How to coat the joints of plastic windows

Choosing a sealant for windows - an overview of types

When installing new plastic structures, installers often poorly seal the joints in the areas where windows meet slopes, window sills meet windows, or do not seal them at all. And most window companies do not install slopes at all, so homeowners make slopes without the help of others. And then it becomes necessary to seal the cracks with one of the sealing compounds. For this purpose, it is best to use sealant for plastic windows. It is used to seal slopes made of plastic panels and is also used to fill voids between the frame and the window sill.

We insulate windows for the winter - goals and purposes

The issue of insulating windows for the winter can still be solved today using old-fashioned methods, for example, sealing the cracks with paper, tape or strips of old newspapers, stuffing them with cotton wool or rags. Practical, but not at all aesthetically pleasing - this option is unlikely to suit the owner of an apartment where renovation has just been completed. Modern window sealants make it possible to insulate windows completely unnoticed - strips of sealant become part of the window, merge with it, in some cases they can be painted or you can choose a transparent, colorless option.

Modern window sealants

Some sealants are used at the window installation stage - polyurethane foam wedges the window well and fills all the voids in the walls, and is perfectly hidden under a layer of plaster or PVC or metal slopes. Others can be used immediately before the onset of cold weather, sealing cracks at the windowsill and at the junction with the wall. It should be understood that one single window sealant will not solve the problem of insulation and sound insulation - you need to use several materials in combination, for indoor and outdoor use. Before going to the construction market, decide what goals you are pursuing. Window sealant can be:

frost-resistant
fireproof
for outdoor use
for sealing seams and cracks indoors
elastic
for painting
transparent
with pigment
UV resistant

Elastic sealant for windows

None of the existing sealants combines all these qualities. However, they are all in one bottle and are not needed. Thus, frost resistance is important for external sealants, transparency is important for sealing seams in large panoramic windows, resistance to ultraviolet radiation is useful only if the seams are not hidden under a protective layer of paint or plaster. Let's take a closer look at the existing proposals.

Cracks on slopes - causes and repair of defects - Blog Stroyremontiruy

If cracks appear on the window slopes, then you should not get out of the situation by covering the problem with curtains, because even small cracks can cause drafts and heat loss in the apartment. Cracks on slopes do not appear out of nowhere, so before eliminating them, determine the cause of the damage and then repair the defects in the optimal way.

Causes of cracks

The causes of cracks on window slopes are different, but are classified into several main groups:

Improper installation of windows, drywall or application of plaster,
Unstable house foundation
Low quality finishing materials,
Violation of window operation.

If cracks between the slope and the frame appeared after installing the window, when the craftsmen were installing gypsum boards or doing plaster, then do not try to fix them yourself. Take a warranty on the work and call the experts to correct the errors. If you fix the cracks yourself, but nothing good comes of it, then no one will redo the work for free.

If the foundation “floats”, then cracks appear not only on the slopes - defects occupy the walls and, occasionally, the ceiling. This is a serious problem, so there is no talk of craftsmen here - contact the operating company or the contractor directly (personal cottage).

Poor quality material also leads to the appearance of cracks and even peeling from the base of the plaster or drywall. The main reason for the low quality of glue, plaster mixture or putty is its improper storage. When purchasing material, please note that all dry mixtures must be stored on pallets, and you cannot sell the material on the street in rain or frost.

Also, strong physical exertion when closing a window leads to the appearance of cracks - the shutters should not be slammed hard, showing masculine strength, since this will cause even a well-installed double-glazed window to vibrate and cracks will crawl like cockroaches.

Drywall

If the cause of the cracks is not the foundation or the installation of the window, then you can repair the defects yourself. Small cracks in drywall are protected with a rough abrasive cloth until plaster is applied, after which the surface:

Primed,
Seal with two layers of putty,
Grind with fine abrasive
Re-prime and paint.

If there are many cracks, but they are small, then you will have to glue fiberglass, which will take on the functions of reinforcement. To do this, the base is cleaned, primed, glued with Bostik glue or an analogue for fiberglass web, putty again, sanded and painted over. The work is labor-intensive, but there will be no defects for years.

Large cracks can be caused by detachment of the gypsum board from the base. Corrected by complete dismantling of drywall and reinstallation of gypsum boards with a full range of subsequent finishing. Don’t forget about fiberglass, if time is running out and you don’t have it at hand, then glue the gypsum board seams with reinforcing tape - this is a must.

Plaster

Cracks in the plaster of slopes can be small or large. Small cracks just need to be puttyed and painted over again; large defects require complete or partial dismantling of the plaster.

Before starting sealing, to accurately determine the causes of cracks, tap the slope. If the sound is dull, it means there are voids and the plaster will have to be knocked down. After this, the solution must be applied in 2-3 layers, allowing it to dry. The last layer is rubbed with a float or a metal spatula (depending on the type of plaster), the slope is allowed to dry and a standard paint finish is applied (putty, cobweb, primer, paint).

If the plaster was knocked down, then the perforated corner must also be rearranged. When redecorating plasterboard slopes, a corner is left.

Repair materials

For gluing fiberglass, we recommend the classics - Bostik glue or Cover acrylic composition for fiberglass. An alternative to Oscar glue, which is sold ready for use.

For indoor slopes, there is no need to buy facade putty - the putty mixture Acrylic Puts, Typhoon Master or Ceresit for interior work is suitable. It is better to buy “start+finish” mixtures, as they are used for the first and second layers. Dry putty is cheaper, so buy it. For drywall, 1-1.5 kg of dry mixture is enough per window; for plaster, the consumption is higher - up to 3 kg per window.

