Replacing a window sill or installing a new one with your own hands is the most important moment in installing any type of window. The fact is that it is designed to play not only an aesthetic role in the interior, but also a protective one. It is on him that all kinds of temperature changes and mechanical loads are constantly affected. It is he who suffers from constant exposure to moisture and the rays of the sun. And it is all these moments that largely determine the features of its installation.

The materials used for the manufacture of window sills can be very diverse - wood, PVC, marble, etc. And, of course, all the nuances of the installation will depend on them to some extent. However, for this action, there is still a general list of recommendations that allow you to navigate the work algorithm itself.

1. The window sill is fixed inside the room and below the window opening;
2. Below, on the windowsill, at a maximum of 60 mm from its edge, there is a gutter - a teardrop up to 20 mm deep, necessary for draining water;
3. The final stage of installation begins only after the preparation of the lower plugs;
4. The lower part of the solution of the side slopes is cut down to the wall. Then the wall is cleaned of debris, dust, dirt, etc.:

The window sill is placed like this:

• So that the board is in a strictly horizontal position (measured using a level), and the transverse slope of the window sill inward from the window box is approximately 3 0;
• The wedges, which are the basis for the installation, should not extend beyond the wall. Therefore, with their correct installation, they will require additional fixation with plaster.
• After that, they proceed to the removal of the window sill, wetting the wall with water and covering it with a lime-gypsum mortar, so that the level of the solution exceeds the level of the wedges by 15 mm;
• The window sill is placed in the solution and pressed against the wedges with force until it stops;
• At the last stage, the excess mortar is leveled and pressed flush with the wall plaster, followed by its rubbing. At the same time, the window sill itself enters the groove made on the bar at the bottom of the box. In relation to the side slopes located in the lower part, the same actions are performed - smearing with a solution and subsequent mashing.

It is possible to correctly install the window sill, so as to exclude its subsequent bending and breaking, by placing metal strips under it and inserting the ends of the latter into the lower plug. However, most often you have to deal with plastic and wooden window sills, during the installation of which strength and reliability can be achieved in your own way for each option.

Algorithm for installing the main types of window sills

Plastic

Installing a plastic window sill is very simple. Any special skills and abilities are not required here. It is extremely important to be extremely careful in the process of sawing PVC, when you should do without strong pressure so that scratches and chips do not appear at the cut site.

• First, a cleanup is carried out;
• Then, using the horizon level, they expose the window sill using beacons. By the way, when installing a window sill, it is tilted down by 5 mm so that the moisture accumulated from condensate does not linger, but flows down;
• The free space is filled with mounting foam, the excess of which is subsequently carefully cut off with a construction knife;
• In conclusion, the ends of the window sill are protected with plugs, and the window sill itself is cleaned of the protective film.

Such a window sill is fixed with a special mortar or glue, but you can also use screws on mechanical supports. In order for warm air to freely rise from the battery to the top, thereby drying the inside of the slopes and double-glazed windows when heating the room, the installation of a PVC window sill requires leaving a protrusion of up to 60 mm. In length, the plastic window sill should not exceed the width of the window opening by 15–20 cm. Inside the room, the protrusion of the window sill should be at least 5–7 cm wide. When installing a window sill of this type above a steam heating battery, as a rule, a slight gap is left.

Wood

Installing a wooden window sill is more difficult, so they have already begun to forget about well-fitted wooden boards, although they are not only no less aesthetic and beautiful than plastic, but also more environmentally friendly. To properly install this type of window sill, you will need to pay attention, first of all, to the source material. The window sill board must be free from defects (such as knots and other defects), and, in addition, well dried.

• The board is carefully cut off on each side,
• After that, it is given the desired look and, of course, a selection of teardrops and moulds is made. Under the teardrops are meant gutters 7-9 mm wide and 5-6 mm deep, located at the bottom of the window sill board at a distance of 2-3 cm from its front side;
• At the end of processing, the board is cut to the desired length, and it is given the desired shape. It is important to place all window boxes horizontally at the same level. By the way, it is also possible to create composite window sills connected with dowels, dowels and glue. The optimal length of the window sill is 10 - 15 cm more than the width of the window opening. And the optimal protrusion inward should be 5-8 cm less than the width of the window opening.

