How to cover up polyurethane foam - effective and affordable ways. How to protect the polyurethane foam - the properties of the sealant itself and methods of its protection

Using polyurethane foam, we are able to completely eliminate all gaps after installing windows and doors. However, having cut off all the excess of this material, we are faced with the task of hiding the traces of the foam itself, since it looks rather unpresentable. Today we will reveal the features of this process and talk about how to solve the problem as quickly and efficiently as possible.

The chemical product is a polyurethane-based sealant containing isocyanate and polyol. This is the basis, however, different manufacturers may include various additives such as catalysts, stabilizers, blowing agents, and the like. The foam has high adhesion and expandability, allowing it to fill the entire space. The materials with which this foam forms the strongest bonds are as follows:

Cement;
Metal;
Plaster.

At the same time, plastic or greasy materials, as well as wet surfaces, adhere to such foam to a much lesser extent. This, in turn, ensures that we do not apply it in places where it should not be. Although, it is still not easy to wipe off such foam from such surfaces.

How to cut polyurethane foam

It is necessary to cut off the foam with a technical knife, which must be sharp. Try to cut in such a way that the remaining foam is flush with both surfaces on the sides of it. This will facilitate further processing.

Do I need to cut the polyurethane foam with a sealant?

Polyurethane foam is an excellent insulator, however, it itself needs insulation. If this is not done, the surface will begin to crack under the influence of solar radiation and moisture. Therefore, it is necessary to hide its cut so that the foam does not collapse ahead of time (usually its insulating properties are enough for 4 years). As a sealant, polyurethane can be used, as the most suitable for such a bond. Pre-compressed sealing tape is also widely used for sealing foam. However, you need to understand that construction tape is a very dubious decision from a design point of view. In addition, do not apply any finishing materials, since, after being saturated with them, the tape will begin to peel off.

Foam plaster and other finishes

In addition to the options listed above, the following are used:

Acrylic paint;
A mixture of cement, white grout and sand;
Putty. Finishing plaster is suitable, which has the ability to tolerate negative temperatures;
Window putty or liquid plastic.

Depending on the type of concealment polyurethane foam, it is necessary to carry out certain actions. For example, if the foam is painted over, then this can be done directly on even cut... However, in the case of plaster, it is necessary to first ensure a better adhesion to the surface. And for this, small grooves are cut in the foam.

The layer of plaster with which we will cover the foam should not be thin. Indeed, in this case, it will very quickly begin to crack and crumble. Try to keep the layer thickness at least three millimeters

Foam grouting is done in two cases:

Before painting, in order to create the most even surface. In this case, you need to ensure that the cut does not begin to collapse, and this requires the use of the finest sandpaper;
In the case of the application of plaster, after the latter has dried, the surface is carefully trowelled in order to give it an attractive appearance.

How to protect the polyurethane foam? In theory, this issue should not concern ordinary citizens, owners of houses and apartments. If the installation of windows and doors was carried out good specialists, then there will be no problems.

According to the theory (GOST 30971-2002 "About assembly seams… "), The inner surface of the seam will be protected by a moisture-resistant vapor-tight gasket. After all the work, the polyurethane foam will not stick out with inside, nor from the outside.

But very often you have to deal with foam protection issues yourself. Or the installers did not behave in good faith. Either we ourselves decided to suck new door without referring to specialists. And since we are not professionals, the foam after sealing can protrude far forward from all sides.

What do we protect polyurethane foam from?

Polyurethane foam is an excellent sealant. It firmly connects almost all building materials. You can foam concrete surfaces, block, brick, plastered, wooden, etc. Foam not only fills voids, but also protects the room from heat loss, performs waterproofing and soundproofing tasks.

But such quality of polyurethane foam as strength is fully manifested under certain conditions. More specifically, the foam is susceptible to rainfall, chemicals and ultraviolet rays. Under the influence of external factors, the assembly sealant rapidly loses its strength characteristics.

