the horizontality of the upper part of the opening and the floor, and using a plumb line to determine the correctness of the vertical (the wall may be somewhat tilted into one or another part of the room, and the long vertical parts of the opening may also be skewed). When measuring an opening in a wall, they are guided by the narrowest part, taking into account all the irregularities in the linear dimensions of the edge of the opening. To determine this narrowest place, a straight, non-curved, wooden or metal strip is placed in the opening along a plumb line, the places in the opening where the wall touches this strip are marked, and then the opening is measured from these extreme marks.
Such measurements will give an idea of the external dimensions of the future already installed door frame.
We collect
- A tape measure and a corner. Or, using one corner, if there is a measuring scale on it, take measurements from the box to the end of the wall. If you work with only one tape measure, there may be distortions due to the fact that the measurement deviates from the horizontal, and then millimeters play a role! Measurements are taken at least 4 points vertically and 3 points horizontally.
- If the opening is deep and non-standard, it is calculated how wide the additional extension is needed for splicing. Or it is immediately purchased (or ordered) in the required width.
Connection to box
There are no problems with the compatibility of the telescopic extension and the box; everything is installed in the groove. By pushing or pulling the bar into the selected quarter, it is adjusted close to the platband and secured. We must remember that the upper horizontal bar rests on two vertical ones (and does not fit between them, hanging) so that the letter “P” is formed, as it were. And when marking the width, you need to consider whether there is a groove there and what size it is.
A short upper horizontal line is inserted into a quarter of the mounted box, and using a level and wedges, it is leveled strictly horizontally, and then it is fixed to the wall and the box with masking adhesive tape.
Then, also, only using a plumb line, spacers and wedges, the vertical extensions are correctly installed. The gaps between the wall masonry and the finishing that remain after installation are filled with foam.
Fastening the extension
Direct grooveless extensions are placed on finishing nails, screws or foam. You just need to remember that when installing on nails, it is advisable to first drill holes for these nails with a diameter smaller than the nails themselves - otherwise there is a risk of splitting the wood. However, it is useful to have the same holes for self-tapping screws.
Sequence of operations:
- The planks are cut to size - since there is no need to add width due to the lack of grooves. The cutting areas are trimmed with a plane.
- An edge tape is glued to the finished ends and this tape is melted with a hot iron along the wrong side.
- The side planks are installed taking into account the movement of the horizontal plank and its support on the side ones (when working with straight extensions, it is installed last).
- Finishing nails are driven halfway into the ends on the hole side and the heads are bitten off diagonally with side cutters. Then they place the trim in the right places so that the edge tape is pressed against the box, and evenly tapping the trim along the end with a mallet or hammer, alternating with a wooden spacer, nail it with the already partially secured nails to the box. It is important that at this stage the addition lies without distortions.
- With self-tapping screws, the picture will be the same, only instead of hitting with a hammer, the self-tapping screws are screwed in. The heads of the screws or the places where the finishing nails are driven will then be hidden by the platband. To ensure that the heads of the screws do not interfere with the fastening of the casing, a countersunk depth is drilled under them using a larger drill to the length of the cone of the head (measured with a caliper or specified in the store).
- The horizontal part is laid last, checking the corners and horizontals and also fastened to nails
Foaming
When the extensions are sized, they are placed close to the box and leveled using a plumb line, level, wedges and spacers. Before foaming the cracks, the surface is treated with water. The easiest way to do this is with a spray bottle - at least for indoor plants. Then the adhesion of the foam will be perfect. Polyurethane foam is an ideal glue, so that after it hardens, the extension will sit firmly in the opening.
How to install the extensions yourself - 4 options
The question of how to install extensions on an interior door is not straightforward; there are many related factors, so instead of one instruction we will consider 4 options.
Option #1. Arrangement of extensions using false slopes
This option is great for a bare doorway when the frame has not yet been installed. We will attach the additional strips to the frame separately, and then we will insert it all into the doorway as a single block.