Do-it-yourself window sill installation in this case is done as follows:

• Work begins with the lower section of the board, which is placed on the wall. It is on it that the felt treated with antiseptics is attached, which, with the help of a shred, is attached to a board nailed;
• The prepared board is put on a quarter of the bottom beam of the box and fastened to the box with long nails, thereby fixing it even more reliably. At the same time, the nail heads are cut off and the cut off ends are driven into the lower part of the box bar, and then the window sill is planted on the ends of the protruding nails. If you have to deal with brick or stone walls, the window sill will have to be fixed using a lime-gypsum mortar. The window sill should deviate into the room by no more than 2 0. If its ends must be embedded in concrete or plaster, they must be treated with antiseptics.

To date, the market has a fairly large number of different window sills, which are made of plastic, wood and other materials. Installation of such structures by specialists will be expensive, because many people want to know how to properly install a window sill with their own hands.

How is a plastic window sill installed?

The plastic profile is an environmentally friendly material, and all structures that are made from it undergo careful control.

Such window sills have many advantages:

1. The structures are light in weight.
2. They are easy enough to install.
3. Such designs do not need to be painted.
4. Plastic products are impact resistant.
5. Resistant to heat and light.
6. Do not rot.
7. Products practically do not ignite.

Such structures can be installed even by a person who does not have the appropriate work experience, and special tools will not be needed. Plastic window sill can be installed on any window in the room or on the balcony.

To properly mount such a window sill with your own hands, you need to know the sequence of actions.

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Existing methods of installing a window sill

To install a plastic structure, it is necessary to measure the parameters of the window.

There are several options for installing such structures. In the first case, the window sill is fixed with a special compound. This method is outdated and rarely used today, as other, more modern and convenient mounting methods have appeared.

In order to be able to quickly, self-tapping screws should be used. In this case, it will be necessary to drill a hole in the frame into which the fasteners are installed. The joint should be treated with a silicone-based sealant. The extreme part of the window sill starts under the frame and is attracted by self-tapping screws. The rigidity of the structure can be given with special linings. The place under the window sill must be treated with mounting foam.

In the process of mounting such structures, metal spring clips can also be used. They should be screwed to the profile with self-tapping screws. The product is installed in the groove that is formed between the frame and the fastener.

The latter method will not use any extras such as screws or staples. This method is labor-intensive, but the most reliable. The principle of installation is that special linings are installed under the structure so that its edge fits snugly under the window frame.

The last 3 methods are used quite often. Each of them has its own advantages and disadvantages. For example, it is impossible to fasten a plastic window sill to self-tapping screws if the sash opens. All methods differ only in the way PVC window sills are inserted into the frame, all other stages of work are identical.

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How to do preparatory work?

The first step is to purchase all the necessary tools and materials. The quality of the work performed will depend on the quality of the tools used.

Items you will need:

1. PVC profiles.
2. Self-tapping screws.
3. Silicone sealant.
4. Mounting foam.
5. Spring clips made of metal.
6. Linings.
7. Simple pencil.
8. Building level.
9. Saw or electric jigsaw.
10. Metal strips.
11. Masking tape.
12. Polyurethane foam.
13. Nails.
14. Screws.

In order to correctly install the structure for PVC windows, measurements should be taken. Strength and how well the structure will cope with its functions depend on the measurements. If measurements are not taken correctly, the design will not have the best appearance.

You should know that it will not work to fix the installed window sill made of plastic or wood in case of incorrect measurements. In this case, all installation work will need to be done again.

In the process of measurements, it is necessary to take into account the properties and characteristics of the plastic, as well as a number of some other parameters. These parameters include the height of the batteries located under the windows. If the distance between the two structures is small, then the air circulation will be disturbed, as a result, the microclimate will deteriorate greatly.

When measuring the window sill to be installed, it is necessary to take into account the fact that its length should be several centimeters longer than the width of the window. The width of the structure can be chosen based on your own preferences, but the distance between the wall and the window sill should not be more than 8 cm. If the window sill is wide, this may affect the functions of the radiators. In the process of determining the dimensions of the structure, it is necessary to check the air circulation that forms in this area.

The products are installed close to the plastic window, therefore a special profile must be fixed on them, which will be used to fix the ebb.