We seal from the inside - acrylic and butyl sealants

Sealing window seams with butyl sealants often occurs already at the stage of assembling double-glazed windows at the time of production. Butyl compounds are based on a mixture of polyisobutylene and ordinary chalk. Chalk acts as a filler, and the quality of the sealant depends on its quantity. The best ratio is considered to be 50 to 50, but many manufacturers prefer to save on the more expensive polyisobutylene. Unfortunately for many consumers, the characteristics of the purchase can only be assessed some time after it has been applied and cured. Compositions with too much chalk quickly dry out, crack and crumble.

Butyl sealants are used exclusively for sealing work indoors. When choosing a composition, pay attention to the components from which it is made - if the label also indicates paraffin or industrial oil, then such a sealant will have much better adhesion to different materials.

Butyl window sealant

Another type of sealant for interior work is acrylic. This type is characterized by low vapor permeability, and therefore it is often used to protect polyurethane foam from moisture and condensation. Acrylic compounds adhere perfectly to any surface, even if they are not completely dry. The main disadvantage of acrylic sealants is their low elasticity. In frosty weather they become completely hard and may crack. Therefore, sealing window seams from the outside with such compounds does not justify itself at all. The advantages include the fact that acrylic seams can be painted in any color with almost any paint. Therefore, most of these sealants are sold in white.

Butyl tapes are not the same thing as butyl sealants. Butyl rubber is used as a polymer base in the tapes, as well as a number of plasticizers and fillers. The quality of the finished product depends on them, so butyl tapes should be purchased with great care so as not to end up with a completely unsuitable sealant. Paraffin and industrial oil are also used as a plasticizer to improve material adhesion.

When working with butyl compounds, it is important to very carefully remove any remaining dirt, paint and old putty. It doesn’t hurt to coat the areas where the seam will go with a special primer. Using acrylic sealants, you can do without any primers.

Application area of sealant

This substance is a paste containing polymer compounds. There are several types of sealant, differing in composition and characteristics, but they have the same basic properties: plastic when extruded, they harden in air, creating a reliable heat-insulating and moisture-proof layer. The seam, made using white sealant, is invisible against the background of the slopes and the frame of the double-glazed window.

These qualities, complemented by good adhesion to different surfaces, have made sealants indispensable for sealing cracks formed after the installation of plastic windows.

Sealants for external use – exploring offers

Silicone compounds have been and remain among the most affordable and most popular sealants for sealing joints outside. Most often you can find white window sealant on sale - this is due to the color of PVC windows, often also white. However, silicone is actually colorless, and clear versions can also be found commercially. The most important advantage of this sealant is its high elasticity, which is maintained even at very low temperatures. In addition, silicone sealant is not afraid of moisture and ultraviolet radiation, which makes it suitable for insulating windows for the winter.

The main component of such compounds is rubber, which feels great on any surface. Since it is completely safe, silicone sealant is often used for interior work. However, when purchasing it, you should either select the desired color in advance, or not paint the seams in the future, since the paint adheres very poorly to silicone and does not adhere well after drying. The highest quality is considered to be an acidic silicone seal, which is easily recognized by the smell of vinegar. However, such compositions are incompatible with metal surfaces.

Exterior sealant

When buying window sealant, choose one that contains fungicides, in this case you will avoid the appearance of mold on the seams.

Silicone sealant has a serious drawback - “musicality”. The point is that when the composition is applied to the seam between the glass and the frame, it forms a thin film. After some time, this film can peel off from the glass, and then the windows begin to whistle in unison with the gusts of wind, in the most literal sense of the word. Whistling can only be eliminated by sealing the seam with a new layer of sealant after removing the old one. By the way, it is sometimes removed completely by accident, you just have to pull the hanging threads of the thin film.

Silicone sealant for windows

Among the new products on the market are acrylic silicone sealants, which combine the qualities of acrylic and silicone. Such sealants are highly elastic and at the same time can be painted. However, they also cost more. If a high level of sealing of seams and surfaces is most important to you, then the best choice is thiokol sealant. They are based on polysulfide oligomers - a component that provides a high degree of fluidity and viscosity after hardening. The high cost of thiokol compounds is justified by very powerful sealing. Working with them is quite difficult, since you have to mix two components yourself, so they are often used only by professionals.

Related article: Window sealant for plastic windows

Do-it-yourself grouting and sealing of windows

Grouting of joints on window openings is usually done by specialists immediately after the installation of PVC structures. However, sometimes you have to do this on your own, because not everyone resorts to the help of workers. Many people install windows or slopes without contacting builders, so in such cases they also have to grout the seams without unnecessary help.

In addition, after several years, the old material loses its properties, so the cracks will have to be processed again. But first, it’s worth understanding the types of compounds that serve such purposes and analyzing their qualities that are suitable for a particular case.

Types of materials and results

Liquid plastic

Liquid plastic is most often used to fill cracks and seams between the frame, slopes and window sill. This composition is widely used among professionals. Available in a tube or as a cartridge for a pistol. The color of liquid plastic can be white or transparent.

The kit usually includes a special nozzle that allows you to apply the strip into the seam as thinly as possible. One of the well-known brands that produce these materials is Cosmofen.

After drying, the mass becomes hard, resembling plastic.

Silicone sealant

Silicone sealant is also a means for grouting joints, but many reject its candidacy because of its elasticity. In fact, softness after drying will not affect the performance in any way, so you can safely use it.

By the way, after several years of service, such material can be easily removed from the surface of the window sill and slope panels. This line of products has many shades, so this material is perfect for the owner of textured and colored windows.

Acrylic sealant

Acrylic sealant also has a wide color palette, but the classic white color is also available in almost every store. After drying, it becomes more rigid, but not as hard as liquid plastic. It has a lower percentage of elasticity, but this is its advantage for many buyers. You can also use this product, but it is better to choose from sanitary representatives with special additives. Well-known and high-quality sealants: “Tytan”, “VGT”, “Makroflex”, “Moment”, etc.