If you are at the design stage, it would be a good idea to learn the rules for measuring doorways; they are described in detail and shown in the video “HERE” .
| Scheme | Recommendations |
| Select a groove The vast majority of door frames already have a groove for the additional trim; if there is no such groove, then you will need to take a hand cutter and cut a groove measuring 10x10 mm around the perimeter. | |
| Is it possible to do without a groove? The method outlined below allows you to do without milling, but the extension will have to be perfectly adjusted, which can take a lot of time and effort. | |
| Prepare a false slope It is easier and cheaper to use wall plasterboard for a false slope, but instead you can take any sheet, for example, plywood, chipboard or MDF. You need to cut the lining according to the thickness of the wall and attach them to the box; first, the gypsum board is glued.
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| Additional fixation of false slopes of gypsum boards can be glued to PVA or any of the polymer types of glue, for example “Liquid nails”, but one glue may not be enough, so we additionally screw each plate with self-tapping screws. | |
| How to attach accessories Step 1 When the false slopes are secured, we proceed to installing additional strips; they are inserted into the groove of the box and glued to the inside of the slopes. The top strip is glued first.
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| Step 2 Next we glue 2 side strips, they are also inserted into the groove of the box and fixed on the false slope. If there is no groove, then the edge of the extension must be perfectly smooth, plus any glue that comes out during joining must be removed immediately. | |
| Horizontal box adjustment We have already assembled the box with the extensions, then we insert it into the opening, after which the structure needs to be adjusted horizontally. The principle is simple - a level is applied to the lintel and wedges are tapped on the right or left as necessary. | |
| Adjusting the box vertically After setting the horizon, we proceed to adjusting the box vertically. Here the technology is similar, wedges are driven in on the right or left. | |
| Fixing the box with foam Our entire structure is fixed with polyurethane foam. The gap is first sprayed with water and foam is gradually poured in. To prevent the foam from bursting the box, transverse struts are installed.
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Polyurethane foam is poured in fragments around the perimeter and is added as it expands. If the composition is poured without gaps, then even foam with low expansion can crush the structure.
Option #2. Installation of extensions on metal supports
This method is cheaper, simpler and faster than the previous one, but in this case it will not be possible to do without a groove for an extension around the perimeter of the box.
| Photo | Recommendations |
| Selecting a suspension Hangers for plasterboard structures are used as the main material. It will take a maximum of 3 – 4 hangers to arrange the doors. The price for them ranges from 15 to 20 rubles.
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| Cutting the hangers Now, using metal scissors, we cut plates of 5–7 cm from the hangers. | |
| Screwing the plates The plates are screwed to the box with self-tapping screws and a press washer. The distance from the edge of the box to the self-tapping screw is 15 - 20 mm. The fixation step is 25 – 30 cm. | |
| Bend the plates Now we need to make a kind of springy arcs from all the plates. To do this, bend each plate inward and bend it back a little. | |
| Inserting the extension When we insert the extension strip into the groove, the plates will press it tightly against the frame, and on the reverse side the strip will be fixed with a platband. As a result, we get quite a decent gain. |
Option #3. How to fasten the extension with self-tapping screws
In theory, screwing the strip to the door frame with self-tapping screws is not difficult; you need to drill a through hole at the end of the extension, and then screw the strip to the door frame through this hole. The method is suitable for boxes, both with a groove and without a groove.
But at the amateur level this is a very dangerous undertaking. As already mentioned, the thickness of the trim varies between 10 - 16 mm and the master needs to drill this strip with a thin drill (diameter 3 mm) without the slightest distortion. Otherwise, the drill will come out from the front or back side of the extension.
From experience I can say that with this method of fixation, the maximum width of the extension is 100 mm. If you do not have experience working with thin strips, then the only option is to use a drilling machine, otherwise the likelihood of successfully drilling out the extension with a hand drill tends to zero.
The arrangement technique is simple:
- A series of through holes with a diameter of 3 mm are drilled at the end of the bar;
- The holes are countersunk for the screw head;
- Long self-tapping screws are screwed into the holes until they come out on the reverse side;
- The extension is pressed against the box in such a way that the screws leave marks on the box;
- According to the marks, holes for self-tapping screws are drilled already in the box;
- The plank is put in place and the screws are screwed in completely;
- The heads of the screws do not need to be decorated, as they will later be covered with the trim.