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How to trim a window sill?

The design can be purchased ready-made or cut out of plastic yourself. If the window sill is cut out of PVC, then the profile must be purchased with a margin of about 5 cm.

The first step is to check the product for defects, as they can spoil the appearance. In some cases, it may be necessary to cut the structure to fit the size of the opening. To do this, first of all, you need to correctly mark the window sill. You can do this with a simple pencil.

The maximum length of the plastic structure is 3 m. The width of the product varies between 25-70 cm. If the width of the structure is too large, then the excess can be cut off from the part with which it is attached to the wall. Cut lines need to be given special attention. It should pass 0.5-1 cm behind the stiffeners, which are located inside the product. In this case, the window sill will be able to fit snugly into the window frame. The rear part of the structure should go under the window and be firmly supported by wedges and construction foam. If the extreme part of the product loses the stiffening ribs, then the inner base will not be able to maintain the necessary shape at the junction, as a result of which it will bend inward.

The window sill can be cut with a saw or an electric jigsaw. You can also use a hacksaw for plastic. You need to cut carefully, do not press hard on the tool so that scratches or other defects do not appear on the structure. Small pieces of plastic can get into your eyes. To avoid this, you should know the safety rules. You need to cut the plastic in goggles and work gloves.

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How to lay the lining?

To install the lining, bars should be used. They will take the load from the windowsill. If there are potholes or cracks, then you should use mounting foam. At this stage, it is important to check the fit of the product to the frame, as this indicator will guarantee the strength and reliability of the structure.

Slopes are installed. Their lower part must be cut down to the wall, after which the installation site must be cleaned of debris. The bars on which the window sill will be held should not go beyond the wall. Blades are best fixed immediately. Thus, it will be possible to form a groove into which the window structure will be installed. The window sill should be adjacent to the window frame. The gap between the structure and the walls should be less than 4 mm.

The part of the window sill that protrudes beyond the slopes should adjoin the wall tightly, since gaps are not allowed.

To prevent the structure from deforming, metal strips must be mounted under it. These products must fit into the bottom plug of the product.

Content:

• What is important to know before installing a window sill with your own hands
• Preparing to install a PVC window sill
• Video tutorial. Do-it-yourself PVC window sill installation

Photo 1 - Plastic window sill photo

Practical, attractive and inexpensive plastic window sills are most often installed together with the same windows, although other design solutions are possible. Installation of window sills does not require special skills, but you need to follow the technology exactly and perform all actions carefully.

The list of materials needed to install a PVC window sill

What you need to know in order for the installation of the window sill to be successful

Before starting any work, you need to carefully study the accompanying documents for all materials and tools used, if they have not been used before. This fully applies to the installation of a plastic window sill.

For example, it is very important to know at what temperature you can work with mounting foam. This information is on the product label. When choosing this material, you should give preference to products with the lowest coefficient of expansion, which will prevent the window sill from rising. The ideal option is to use a foam gun. In this case, as a rule, professional material is used, which does not expand significantly.

If you have to install a window sill in a window longer than 3 meters, then you will have to use additional parts that need to be carefully adjusted and glued, or special fillers for joints.

Preparing to install the window sill

In order for the window sill to serve for a long time, it is important to correctly determine its dimensions. The width is calculated taking into account the following components:

Window sill width :

• Desired indent from the inner surface of the wall. Experts do not recommend making it more than 15 cm, because it can become a hindrance. It is also important to consider the location of the heating devices. A window sill that is too wide can cause condensation to form on the side slopes and glass surfaces.
• Another 2 cm is added to enter the window sill under the window.

To determine the length you need to measure the window opening with a tape measure and add another 10 cm to this value. This is necessary so that the cut edges of the window sill are not visible.

Important!

After taking all the measurements, check them again. It is better to follow the rule: measure seven times, cut once. Thus, it will be possible to avoid annoying mistakes, which are quite difficult to correct, and sometimes impossible.

It remains only to cut off all unnecessary and you can proceed with the installation.

Video installation of PVC window sill. Main stages

First you need to clean the surface of the window opening from debris and dust. This must be done carefully so that the subsequent foaming is successful. The next step is to try on the window sill already prepared in size. If necessary, it is cut in the right places.