Adhesive/cold welding

Adhesive/cold welding can also be used to seal seams on window units, but their properties differ from sealing materials. These compounds glue one part to another, which eliminates the possibility of their easy replacement if they lose their properties after some time. At the same time, the slope panels may be slightly deformed when the cold weld dries, despite the fact that it was originally intended for PVC; this occurs due to the strong adhesion, given that the panel and frame are perpendicular to each other, creating an angle of 90 degrees.

You can purchase any of the above products, but the results will be different, so you must initially decide which product is more suitable in a particular case.

Preparation and application of sealing material

It doesn’t matter what grout material is chosen, in any case you need to prepare the following:

sealant or liquid plastic;
container with water;
a towel or piece of fabric (rags - BUT! clean);
degreaser;
latex gloves (optional);
gun.

Sealing the seams of plastic windows: nuances, protection, sealants

Sealing the seams of plastic windows: nuances, protection, sealants Call a specialist (Moscow and Moscow region): +7 499 3504609
Window repairPrices

Installed windows and forgot? It doesn’t always work out this way, especially when the installation was done by inexperienced craftsmen. There are often cases when it seems that the installation work has just been carried out and the window seams are already required to be sealed.

Why might additional window sealing be required? What are the reasons? And what to do with it? We will try to answer these questions in the material presented.

Acrylic sealants for sealing the installation seam of windows according to GOST

Let's consider the advantages of sealants for insulating a heat-insulating layer.

Advantages of sealants relative to mounting tapes:

A more hermetically sealed application means you don’t have to level the opening in advance and don’t have to wait for it to dry. Due to their liquid consistency, sealants fill cracks, irregularities and voids in the opening during the application of the external seam.
Higher water resistance - in order for water to begin to penetrate through the sealant layer, a pressure drop of more than 600 Pa is required (this happens, for example, with a wind of more than 30 m/s). Through the joint of the tape with a wall or window, water begins to leak at 150 Pa, i.e. already with a wind of 17 m/s.
Higher seam protection against blowing. A 2mm layer of sealant can withstand hurricane winds at a speed of 45m/s for at least 3 hours without blowing. No ribbon can withstand such wind.

Photo: the tape does not have a tight connection with the opening and the product; additional sealing is required

Sealant can be used to cover an installation gap of any width, and the range of external sealing tapes is limited to several sizes (10, 12, 15, 20mm, less often 50mm)
High maintainability – a damaged area of sealant can be easily restored; you don’t even have to remove the old one. The damaged tape will have to be replaced completely, which may entail a complete reinstallation of the window and slopes.
More affordable price relative to high-quality tapes.

Disadvantages of sealants compared to tapes:

In winter, installation will take two days: to apply the sealant, you need to wait until the foam hardens. In winter, this happens for several hours, so processing the seam will have to be postponed until the next day.
Applying sealant takes longer than applying tape - approximately 15-20 minutes, including protecting the window with masking tape.
It cannot be used when repairing an assembly seam when the window is already installed and requires repair.

According to industry experts in the field of installation, sealants today occupy about 60% of the market, due to the optimal price-quality ratio.

How to seal and why do it?

Have you found a gap between the wall and the window? Urgently contact the Teplo Doma company for help. It will only get worse: draft, condensation, mold, slope destruction.

What material is required to successfully seal the seams of plastic windows? Today, for these purposes, as a rule, one-component polyurethane, or in other words, polyurethane foam, is used. This method has a lot of undeniable advantages:

The foam evenly fills the gap and does not let air through.
Capable of carrying quite heavy loads.
Has excellent thermal insulation characteristics.
It's inexpensive.
She's easy to work with.

There are many building materials, but none can compete with polyurethane foam in this matter.

Of course, working with foam is convenient and profitable, but there are also negative aspects. Illiterate use of this material can lead to extremely unpleasant moments. For example, you knew that polyurethane should never be left in the sun, because it is destroyed by ultraviolet rays. You probably heard it. But some developers probably have no idea that polyurethane foam needs to be protected. This is evidenced by open seams between plastic windows and openings on the facades of new buildings.

After the polyurethane foam has dried, you need to trim off the excess, and then cover it with putty and paint. Let's not forget that one-component polyurethane absorbs water well, so it definitely needs a protective layer. There may also be a sealant for exterior use. Only in this way can high-quality external sealing of the window be carried out.

It is worth noting that dried foam can change in volume under the influence of temperatures. One-component polyurethane can expand by 5-10% in hot weather, and vice versa shrink in cold weather. As a result, the metal-plastic structure will “walk” along the opening. This must be taken into account during installation. You still have a question: where did the cracks come from? Incorrect installation is to blame.

If you encounter such a problem, contact the Teplo Doma specialists right now. Our craftsmen will be happy to repair your windows and eliminate the draft.

To eliminate the problem, it is necessary to clean out the old foam, then a new sealing of the installation seam is required, and then the one-component polyurethane should be protected from the sun and precipitation.

Gaps between frame and slopes

These elements are in contact with each other, and the tightness of the structure as a whole depends on these joints.

The main causes of defects are:

violation of installation rules - uneven alignment, deviation of elements from the overall structure due to compression or expansion under the influence of temperatures;
poor sealing of the space between the wall and the frame - it should be remembered that the foam is not resistant to the sun, humidity from the street, so it needs to be puttied and painted;
no gap for thermal expansion or zero installation gap.