How to attach extensions to an interior door with self-tapping screws
Option number 4. Planting extensions on polyurethane foam
This method is considered one of the simplest; it is designed for cases where the door frame is already installed and has a mounting groove.
| Photo | Recommendations |
| Measuring the wall for addition The distance from the box to the edge of the wall is measured with a construction square at 3 - 4 points on each side.
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| How to cut off the extension Additional strips are marked according to the dimensions taken earlier. For cutting laminated or veneered MDF, a hand-held or stationary circular saw is best suited. But in the absence of one, you can get by with a jigsaw, just to prevent the jigsaw from leaving chips, stick masking tape on top.
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| We knock down the box. After cutting, the additional strips are tried on in place and knocked down separately. It is more convenient to fix with thin nails. You can take self-tapping screws, but you will need to drill holes for them. | |
| We insert the frame from the extensions. We insert the structure we knocked down into the grooves of the main door frame and lightly fix it with paint tape. | |
| Spray the base with water. Polyurethane foam adheres better on a wet surface, so we spray the perimeter with water. | |
| Blow out the polyurethane foam. The foam is poured in horizontal stripes at intervals of 80 - 100 mm. As already mentioned, we take foam with a low expansion coefficient - 65 units. |
Do-it-yourself additions to interior doors video:
The last step after installing the extensions on the interior doors will be the installation of platbands, the topic is quite broad, detailed instructions for installing several types of platbands with photos and video materials are “HERE” .
Installation subtleties
| Before foaming and wetting with water, it is advisable to clean the stone or brickwork of the wall from dust, to the extent possible, blow it out with a rubber bulb or a bicycle pump, a compressor for inflating car tires - it’s up to you to decide. |
And another important point: when installing vertical planks, use spacers ALWAYS! In 2 places - approximately 60-65 cm from the floor and at the same distance from the top of the box - otherwise the foam filling the gaps will bend the extensions in the middle.
An element fixing the door frame such as liquid nails or foam is generally preferable, no matter what the door installation manuals say: not self-tapping screws, not finishing nails, but foam, which, unlike self-tapping screws and nails, has the most gentle effect on door elements .
Installing an extension to the box when it is thicker than the selected quarter
When installing any parts with your own hands, sometimes situations arise when it is not possible to purchase a thickness die that is correctly correlated with the selected quarter on the box.
In order for the extension to be attached to the opening with a minimum of cracks and to hold tightly, perforated aluminum tape is separated from the drywall hangers. When hung, it turns out to be two parts. Using small flea screws, these parts are screwed along the perimeter of the box with an indentation of ten centimeters from the corners, as in Fig. “Punched paper tape for attaching extensions.” The screws are screwed in, retreating 1.5-2 cm from the edge of the box, one per piece of tape, which will be enough. True, after installation in place, the edges of the tape will protrude a little. But with thin slats, due to elasticity, the plate will be pressed tightly and it will be hidden.
With a wider selection, the plates are first pressed onto the front part, and then returned to place by wrapping it. Now it is enough to insert the extension with the winding of its strips between the groove and the plate, and they will be clamped. You won’t notice any cracks even if you look closely at the surface. (Photo “We put extras thicker than a quarter”).
The final look is like this (photo of the same name)
How to determine the required thickness
The thickness of the additional board should not exceed the dimensions of the groove in the box. The average value ranges from 10-16 mm.
Factory strips are produced in standard sizes, depending on the parameters of the partition:
- if the wall width is up to 9 cm, then the thickness of the decorative insert is 1.5 cm;
- up to 16.5 cm - 1.5/2.5 cm;
- up to 26.5 cm - 2.5 cm.
The maximum thickness of finished panels is 3 cm. For non-standard openings, extensions are made to order.
For interior structures, planks of average thickness up to 1.4-1.5 cm are sufficient, and for entrance doors it is recommended to use extensions of 1.5-2.5 cm or more.