Photo 3 - Do-it-yourself PVC window sill installation

Next step- installation of a window sill. To do this, it is inserted into a special stand profile located under the window frame by 2 cm. Using a level, the surface of the window sill is exposed and wooden supports are substituted, which are necessary to ensure the calculated rigidity during the operation of the window sill.

The window sill is installed with a slight slope towards the inside of the room. This is necessary so that when condensation forms or watering flowers, excess moisture does not stagnate, but roll off the windowsill.

Photo 4 - Do-it-yourself PVC window sill installation

The next step is foaming. It is quite important, and it must be carried out with special care. Before proceeding directly to the process itself, the surface of the window opening must be moistened. This technique improves adhesion and more uniform distribution of the mounting foam.

First, the inner surface of the window sill and the junction with the staging profile are covered with foam. This avoids the appearance of such an unpleasant phenomenon as cold bridges.

Photo 5 - Do-it-yourself PVC window sill installation

After this operation, experts recommend installing a small load on the windowsill, which is removed after the foam has completely hardened.

Polyurethane foam is afraid of ultraviolet radiation, so you should not allow the sun's rays to fall on it. Even a thin layer of plaster or other material can protect it.

It remains to install the plug, cutting off the desired length from the workpiece and lubricate it with a cosmofen, press it to the ends of the window sill. And at the final stage, you need to remove the protective film and fill all the joints with silicone sealant, doing this very carefully.

Photo 6 - Do-it-yourself PVC window sill installation

From the foregoing, it becomes clear that even those who have a minimum of knowledge and skills in this area can cope with the installation of a plastic window sill. It is only important not to allow violations of technology and not to rush.

If the house has windows, then there must be window sills. A well-installed window sill performs not only a decorative function - it serves as a protection against the penetration of cold into the room.

Structures can be wood, granite or PVC. Do-it-yourself installation of a PVC window sill can be carried out only after studying the installation technology of PVC products.

1. Why PVC window sills
2. Preparing the installation site
3. General recommendations

Why PVC window sills

1. Unlike wooden window sills, PVC products perfectly withstand sudden changes in temperature.
2. High impact and scratch resistance.
3. Does not require anti-corrosion coating.
4. The presence of chambers provides good thermal insulation qualities.
5. Installation of the window sill can be carried out independently.
6. Easy care during operation.
7. PVC perfectly resists prolonged exposure to moisture.
8. Possibility of installation both for plastic, and for wooden designs of windows.

Selection of tools and material

Do-it-yourself high-quality installation of a plastic window sill can only be carried out with the right choice of source material, tools and the exact implementation of installation recommendations.

During installation you will need:

• Polyvinyl chloride window sill and plugs on its ends.
• Corner, building level, marker and tape measure.
• Silicone sealant and polyurethane foam.
• Electric jigsaw, puncher and screwdriver.
• cement mortar.
• Stationery knife and clean rags.

Preparing the installation site

A new PVC window sill will look good if you carefully prepare the place for its installation. This is especially important when replacing old windows. After dismantling the outdated window opening, the presence of chips and cracks around the window is checked. If necessary, the masonry should be restored. Remove small debris and dust, and apply a primer to the base.

Important! Before installing a PVC window sill, check the quality of the window frame installation to avoid cold penetration into the house.

When the new window is installed and the base for mounting the PVC window sill is carefully prepared, you can start measuring the space and preparing the window sill for installation. Before installing a plastic window sill, it will have to be cut to the width and length of the opening.

The width of the window sill can be the same as the slopes or a little more. In length, it is necessary to cut the product 4-6 cm more than the distance between the slopes. In the vertical slopes, two horizontal cuts are made, into which the window sill will be inserted.

Plastic window sills can be installed in three ways:

• Mounting foam or special glue is used to fix the product.
• The window sill is fixed with brackets.
• To install a PVC window sill, a profile is used.

Instructions for working with glue

Step #1. On the side slopes of the window opening, cut two notches at the same level, and clean the window sill well and, if necessary, deepen.

Step #2. Before installing a new window sill, dry and coat the surfaces with a primer.

Step #3. Insert the window sill cut to size into the grooves under the window frame.