If a crack appears, but there is no opportunity to invite a specialist, then you can make the repair yourself. You will need tools, materials, and instructions. The most effective repair methods in this situation are:

A temporary measure is sealing without dismantling the structure. This action is considered temporary, since the main cause cannot be identified. The defect is simply masked.
A reliable and durable method is to disassemble the structure and identify the causes. But only professionals can do this.

How to seal seams?

In fact, if the polyurethane foam was applied correctly, then the windows do not require additional sealing. But if there is a need for this, then this event will help to apply the sealant. As a rule, it has good adhesion to most materials, does not allow moisture to pass through, and is able to protect the foam. Sealant for sealing windows can be used for both interior and exterior work. What sealants are suitable?

Silicone.
Rubber.
Acrylic.
Thiokol.
Acrylate.
Polysulfide.
Polyurethane.
Acetate.

What is the result? First, the window is installed ( it is desirable that the distance from the wall to the frame does not exceed 2 centimeters

).
Next, the seams are filled with polyurethane foam ( if work takes place in winter, it is necessary to use a special one-component polyurethane for work at subzero temperatures
). When the foam dries, you need to cut off the excess. Next, the joints are sealed with sealant, plastered, puttied, and painted. Then the ebb, window sill, external and internal slopes can be installed.

Is it possible to seal a PVC window if the frame is cracked? If the structure itself is damaged, it must be replaced. Otherwise, it will not be possible to achieve high-quality sealing.

Is it possible to seal windows from the outside if the glass unit is cracked? Damaged glass unit needs to be replaced. It is impossible to achieve its sealing at home.

Thiokol (polysulfide) sealant

A two-component composition with good viscosity and fluidity. Easy to use, penetrates into the smallest cracks and seals them. By adding different amounts of hardener, you can adjust the rate of hardening from several hours to several days. Professionals prefer to use it at the junction of tides. It is allowed to use thiokol sealant at sub-zero temperatures, which allows work to be carried out in the cold season.

Advantages of thiokol composition:

lasting;
resistant to chemically active substances;
not afraid of sunlight, high and low temperatures (operating range - from -50 °C to +130 °C);
has low moisture and vapor permeability.

USEFUL INFORMATION: How to install a plastic window sill with your own hands
The only drawback is the high price.

Which sealant to choose?

Many people are interested in the question, which polymer is better for sealing windows? There are three most common and accessible options:

Acrylic sealant.
Silicone sealant.
Acrylate sealant.

First option

Quite easy to apply. It is inexpensive and universal in use, reliable and safe. In addition, acrylic sealant is suitable for wood. But when it hardens, this composition is not very elastic. We have already said that a window can “walk” in the opening. And if it moves too much, the sealant layer may burst. I would also like to note that acrylic sealant shrinks slightly, so when working with it you should think about applying the material in two layers.

Second option

Ideal for sealing seams. Silicone sealant is not afraid of moisture and is able to thoroughly seal the seam between the frame and the window sill, between the frame and the slope. When the composition dries, it has good elasticity, which in our case is a huge plus. Silicone sealant has excellent adhesion to most materials. As for the weaknesses, this sealant cannot be painted.

Third option

Ideal for sealing the external joint between the frame and the wall. Acrylate sealant is not afraid of weather conditions. A seam made of this material easily resists precipitation and exposure to ultraviolet rays. Acrylate sealants can create a seam that will last more than 20 years. The sealant can be worked at temperatures of -10 degrees; it has amazing adhesion to all materials. After the composition has dried, putty can be applied on top and then painted. Acrylate sealant works equally well on dry and wet surfaces.

Polymer sealant (liquid plastic)

It consists of dissolved PVC granules. Indistinguishable from the material of a window block, it combines a plastic slope with a frame into a monolithic structure. It is more expensive than silicone-based analogues. The most popular brand is Cocmofen.

Advantages of liquid plastic:

easy to apply;
hardens quickly;
lasts 15 years without changing color;
safe;
resistant to ultraviolet radiation and other atmospheric influences.

Minuses:

does not tolerate tensile or compressive loads (after hardening, the composition does not have elasticity);
Suitable only for plastic slopes.

Choosing sealant for windows - overview of types

When installing new plastic structures, installers often poorly seal the joints where windows meet slopes, window sills meet windows, or do not seal them at all. And most window companies do not install slopes at all, so homeowners make slopes themselves. Then the need arises to seal the cracks with one of the sealing compounds. For this purpose, it is best to use sealant for plastic windows. It is used to seal slopes made of plastic panels, and is also used to fill voids between the frame and the window sill.

Related article: How plastic windows are regulated

Slope options

There are several ways to finish slopes:

Plastering the opening. This type of slope finishing is the most common and cheapest. To do it, first of all you need to prime the surface, after which you need to apply a layer of putty to the slopes, which needs to be smoothed evenly. When the slopes are completely dry, you can decorate the slopes, that is, rub them down to a smooth surface, and then paint them.
Making slopes from plasterboard slabs. To perform such a finish, it is necessary to make a metal frame around the window on the slopes, after which they are covered with plasterboard boards. Upon completion, it is necessary to putty the surface and decorate it.
Finishing slopes with plastic panels. The most modern method of finishing slopes, which in the future does not cause such problems as the occurrence of cracks between the frame and the slope.

Thus, the most optimal option for finishing slopes is to use plastic panels. This is explained by:

The surface of the slopes will be of the same type, and they will look harmonious with plastic windows.
There is no risk of cracks occurring in the slope of a plastic window , which is most important after the crack appears and its repair.
Plastic panels allow you to additionally insulate the slope, which prevents it from freezing. This prevents the formation of condensation and moisture accumulation, and as a result, mold and mildew will not form on the window.
Plastic panels are easy to maintain and do not require painting. It is enough to wipe them from dust, just like a plastic window.