What to do with parts of inappropriate sizes
Each woodworking company has its own standards for the width of planks. For example, instead of 50 mm, the minimum width may be 60. Or 75. If the dimensions of the doorway do not fit into any standard produced by factories, there are three ways to solve the problem:
1. Purchase of two straight planks and joining them (splicing),
2. Buying a larger width strip and cutting it to the required size,
3. Purchase of a telescopic extension with adjustable width.
Tools and accessories necessary for work
The tools listed below are usually either already at home, or can be purchased, asked from friends, or rented.
- Plane. It may be necessary if there is a measurement error and a wall protrusion that interferes with the installation of the frame dimensions already calculated for the door leaf.
- Carpenter's pencil and construction knife with replaceable blades.
- Hammer.
- Roulette up to 3 m.
- Construction corner.
- A jigsaw or at least a sharpened hacksaw with a fine tooth. As a last resort, use a grinder with a special cutting wheel. If you have a hand-held circular saw with a sliding support ruler, all problems disappear altogether.
- Clamps.
- Plumb.
- Level.
You may also need a compact machine for manual milling - but an untrained person should not use it, it is very dangerous.
Telescopic platband and its structure
A telescopic platband is the same in appearance as a regular one, and can be a flat, corrugated wavy or slightly convex strip, which is installed frontally around the doorway and serves
- to hide installation marks;
- for the aesthetic final design of a door frame mounted in a doorway.
And it is telescopic because it fits into a groove with a protrusion. Due to its movement back and forth, there is an overlap of part of the box that needs to be covered for one reason or another. Or simply complement its look aesthetically.
Telescopic platbands with an additional strip are considered an expanded version of the simple one, as they allow you to increase the width of the tray up to 150 mm without creating a gap.
To file the platband at an angle of 45⁰, use a carpenter's miter box. This is the best option for sawing off according to a template, because no amount of measuring along the angle using a protractor will give an ideal cut for a reliable and imperceptible joint of the platband at an angle of 90⁰.
Types of additions and their features
Additional trim strips are not installed on all doors. But only in openings whose width exceeds the dimensions of a standard frame for swing doors - 140 mm. Such elements are needed only when decorating wide partitions. Also, extensions are indispensable for the design of portals and openings of sliding doors.
Additional elements are made from MDF, chipboard, natural wood; plastic and metal are less common. The most common material is MDF. Manufacturers perform decorative coating only on the front side.
Manufacturer sizes of extensions can vary significantly from line to line. Here's an example of averages:
When choosing additional elements, the following nuances should be taken into account:
DIY installation
First of all, they are guided by the rule: purchase structural parts of a size slightly larger than what is actually needed, since the doorway “walks” with an error of ±5-10 millimeters. This will allow you to make any necessary corrections in the future.
In a standard or non-permanent partition made according to specifications, the thickness of the walls rarely exceeds the overall dimensions of the products. But if this still occurs, then an additional set of appropriate dimensions is purchased. The L-shaped platband with its curved edge, perpendicular to the plank, then fits into the grooves of the boxes and extensions on both sides of the wall.
If the installation of the extension is carried out on an already installed frame, if the surface of the openings is even, problems usually do not arise. The best option for fastening parts in such cases is foaming. This will not only securely secure the entire structure, but also avoid damage to the wall and wooden parts of the doorway. In this case, the top of the extension is always installed first, then the vertical components are measured and shortened to the required size. Spacers are attached to the extension strips, the planks are first tapped to the wall, the gap between the wall and the planks is foamed, and after complete polymerization of the foam, the spacers are removed, the excess foam is cut off and the casing is attached to the extension tenon until it stops.
Post-installation elimination of gaps
Having installed the doors and mounted the extensions, they are faced with the need to seal the cracks. And they, even if very insignificant, will definitely be there. To remove them, all installation elements are aligned: the extension is fixed against the wall and frame with masking tape, and then wedges are driven into the gap between it and the wall, and this gap is finally foamed.