Step number 4. Wedged the window sill between the frame and the window opening with wooden wedges. Insert wedges in the middle and edges of the window sill.

Important! There should be no gaps between the window sill and the window frame.

Step number 5. Between the window sill and the window opening, install linings so that the surface of the structure is horizontal.

Step number 6. Pump mounting foam with a small coefficient of expansion between the PVC window sill and the window opening. To prevent the window sill from rising, lay a load on top of it.

Step number 7. Install plugs on the side cuts.

Important! A window sill that strongly protrudes beyond the wall must be strengthened by applying cement mortar.

Step number 8. Remove the load 12 hours after foaming the window sill.

Rigid installation instructions

Such installation of a PVC window sill is considered the most durable and durable.

Step #1. Make the marking and trimming of the window sill, as in the previous installation option.

Step #2. On a previously cleaned window opening, perform a cement screed. Adjust the height of the screed so that the new window sill fits exactly into the grooves of the window frame.

Step #3. To fix the product, use liquid plastic or silicone glue.

Instructions for working with brackets

Step #1. A support profile is installed under the window and securely fastened. At least 4 brackets are mounted in it with self-tapping screws. The maximum distance between the brackets is 25 cm. Fastening is best done with self-tapping screws with press washers.

Step #2. The PVC window sill is being installed on the brackets. You should hear a click when properly seated.

Step #3. The window sill is connected to the frame with screws.

Step number 4. A wide window sill is additionally fixed to the cement mortar.

Instructions for working with a metal profile

Step #1. In a horizontal position, attach a L or U-shaped metal profile to the window sill block.

Step #2. Install the cut window sill into the groove and secure with self-tapping screws.

Step #3. Blow out the free space between the new structure and the base with foam.

Step number 4. Additionally, the structure can be strengthened with a cement mortar.

1. While working with a perforator, protect your hands with gloves and your eyes with special glasses.
2. Mounting foam adheres much better to a wetted surface. Before foaming, moisten the surface of the base and the back of the window sill with a spray bottle.
3. Sealant is best pumped in strips, leaving space between them.
4. The protrusion of the window sill beyond the window slope line should not be more than 60 mm, and the length should exceed the width of the window opening by a maximum of 15 cm.
5. If the window sill must be strictly horizontal along the length, then it is necessary to make a slight slope from the window along the width. The slope should not exceed 3%.
6. During the installation of window sills, it is necessary to take into account the location of the heating devices so as not to worsen the microclimate of the room.
7. The rigidity of the PVC window sill increases significantly when using a wooden backing. All bars must be the same size. The length of the bar is equal to the distance from the window frame to the edge of the opening. The distance between the fixed planks is 25 cm.
8. After complete hardening of the foam, its excess is removed. The wall under the windowsill is puttied and the decorating begins.

After reading the article to the end, you learned how to properly install a PVC window sill in several ways. Each mounting method has its advantages and disadvantages. With the right approach and high-quality performance, installing a new window sill is not as difficult as it seems at first glance.

Watch another video about installing a window sill. The owner of the apartment shares his installation experience.

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How to install window sills on plastic windows quickly and correctly

The inner window sill is an essential element of any window. It is officially considered that this part of the structure is necessary for additional insulation of the lower joint of the window frame with the wall and giving the window a finished look. In this article we will talk about what window sills are and, since plastic windows occupy at least 50 - 70% of the market, I will dwell on how to properly install a window sill on plastic windows.

What are window sills

By and large, if the craftsmen installed the window frame with high quality and foamed the bottom gap well, this sector no longer needs special insulation. Therefore, the owners are usually more interested in the question of how respectable this or that window sill will look, and of course the price of this pleasure.

Many inexperienced owners believe that since their windows are plastic, then the rest of the fittings must also be installed from PVC (polyvinyl chloride is popularly window plastic).