Types of window sealants, their features

There are quite a few types of sealants, so let’s try to figure out which sealant is best for PVC plastic windows. Below we will look at the main types of sealing compounds that can be used to seal cracks in plastic structures. We will pay special attention to their adhesive and strength properties.

Silicone

This is a universal composition created on the basis of organosilicon compounds. It can be used both indoors and outdoors . It is characterized by elasticity, high adhesive qualities, ease of application and affordable cost. It is divided into acidic and neutral types. When using an acid sealant, a vinegar smell appears in the room, which subsequently disappears. Silicone does not shrink, does not lose its color and elasticity.

Tip: It is recommended to use sanitary silicone sealant for plastic windows indoors. It is resistant to the formation of mold and all kinds of fungi, so it always retains its whiteness.

Acrylic

Also elastic, in a liquid state it is washed off with water. It is used primarily for outdoor work , for sealing installation joints, as it is resistant to ultraviolet radiation and precipitation. It is not used so widely for interior work, since the porous structure of the hardened sealant over time begins to absorb all kinds of fumes from the home and as a result the sealed layer can gradually darken. To prevent darkening, it is recommended to paint it. Acrylic sealant for plastic windows for winter for external use has a low cost.

PVC-based sealant (polymer)

It is based on MS polymers. It is also called liquid plastic. Has excellent adhesion and viscosity . After sealing the cracks of plastic windows, it forms a single structure with this material. The only requirement for the use of this type of sealant is the absence of any type of load on the seams that could lead to rupture of the hardened material. The price for such white polymer window sealant is quite high, which is based on its high-tech properties.

Polymer sealant Cosmofen

Polyurethane sealant

This viscous material based on polyurethane polymers easily adheres to almost all materials, including PVC. After hardening, it can be painted or coated with a layer of varnish.

Butyl sealant

They are made on the basis of polyisobutylene (a rubber-like substance). It retains its elasticity and firmness in the temperature range from -55 to +100 degrees. UV resistant, harmless to others. It is used not only for sealing cracks, but also for repairing double-glazed windows , as it has high vapor permeability.

Theocol sealant

It is made on the basis of polysulfide components. This composition allows theocol window sealant to harden regardless of air temperature and humidity. It is indispensable for outdoor work . In practice, this means that such a composition can be confidently used in winter, as well as in rainy weather.

From the above list, silicone, butyl and polymer sealants have the best properties for indoor use at an affordable price.

How to seal a gap in a plastic window

One of the most vulnerable places in the house, where heat loss most often occurs, is the windows. Of course, it is impossible to provide ideal heat and noise insulation in this place, but everyone can reduce the noise level and heat loss to a minimum. The thing is that the cause of increased noise and heat loss is the cracks in the windows.

To do this, you should use a sealant. But often gaps in PVC windows arise because the rubber seal has worn out, then you just need to replace it with a new one.

You just need to remove the worn material from the grooves, clean them of dust, and then put a new seal in them. To increase its service life, it is necessary to apply silicone spray to it once a year.

The same sealant is used to cover the cracks in wooden windows. It is better to replace rotten glazing beads on such windows first. It is also good to seal the gaps formed between the sashes and the frame (or glass and frame) with synthetic adhesive tape.

Installation errors lead to a large number of problems. To avoid them, you should initially contact experienced specialists.

Remove the old foam layer.
Clean the gap thoroughly.
Blow out new foam.
Wait until it dries.
Trim off the excess.
Caulk the joints.
Paint it.
Additionally, seal the cracks with acrylic frost-resistant sealant.

This is about the question of how to cover up the cracks in plastic windows from the outside. Of course, if you do not have experience in carrying out repair work, then it is better to seek help from specialists.

What sealant should I use to seal (coat) cracks in plastic windows? You can use acrylic, bitumen or polyurethane sealant. The main thing is not to use silicone sealant; under the influence of temperatures it can roll up and become unusable.

Silicone sealant is the most widely used.

Advantages: Color almost does not change with age. Doesn't shrink. Very elastic. Affordable in price. Disadvantages: Most silicone sealants smell like vinegar during installation. The silicone is spread over the surface with a thin film, almost imperceptible. Over time, it begins to peel off and hangs in such rags.

When you try to remove them, the entire seam follows them. The most disgusting feature of silicone is that between the frames and the slope, when the wind blows, the sealant film also sometimes hums and whistles in unison with the wind. It is the “whistle of the window” that customers complain about, and so many calls sometimes happen precisely for such a seemingly frivolous reason!

Acrylic is rarely used now

Advantages: odorless. Also elastic. It's easy to put away when needed. Disadvantages: Almost immediately it attracts dust, collects all the dirt, and soon turns gray.

The most common synthetic is Quilosa.

Advantages: No smell. It can be removed with water for some time after application; this is convenient for redoing, if necessary. It hardens like glue, but retains elasticity. Cleans well, even with a sponge, does not peel off. The seams are not blown through. Disadvantages: When drying, it shrinks somewhat. Therefore, you go through large seams twice. It turns slightly yellow with use. Not sold in every store.

How to seal cracks in plastic windows

We found out which putty is best to use for exterior and interior work. Now we will describe in detail how modern plastic windows are sealed. You will not encounter any particular difficulties when performing this operation.

If plastic slopes are already installed, stock up with construction tape, a sponge, a special syringe for window putty, napkins and any convenient container into which you will pour water.