The time for complete polymerization of the foam is indicated on the cylinder, so only after waiting for it to expire, the platbands are finally installed along the entire perimeter of the opening on the sides of the wall. After installing the expansion, the step-by-step steps look like this:
- The height of the opening is measured, which consists of the length of the vertical trim plus the width of the casing.
- Using a miter box, the upper part of the casing is sawed off, maintaining the orientation of the cut in the desired direction (one casing is sawed off to the left with the long side, the second to the right). The top strip of the platband is sawn off obliquely with the short side in one direction.
- Holes are drilled and platbands are installed, fixing them on several nails driven in halfway with bitten off heads.
- The side trims are placed with their bottoms supported on the floor, then the top strip is attached. The structure is leveled and in order to prevent it from becoming loose, it must be immediately fixed with nails. There are six to eight side (vertical) trims, three to four on the top.
Features of installation of telescopic bars
Installing panels with grooves is quick and easy. The wall and side of the box are pre-cleaned. The extensions are tried on, the excess is cut off. The top (horizontal) element is installed, then the sidewalls. The planks are inserted into the grooves of the box to the required depth: the panel should cover the open sector of the wall. The end of the bead is tapped with a mallet. The panel is attached to the wall using liquid nails. The horizontality and verticality of its surfaces is checked by a level. At the end, the platbands are put on. If the opening has a depth exceeding 15 cm, the telescopic bar is assembled from two or three parts. The stackable telescopic panel will firmly fix the frame, ensuring the reliability of the door structure.
Immediately with the box
Sometimes the extension is installed on a box that has not yet been inserted into the opening. This method of installation has its advantages, since everything being mounted lies on a horizontal surface (preferably on a workbench or large table, but 4 stools of the same height in the corners of the assembled structure will do).
- The parts of the box, laid out in order, are stacked with the inner side facing the door facing up.
- Angles are leveled up to 90⁰. This can be done with a cord or thread, pulling them diagonally until they are equal to the millimeter. Then I fix this position of the box with a temporarily nailed bar.
- Along the perimeter, this entire structure is sheathed with plywood or plasterboard, with their protrusion upward outside the box, so that later the protruding parts of the extensions can be fixed along them. The result will be a structure that fits exactly into the future opening. The extensions are cut to size, and the top strip is glued first, the length of which will touch the limiters installed on the sides. The second to be planted on the glue are the side extensions.
- After the glue has dried, the retaining strips are removed.
- The entire assembled structure is placed in the doorway, fixed and leveled using a level, plumb line and wedges, and then secured with anchor bolts or long self-tapping screws.
If there is no quarter and the walls are slanted
If the quarter was not selected, you can do this:
- Having delved into the wood ½ of the thickness of the extension and taking a width of 10-12 mm, make the reverse quarter with a hand router. In case of a slight slope of the wall, a quarter can be made oblique in width; this will not affect the tightness of the elements.
- Or you can knock out a groove in the brick wall for the frame and insert a backing board there. This option may be preferable for those who find it easier to do rough and labor-intensive work instead of delicate work that requires saving energy.
In both cases, the extensions are installed by adjusting thin wedges, as is the case with straight slopes.
Slopes with slope
When the doorway widens upward or downward, the extensions are installed with the door already in place. This will prevent the door frame from moving away from its normal position. In this case, it is necessary to bring the inner edge of the extension into a wedge, and the extensions themselves in this case acquire a slightly trapezoidal shape. If this is not done, in the wide gap of the place where the doorway widens, after the mounting foam there remains a space where the plaster adheres to this foam. This means that cracks will inevitably form there, and a piece of the wall may become loose, crumble and begin to fall out in pieces.
How to choose the right additional elements
The first thing you should pay attention to when choosing a material for additional products is their compatibility with the door leaf. As mentioned earlier, for reliability and harmonious design they must be made from the same raw material. It is best to purchase the elements together with the doors.
The quality of the chosen material is also extremely important. The plank should not have any chips or cracks. A flat and smooth surface without defects indicates the good quality of the product.
If your choice fell on telescopic extensions for interior doors, then in this case, first of all, you need to make sure that fasteners are available. These must be special factory grooves, the shape and dimensions of which are individually selected for all interior doors.