In fact, you can put any window sills here, the main thing is that they fit the design and you have enough money for them. Therefore, before putting a window sill on plastic windows, it will not be superfluous to familiarize yourself with the main offers on the market:

• Naturally, the most popular material is the above-mentioned polyvinyl chloride.. The hollow structure, reinforced with internal stiffeners, is considered to be quite warm and durable. With traditional white windows, it harmonizes almost perfectly, and for laminated windows, you can choose a window sill. Plus, a PVC plate costs quite reasonable money. Plastic is not afraid of moisture and, if the technology is not broken, then it will last as long as the windows;

If the choice fell on PVC, you should not get carried away with savings, they are not expensive anyway. The fact is that plastic, like no other material, is exposed to sunlight. While the window sill is new, everything will be beautiful, but after six months the surface of cheap plastic will change. It will at least turn yellow, and at the maximum it will crack and deform.

• Figuratively speaking, the older brother of polyvinyl chloride is an acrylic-based plastic window sill.. It costs about 3 times more expensive, but the quality here is much better. Whatever one may say, but PVC plate is afraid of high temperatures, unlike it, you can put hot pots on acrylic and even a cigarette butt forgotten on it will not harm the surface. Acrylic board is much stronger, its shiny glossy surface looks more respectable. The colors are brighter here, and the palette is wider;

• The wooden window sill is rightfully considered the patriarch of this trend.. In the public sector, as a rule, pine is used. The range of species in elite window sills is much wider, it can be golden oak, teak and a dozen more exotic types of wood. But to be honest, I do not understand people who put expensive natural wood on plastic windows. And in general, plastic does not harmonize well with wood, except if these windows are laminated to a certain type of wood;

• Window sills made of laminated chipboard or MDF are quite another matter.. In this case, the same plates come here, from which countertops are made, which designers actively use. Chipboard will cost a little less, MDF will come out more expensive. But MDF is more resistant to damp environments and I always recommend installing it. Since installing a window sill if the window is already there, the task for the home master is quite feasible, people are now massively rushing to change the old plastic to the new laminated MDF;

• A polished window sill made of natural stone certainly looks luxurious, but their prices are, frankly, exorbitant. Although if you look, in operation they are not so good. The fact is that natural stone is unpredictable, stains from coffee or red wine can remain on it, any plate always has a critical point, with a light blow to which the plate bursts. Plus, the same granite can often and densely emit a little radiation. Agree, it’s not pleasant enough to install such a “gift” in your own home, and even for a lot of money;

• Both in terms of cost and performance, it is much more profitable to install modern artificial stone. First, in appearance, it often does not differ from natural. Secondly, it is more resistant to mechanical and chemical stress. The reproaches of skeptics that artificial stone is less durable are only partly true. After all, for example, the guarantee for porcelain stoneware starts from 50 to 70 years. Roughly speaking, these window sills can get bored rather than fall apart.

For a story about manufacturers and prices for all existing types of window sills, no article is enough. But since even an amateur can correctly put a plastic window sill, I decided to focus on it. Plus, according to statistics, about 50% of the plastic window market is occupied by PVC window sills.

Below, in order to make it easier for you to navigate, I have compiled a small table that contains the most popular and reliable manufacturers of various window fittings with average prices for the window sills we are interested in.

Company name	Manufacturer country	Average price per linear meter of window sill	Types of design (except for white, it is everywhere)
Moeller	Germany	330 rub.
Werzalit	Germany	350 rub.
Niko-Plast	Russia	560 rub.
Danke	Ukraine	365 rub.	Imitation of natural stones and wood. 11 kinds
Melenger	Russia	960 rub.	Imitation of natural stones and wood. 12 kinds
crystalite	Russia	345 rub.	Imitation of natural stones and wood. 16 kinds
Montblanc	Russia	60 rub. (White) 130 rub. (color)	Imitation of natural stones and wood. 10 kinds
Vitrage	Russia	350 rub.	Imitation of natural stones and wood. 14 kinds

Window sill installation technique

The easiest way is to install or replace a window sill made of PVC and acrylic with your own hands. Installation instructions for MDF, chipboard and natural wood are not much more complicated. As for natural or artificial stone, it is better to entrust these materials to professionals, since not every master is able to install them.

Dismantling the old stove

Naturally, before replacing an old, obsolete window sill with a new one, you must first dismantle it. Do not be afraid, this is a simple matter, but responsible. After all, the more carefully you remove the stove, the less hassle will be with the preparation of the base.