Prepare PVC slopes and frames for the upcoming procedure. Clean them from dust and dirt to increase the adhesion coefficient of the plastic. Place tape along the edges of the gaps. With its help, after completing the work, you can easily remove the remaining putty. However, the use of tape is optional. Decide for yourself whether you need it or not.
Dissolve the silicone sealant, draw it into a syringe, and point the tool at an acute angle into the gap. Squeeze out the composition. The nose of the syringe will immediately smooth out the assembly seam (but only if you hold it strictly at an acute angle).
Excess putty that appears on the surface of the gap should be carefully smoothed with your finger, after moistening it in water. Here it is important to distribute the sealant as evenly as possible along the seam. There should not be even the smallest voids left.
Use a napkin to wipe the putty off your finger. Take a sponge, wet it, and carefully remove excess sealant from the surface of the seam. Perform the operation very carefully. The laid layer of putty must not be damaged. Rinse the sponge in a container of water frequently. Then it will not cling to the main layer of the assembly seam.

Advice.
Seal window openings in stages. Treat one small area first. Remove the mastic from it. Then move on to the next section. The putty hardens fairly quickly. If you immediately fill a gap that is large in length and area, you may not have time to properly level the composition. The final work is to clean the slope and window frame from putty. Remove the tape, if you used it, and remove any remaining sealant. A small nuance: degreasing and cleaning window openings cannot be carried out with acetone solutions.

They leave clearly visible streaks and stains on PVC structures. It is recommended to clean slopes and frames with white spirit.

Sealant for window seams

The modern construction market offers a huge variety of all kinds of materials used for repairs and similar activities. This also applies to sealants for plastic (PVC) window products. Such compositions are understood as a plastic paste-like mixture created on the basis of certain polymers.

Any sealant for window seams hardens when applied to the surface being treated, resulting in a special moisture-resistant and airtight layer being formed. The latter reliably protects plastic structures from temperature changes and atmospheric influences, and gives the windows an attractive appearance.

silicone;
polymer;
acrylic (acrylate);
butyl;
polyurethane;
thiokolov.

All of these compositions can be used for sealing slopes, various gaps remaining on window (PVC and conventional wooden) structures after installation work, for additional noise and waterproofing.

At the same time, different types of sealants are characterized by their own strength indicators, adhesive and other performance properties. Let's try to figure out which mixtures are optimal for working with plastic windows.

Sealing compounds for external use

Acrylic mixtures are in most cases used to refine installation joints located outside the room. It is not advisable to use them for interior work. Sealing windows with acrylic sealant protects PVC products from the harmful effects of rain and snow, as well as ultraviolet radiation.

The compositions that interest us in their frozen form have a porous structure. For this reason, they are not used indoors. The porous surface at the seams easily absorbs fumes coming from living quarters. After some time, the acrylic putty begins to darken and lose its sealing properties.

Butyl sealant is also used to seal external seams. It is a rubber-like composition, made of polyisobutylene, and is characterized by high elasticity and elasticity. Such mixtures are absolutely safe for human health.

They have increased resistance to solar radiation and can be used at extreme temperatures (from +100 to –55 °C). An important advantage of butyl compositions is almost one hundred percent vapor permeability. This allows them to be used not only for sealing wooden and PVC frames, but also for restoring double-glazed windows.

Thiokol mixtures are created on the basis of polysulfide special compounds. Due to this, the sealant is able to harden in any weather conditions. It is guaranteed to set at high humidity, low temperature. Most often, thiokol compounds are used in cases where cracks are sealed in rainy weather or in winter.

Polyurethane sealant has approximately similar properties. It adheres to any substrate without any problems. They seal seams between wooden and metal-plastic frames. If desired, the polyurethane mixture (strictly after it has completely hardened) can be varnished or painted in any desired shade.

What sealant for external seams can be called the best? It all depends on what time of year the gaps are sealed and the slopes are improved, and what special requirements are put forward for the installation composition. If work is carried out in autumn or winter, it is advisable to use thiokol, polyurethane compounds.

In areas with large temperature differences, it is recommended to use butyl sealants. Acrylic mixtures allow you to minimize the financial costs of sealing external seams.

Polymer and silicone putties - ideal for internal use

Indoors, theoretically, any of the sealants described above can be used. But often this is simply not necessary. You will overpay for features that are absolutely unnecessary. To seal window gaps inside apartments and houses (and partly for insulation), it is wiser to choose a polymer or silicone sealant.

The first of these is often called liquid white plastic, since it is made on the basis of PVC polymers and is characterized by high viscosity and excellent adhesion to plastic products. This composition, after filling the gaps, creates a monolithic structure with the window.

It should be noted that white sealant based on polymer substances cannot be used in situations where any serious load is placed on the assembly seams. The composition does not have sufficient strength.

In such cases, there is a high probability of seam rupture. Another disadvantage of polymer putties is their high cost. It is completely justified. The sealant has truly high-tech characteristics. It can't be cheap.

White silicone window sealant is more affordable and yet effective in use. It is made from organosilicon components, which give the finished product excellent adhesive capabilities and high elasticity.

This putty does not change its color during use (remains white even 10 years after treatment) and does not shrink. Working with silicone for window openings is very simple.

Any home craftsman can seal seams with its help. The silicone-based composition is easy to apply, hardens well and quickly. Minimum problems and guaranteed results of waterproofing and sealing seams.

Please note that there are two types of silicone - neutral and acidic. There is no significant difference between these compositions. Acid sealant for PVC windows emits a barely perceptible smell of table vinegar after use.

This scent dissipates fairly quickly. The neutral silicone composition for plastic structures and wooden window frames has no foreign odors.

White sealant for plastic windows, which is better?

Within a few years after installing PVC windows, home owners begin to notice that the initially white stripes of sealant have acquired a gray or yellowish color. Problems can also arise after washing the windows - the stripes begin to flake and sag in completely undecorative flaps, which, moreover, are very difficult to remove with your own hands.

However, not all sealing compounds have such qualities. It’s just that most consumers, and even builders, do not know an alternative to the already familiar “silicone”. This is where we will begin the review. Silicone sealants are the most widespread and affordable. After hardening, the strip does not shrink and retains its elasticity and color for many years.