It is worth taking into account the price-quality ratio of the selected product. It is best to give preference to trusted brands and manufacturers. Cheap analogues are unlikely to be high quality.
Before purchasing a product, you need to calculate exactly how many additional elements are needed. As a standard, 2.5 slats are installed on the door.
DIY door frame
Most often, making a door frame with your own hands is undertaken by those who have non-standard doorways, have well-seasoned and high-quality wood on hand, the area required for the work and at least the minimum of the tools listed in our material. Or those who managed to purchase a non-standard door leaf (usually imported), but will have to wait a long time for the necessary parts from a woodworking center located far from the site, and there is no guarantee that they will do everything correctly.
The fact is that non-standard products included in the door set cost one and a half, two, or even three times more than standard ones. In mass production, this is due to the need to reconfigure machines, develop a separate specification, that is, due to the fact that labor and means of production are turned off for a long period from the production process that generates profit due to the conveyor method. And to compensate for this, they raise the price of products many times over.
But it is not necessary to have such a labor-intensive part that requires a very expensive milling machine, such as the riser of a box with a quarter - you can make a composite box, as in the corresponding photo with the same name (photo).
Bars are cut from a board x50 mm, driven with a plane to size and self-tapping screws with preliminary drilling of holes of a smaller diameter, so as not to split the wood (especially at the ends); two bars of size are attracted to one another, forming a quarter.
You can even, if you have a not so expensive (or rented) hand router, make a groove for the future tenon of the extensions or for the sealing strip.
A box is prepared according to the size of the purchased canvas, which must meet the following standards:
- There should be a technological gap of 3 mm between the door leaf and it.
- There should be a gap of 20 mm between the edge of the opening and the top of the product. If everything sits on foam, there should be a gap of 20 mm along the vertical parts of the structure.
- The gap at the bottom, if the frame with a threshold or the bottom of the door should be from 5 to 15 mm - for dry rooms and up to 50 mm - when the room is wet.
Note:
| Boxes with a threshold are usually an attribute of purely entrance doors. Using thresholds on interior doors is impractical and sometimes prohibited by safety standards. |
How to take measurements
After final installation, a technological gap of 3 mm around the entire perimeter is required between the canvas and the box. Therefore, when installing the box, the internal distance should be 6 mm higher than the calculated one (3 on each side, and this also applies to the top of the door). And the outer distance, between the outer edge of the box and the wall, is 14 mm. If you decide to take the original bars of a different size (usually this is done if there is a heavy metal door, and the frame is made of wood), then compare the dimensions of the doorway itself with the future dimensions of the outer part of the box - sometimes it is expanded for such a case.
If the old frame has already been dismantled (and this is desirable), the doorway is measured in at least 5-6 places. It’s better to attach a straight plank to the wall and visually, with marker marks, immediately determine where the largest protrusions are located. In the future, either focus on them, or, if this operation is not too labor-intensive, bring them down to an acceptable level.
To ensure that the box is made correctly to size, you can measure both the size of the purchased canvas and the opening with the old box already dismantled.
Connection of the vertical and horizontal parts of the box
Can be done at an angle of 45⁰. But for this you need either a miter saw with the desired slope set on a scale, or a good miter box.
Important point!
| Make no mistake! The length of the vertical and horizontal elements of the box must be measured from the extreme points of the bevel and must take into account the thickness of the hacksaw blade or circular miter saw! Therefore, for example, in the length of a vertical box element of 2000 mm, it is necessary to add the thickness of the hacksaw blade (for example, 2 mm) before sawing off the bevel. Believe me: later, these 2 mm, if you don’t add them, may not be enough for you, and you, cursing, will push the door tightly into the frame every time, closing it. |
Or the connection is made at an angle of 90⁰. True, you still have to use a miter box for sawing. (photo “methods of connecting box beams”). This is the so-called “mortise method”, and it is better to do it if you already have carpentry skills.
If the size of the wooden blanks and their quality allow you to make a wide box, you can resort to this option in order to avoid adding extras.