• If there is a wooden window sill, then to dismantle it, you will need a hacksaw and a pry bar or a small crowbar. It’s not worth knocking out the board with a mount right away, you can severely damage the slopes and then you have to mess around with them. It is better to make 2 or 3 cuts and pull out the central part. At the same time, on the sides you will have small pieces walled up in slopes. These pieces must be carefully knocked out with several blows from the side, at the butt;

I am often asked if it is possible to replace a hacksaw with a grinder? So in no case should you do this. Remember, perhaps the largest number of injuries and injuries from an angle grinder is obtained precisely when trying to cut a tree with an angle grinder.

• But in the case of a reinforced concrete or stone slab, a grinder with a diamond disc will be exactly what you need. In this case, in addition to it, a weighty hammer or a small sledgehammer will also come in handy. First, the grinder makes several cuts, if possible through. After that, take a hammer and knock out all this “cutting” with blows from the bottom up. The remains are cleaned with a mount;

• Fastening a plastic window sill is considered one of the weakest. But before you remove such a plate, you should first dismantle the ebb (outer window sill) and check if our plastic is screwed with self-tapping screws from the outside. If they are there, then naturally they will need to be unscrewed. If there are none, then you just have to carefully cut the mounting foam under the slab and try to pull out the window sill, moving it down and towards you at the same time.

A few words about preparing the foundation

Whether you are changing an old design or working from scratch, before you mount anything new, you must definitely prepare the base. In fact, all preparation consists in cleaning up dust and debris, as well as puttying large potholes, if any.

Some masters advise to make an even screed under the window sill, supposedly on its basis it will be easier to level the slab. I tried to install both with and without a screed, on a bare base.

I'll tell you honestly, there is nothing reprehensible in the screed, you can do this, but it's a pity the time spent on it. Indeed, by and large, there is no difference in whether you put wooden wedges on a flat base or on a curve. And if you plan to install on alabaster or cement-sand mortar, the arrangement of an even screed generally loses its meaning.

Let's start installation

Installation of a window sill always begins with a fitting. Of course, ideally, it is better to install the window sill even before the slopes are arranged, while the walls are bare, but this happens only in new buildings.

Since we are talking about how to change the old to the new, we will have to cut, or rather, knock out grooves in the side slopes. There is one interesting nuance here. The instruction recommends that before placing the window sill to the plastic window, make wide lateral tolerances, approximately 5 - 7 cm from each edge.

That is, we need to make side grooves in the slopes with a depth of 5 - 7 cm along the outer edge. It is believed that this is allegedly more elegant. If you need to cultivate 1 - 2 windows, then these visits to the walls will not play a big role.

It is a completely different matter when the task is to fully equip all the windows in a fairly large private house, and funds are limited. In this case, an addition of 10 cm on each window, at the end, will result in a whole extra window sill.

Personally, I always recommend making lateral tolerances of no more than 20 - 30 mm. Believe me, this is quite enough to ensure a decent appearance. Moreover, curtains are hung on most windows in residential buildings and apartments, which will completely close all these tolerances.

The side grooves themselves are knocked out to the tolerance depth, that is, to the distance at which the plate will go inside the slope.

In order to accurately mark and not grab too much, you need to take a square, attach it to the window frame and draw a horizontal line starting from the upper cut of the groove under the window sill and ending with the outer cut of the slope. This will be the upper limit of our groove.

The easiest way is to make cuts on the slopes with a grinder to the desired depth, and then knock out the excess with a puncher or a chisel with a hammer.

Plastic window sills can be installed in two ways, with and without fixation on the window frame. The only difference is that in the first version, the inner end of the window sill, the one that is adjacent to the window frame, is first rigidly fixed on this very frame. Further, the entire installation algorithm is completely identical.

When marking and trimming the window sill, it should be noted that it should not protrude beyond the cut of the wall by more than 5 - 7 cm. And under the frame itself, the plane is immersed by a maximum of 1 - 2 cm.

Fixing on the frame is extremely simple. In the place where the window sill will be adjacent to the frame, in increments of 300 - 400 mm, a series of through holes is made along the horizon. After that, the window sill is pressed against the frame and from the side of the street, it is screwed through these holes with long self-tapping screws. Self-tapping screws must enter the body of the plate by at least 20 - 30 mm.