The unpleasant smell quickly disappears during installation, but this is not the only drawback. When installing PVC windows, very often invisible films form on the glass, which over time peel off and hang in rags. Don't try to tear them off - you can remove the entire seam with your own hands.

But this is not the worst thing - if between the surfaces (window frame and slope, frame and glass) during the installation or assembly of the PVC window, gaps were left through which the wind can penetrate, with strong gusts the window will begin to “whistle”, hum and howl. So if strange sounds appear in your house, this is not the ghost of a deceased great-grandmother at all, but just a window.

However, you need to understand that a mistake was made during the installation or assembly of the PVC window, and this problem must be solved in these directions. You also need to remember that not all types of silicone sealants can be painted. Sealing plastic windows with acrylic sealants yourself will cost almost the same as in the previous case.

The problem with acrylic compositions is color change. White due to dust and dirt can turn into gray in just a few days. Therefore, if you use acrylic sealant, it is to seal seams and cracks that are hidden from view, and to seal the gaps between the window opening and the frame.

This product has low vapor permeability, so it is ideal for protecting polyurethane foam from moisture. When used, the acrylic composition produces virtually no odor.

Sealing cracks in PVC structures

We figured out what sealant to use to seal cracks in plastic windows. Next, we'll look at how to do it correctly. It is assumed that PVC slopes have already been installed. Before starting work, you should prepare a syringe for sealant, a container of water, a sponge, a napkin and construction tape.

Sealing seams on PVC windows with sealant

The operating procedure will be as follows:

The surfaces of plastic frames and slopes are prepared for sealing with a sealing compound. It is recommended to stick construction tape to these surfaces along the edge of the gap, which will remove the remaining sealant, but you don’t have to use it;

Tip: Before sealing, clean the cracks from dirt, remnants of protective film, old sealant, and dust. This will significantly enhance adhesion in these areas.

Using a syringe, the window sealant is squeezed into the existing cracks. It is recommended to hold the syringe at an acute angle and guide it so that with its nose it simultaneously smoothes the seam;
The protruding layer of the compound should be smoothed with a wet finger, ensuring its uniform distribution over the entire area of the seam. You need to make sure that all seam voids are filled. The sealant is removed from the finger with a napkin;
Remains of sealant are removed with a damp sponge. This is done very carefully so as not to damage the laid layer of material. The sponge should be washed in a container of water as often as possible;
It is better to carry out the work in stages, in small sections. Let's say you apply sealant to one joint, then level it, and then remove the remaining sealant. If this is not done, the applied composition may begin to harden, and it will no longer be possible to level it;
The surfaces of the frame and slopes must be completely cleaned of sealant residues, as careless cleaning will leave unsightly marks on the white plastic. They will be invisible right away, but will later appear as dirty spots.

Tip: If the surface of the window sill, frame or slopes needs to be cleaned or degreased, do not use acetone-based solvents for this. Such a solvent will leave stains and stains on the surface of the plastic. It is best to use white spirit or gasoline solvent for this purpose.

Cracked sash: how to fix?

At this stage, we kindly ask you to call a specialist. After all, this is how you can save time, money and effort. In addition, you are guaranteed to receive fully functioning windows. Our master will inspect the structure, study the problem and offer the optimal solution.

What can you do if there is a crack in the corner of the window? The first step is to drill out the beginning of the crack so that it does not grow in the future. Next, you should use sandpaper to remove dirt and sand the surface. Afterwards, the problem area should be degreased. Then use a product like Cosmofen - this is liquid plastic. Finally polish and paint the surface. If everything is done correctly, the window will look like new.

Description of sealant Stiz A

One of the popular compounds for sealing PVC structures is Stiz A - a sealant for plastic windows made on the basis of acrylic. This is a one-component, vapor-permeable composition, completely ready for use. It is used for external work (Stiz B is used for internal work) associated with the installation of metal-plastic structures.

Using Stiz A sealant:

Sealant Stiz A in different containers

sealing the contact points of plastic windows to concrete or brick walls;
sealing cracks in frames;
filling installation joints around the perimeter of plastic windows;
filling voids in structures made of metal, wood, concrete, brick, natural and artificial stone.

Features of Stiz A:

high adhesion to any materials, including wet surfaces;
sealant for seams on windows is resistant to moisture, wind, and UV radiation;
has high vapor permeability;
After drying, the sealant can be painted or plastered;
applied with a spatula, brush, special gun or other device.

Characteristics of Steez A:

shrinkage during operation - no more than 20%;
temperature range for application –25 +35 degrees;
operating temperature –60 +80 degrees;
sealant consumption - 120 g per linear meter;
hardening time - 2 days;
service life - 20 years;
White color;
price - 800-900 rubles for 7 kg and about 90 rubles for 0.44 kg.

External and internal sealing of installed windows

Korovin Sergey Dmitrievich

Related article: Which roof windows are better

Master of Architecture, graduated from Samara State University of Architecture and Civil Engineering. 11 years of experience in design and construction.

Successful window installation is only part of the installation process, since the heat concentration inside the room and the optimal level of comfort directly depend on the quality of the structure’s sealing. In addition to practical indicators, the external design of the window opening will also noticeably change. The ability to properly seal windows after installation will not only eliminate the penetration of cold air from the street, but will also eliminate the formation of fungi, mold and the unpleasant smell of dampness.

Preparation for external sealing

It is necessary to seal the slopes both from the inside and from the outside in order to avoid the disastrous consequences of defects. When exposed to environmental factors, the polyurethane foam layer will undergo destruction and quickly lose its functionality. For this reason, external work is given priority attention and only after its completion is it taken up for interior decoration .