But it is not always possible to screw the plate with self-tapping screws to the frame. In this case, it is simply inserted under the frame. To enhance the thermal insulation, immediately before strengthening the slab, I apply a couple of strips of mounting foam to the place of its installation.

The installation of a plastic window sill itself looks something like this: first we insert the plate we cut out and see how it will lie in the future. There is no need to worry about the curvature along the horizon. After all, the plate is adjacent to the lower edge of the window frame, which is already set to the horizon.

But we need to slightly tilt the plate inside the room, so that if necessary, water does not accumulate, but flows freely from the windowsill. How much I have come across, in different sources, the value of this angle is interpreted differently. Personally, I make a slope in the region of 5 mm in width.

The inclined plate itself will be based on wooden wedges. These wedges are usually installed at a distance of about 300 mm from each other. Each of them is cut and adjusted individually and should fit snugly, without gaps.

As mentioned earlier, the plate sits in a groove under the window frame on the mounting foam. Then it rests on the wedges we installed. But before fixing it completely, check again that it stands firmly, without distortions and play. It is better to tinker with the fit of the wedges now than to constantly cover up the cracks later.

To increase the adhesion (adhesion) of the mounting foam with any surface, this very surface must be well moistened.

The slab is fastened by filling the voids under it with mounting foam. And do not try to blow out too much foam, it will not be better from this, because the excess will come out anyway.

As you know, the mounting foam expands when it hardens, and if this feature of it is not taken into account in time, then your window sill can be squeezed out in the middle. So that such an opportunity does not happen, after filling the gaps with foam, you need to put a load of about 15 - 20 kg on the windowsill. It should stand for at least 10 - 12 hours.

At the last stage, the load is removed, the excess foam squeezed out from below is cut off, and the hard-hitting cracks on the sides in the slopes are puttied. The only thing left to do is enjoy your work.

Installation of wood and its derivatives

As I already mentioned, installing window sills made of natural wood, MDF or chipboard is not a little more difficult than installing plastic. Here, in the same way, it is necessary, after marking, to knock out the grooves in the slopes.

The window sill itself, if the frame design allows, it is desirable to fix it on the frame or on the base profile, which is placed under the frame. As in the case of plastic, this is done using self-tapping screws, through through holes.

But in this case, there is one small nuance: there is such an interesting physical quantity as the coefficient of thermal expansion of the material. So, when we put a plastic window sill on a plastic window, there is nothing to be afraid of, because this coefficient is the same for them.

But in the case of joining different materials, as a result of a mismatch in thermal and moisture expansion, gaps and cracks may appear over time. Therefore, we will need to glue the so-called damper tape to the end of the plate, which is designed to compensate for these fluctuations.

Naturally, this tape is glued or attached to the brackets, only in places of direct contact with the body of the slopes and the window frame. Traditionally, the material for such a tape is felt impregnated with an antiseptic. Although now some craftsmen use penofol (polyethylene foam).

Wood, chipboard or MDF is heavier than plastic, so I personally prefer to use gypsum mortar instead of mounting foam, it's more reliable. Instead of gypsum, with the same success, you can install the slab on a cement-sand mortar, diluted in a ratio of 1: 3.

In this case, the instruction will look something like this. We knock out the grooves in the slopes, try on the slab and grind the required number of wooden wedges under it. After that, we apply the solution to the base. The solution layer should cover the wedges by 5-10 mm.

Further along the line of docking with the frame, we apply a couple of strips of mounting foam. We insert the window sill with a damper tape and press it until it rests on the wedges. We remove the excess of the squeezed out solution and putty the cracks on the slopes at the junction with the slab.

If everything is done correctly, then the window sill will stand firmly. But some masters prefer to play it safe. They hammer a long nail into wooden wedges from below in such a way that it passes through and looks out from above by 10 - 15 mm. The wooden wedge itself is fixed to the base with an anchor.

As a result, when you finally insert the slab, it sits on the nails sticking out of the wedges and fastens tightly. A worthy method.

The only downside here is that before installation, you need to carefully measure and check everything several times. Otherwise, in case of an error, almost everything will have to be done again, because the nails will no longer allow you to move or adjust the plate.

Conclusion

Now you know how to install a window sill on plastic windows. The photos and videos in this article provide additional information on this topic. If you have any questions, leave them in the comments, let's talk.