The finishing serves as protection for the polyurethane foam from destruction and an aesthetic appearance.

Before you begin installation, you need to decide on the materials that will become the basis of the slope. Plastic panels or the plaster method are often used as external elements. Similar materials are also used for interior work, where the choice expands significantly, including sandwich panels, wood or plasterboard.

After installing the window unit, all cracks and gaps are carefully sealed with foam.

Before sealing the window, all empty spaces must be carefully filled with foam. After this, waterproofing materials are applied and the structure is allowed to dry and settle. Before you begin sealing work, put the installed structure in order and treat it with antifungal drugs that are used during installation.

Covering windows with plaster

The plastering method is widespread among both experienced specialists and non-professional craftsmen. The popularity of plastering finishing is explained by the low cost of consumables and good quality compared to other methods. There is also a small disadvantage to this type of finishing, which is a large time investment. To get truly good results, craftsmen will have to sacrifice some time. However, labor costs will result in a successful completion.

Plastering of external slopes is carried out in 3 stages

By average standards, plastering work on external slopes will take from 2 to 3 days, since each of the applied layers of the mixture must dry well before applying the next one. The first and second layers must be made with a thermal insulation compound, which can be purchased in every specialized store . The layer is very important for maintaining heat in the house, which is especially important for regions with low temperatures. The third layer - the last - is applied with a regular plaster mixture. As soon as the sealed slopes have dried, you can safely sand and paint the surface in the desired colors.

Seal with plastic

Finishing slopes with plastic materials will be an excellent option for achieving quick results of decent quality. Universal plastic will help to cover small defects or errors made during installation of the structure. Plastic slopes can be freely purchased in almost every hardware store with a wide selection of colors. True, they will cost more than plaster.

Plastic panels are installed quickly and easily

To install such a panel, you first need to adjust it by cutting it to the required dimensions and attach it with mounting adhesive, and fill the joints with silicone sealant. Simple installation does not require knowledge of specialized skills, and the panels themselves have a long service life and do not require special care.

Features of sealing window openings

After installing plastic windows, the slopes are sealed inside and outside the room. The influence of environmental factors negatively affects the foam layer: it becomes deformed and loses its protective abilities. External work is carried out simultaneously with internal work.

Regardless of the material used, all surfaces around the window unit are additionally treated with special antifungal compounds.

It is imperative to use a material with the maximum percentage of waterproofing. It is recommended to lay sealing tape or a plastic equivalent 4 cm thick along the outer zones of the installation seam.

We seal the internal slopes

The interior decoration of windows needs to be given great attention, since not only the level of comfort and reliable protection from the external environment, but also the aesthetic component will depend on the quality of workmanship. Try to carry out the work with great care so that the result pleases you with a presentable appearance.

Application of drywall

This material is one of the most affordable price options that meets environmental requirements. It does an excellent job of retaining heat indoors and looks attractive from the outside. The disadvantage will be difficulty in installation, since the formed joints will have to be sealed especially carefully. The installed drywall must be puttied and painted. When choosing this material as a finish, give preference to moisture-resistant types. Before fixing the sheets, it is advisable to make a layer of glass wool to increase the thermal insulation properties .

Installing drywall is a labor-intensive and complex process.

Sandwich panels for embedding

Sandwich panels consist of two sheets of PVC, the filling of which contains polyurethane foam with a high thermal insulation function. The material has an increased level of comfort with excellent heat retention. Installation of sandwich panels is carried out using profiles, under which isover is laid. The technology is in many ways reminiscent of installing plastic slopes and is simple to implement. The thickness of the structure is 10 mm, and the material itself has a long service life.

Sandwich panels have high thermal insulation properties

Plastic option

The demand for plastic sealing is explained by its harmonious design due to the ability to choose the same color and structure of materials similar to the color scheme of the window opening. The panel is easily placed on a special glue, but first the surface must be laid out with isover. Upon completion of the work, carefully seal the openings with silicone sealant.

Characteristics

This sealant is a polymer material based on solvent and liquid PVC.

A lot of time has passed since the launch of liquid plastic production. Since then, the recipe has been changed in order to improve it, and today it has reached its maximum quality.

An ideal tool for sealing seams and gluing various structures simply cannot be found. The joints of the parts are connected using the diffuse welding method. After hardening, the glued elements become a single whole.

Ideal bonding occurs with:

polycarbonate;
organic glass;
hard plastic;
polyvinyl chloride;
polyethylene terephthalate;
rigid PVC with aluminum profiles and sealing;

Liquid plastic also stands out for its chemical resistance. Even the slightest change in shade is absolutely excluded.

It has such useful properties as:

Resistance to sub-zero temperatures.
Low thermal conductivity.
High level of resistance to external aggressive factors.

Characteristics of adhesive-sealant:

Working with liquid plastic at a humidity of 60-70% is most effective.
The sealant loses its adhesive properties after 60 seconds.
When applying liquid plastic, the room temperature should not exceed 20 degrees and fall below +5°C.
The recommended sealant consumption is 150 grams per square meter.
Reaching temperatures above 300 degrees, the glue can ignite.
Setting occurs after two to three minutes. Complete hardening occurs after 24 hours.

Despite such serious characteristics of the glue, it should be noted that it also has a number of limitations:

The structure of the parts to be glued must under no circumstances be porous. Surfaces with different thermal expansions should be glued with extreme care.

It is not recommended to glue parts that are in prolonged contact with water due to the lack of a positive result. When connecting surfaces made of aluminum materials, special treatment must be performed.

If there is a need to obtain a plastic seam, then adhesive-sealant, alas, is not suitable for the job. The low quality of diffuse welding can be influenced by the chemical inertness of polypropylene and A-PET.