After three to four years, the unprotected foam begins to crumble and crumble. Voids and cracks form in the seam. And the polyurethane foam should "work" for more than a dozen years!

When the sealant dries, it turns slightly yellow. This is fine. But if the foam turns dark orange, yellow-brown, then the process of destruction is in full swing. You can check its stage by picking up the foam with a knife. In any case, with such a painting, it is recommended to completely remove the damaged sealant, and the seam to be repaired.

outside - from aggressive climatic troubles and ultraviolet radiation;
in the center - from low temperatures(insulation);
indoors - from condensation and steam.

Let's take a closer look.

1. In new buildings, to fill defects inside the opening, you can use PSUL (pre-compressed sealing tape). It is glued on window frame when installing.

2. For waterproofing joints and seams in old houses, a diffusion waterproofing tape is suitable. It has double-sided adhesive strips and functions like a membrane.

The waterproofing tape protects the foam from condensation inside the room and from moisture outside.

Both of these materials are glued before installing the windows and applying the foam.

3. Cured polyurethane foam can be protected by such means as:

plaster or putty (if the work is carried out outside, then the mixture must be frost-resistant);
cement-sand mortar with the addition of white grout;
polyurethane sealant;
liquid plastic;
acrylate coloring composition;
putty.

The safest option is to apply a putty followed by painting with an acrylate compound.

Briefly about the works themselves

If you decide to putty the seam and then paint, then the guide to action will look like this:

1. We are waiting for the complete drying of the polyurethane foam (at least eight to ten hours). We cut off its remains with a sharp assembly knife, going deep a couple of millimeters "into the seam".

2. The surface is cleaned of debris, primed.

3. When the primer is dry, apply a thin layer of putty. We are waiting for drying. Then - the finishing layer.

4. We clean the putty surface with sandpaper, prime and paint.

If you decide to paint the polyurethane foam right away, then cut off the excess sealant flush with the surface to be painted as carefully as possible. Then sand the surface with sandpaper. Remove all dust and debris. Apply acrylate paint.

Let's say that you are not going to be engaged in repairs yet. Then the foam can be protected with a good wide tape. Not very aesthetically pleasing and reliable, but it saves for two to three months. No more. Then you will have to take care of more reliable protection of the polyurethane foam.

There are cavities, for example, sockets filled with polyurethane foam. How to plaster them? What mixtures stick to polyurethane foam?

Very often, foam is used to seal joints when installing new plastic windows... In this case, the embedding procedure is somewhat different here. The foam is also cut off with a knife. Further, the joint filled with foam is sealed with a wide hydro and steam - insulating tape, with an adhesive and sticky layer. This tape has a layer of foil, therefore it also creates a heat-insulating screen. Now the entire joint, on both sides of the window, is covered from a sprayer with a primer, which contains an anti-fungal composition that prevents mold formation. And now, when the primer has dried, you can safely apply the plaster with a rubber trowel. Good producers, this is Ceresit, Knauf Rotband and Vetonit.

In general, it is desirable to seal the foam at the joint. To do this, apply a two-component sealant with a rubber spatula. Cooking working mixture the sealant by mixing the sealant and hardener with a drill (with a nozzle), and apply to the foam seam with a rubber spatula... Therefore, for external seams, and for seams in rooms with high humidity, better fit this method... In other cases, we plaster, also applying rubber spatula convenient width.

For plastering surfaces that are treated with polyurethane foam, you first need to cut off the protruding foam, then make small, one millimeter is enough, cuts along the entire continuation of the seam ...

Plastering can be done as in all other cases, nothing special ...

Polyurethane foam lends itself well to plastering, especially when you consider some of the nuances.

Before you start plastering the areas filled with polyurethane foam, you need to cut off the excess of the already dry material, and at that, slightly deepening the surface of the foam in relation to the sides. Surface cured foam try to align.

You can plaster the polyurethane foam with almost any composition (I will suggest Rotband, Forward KR +, etc. as an option), only it is worth using frost-resistant for outdoor work.

The sequence of work is approximately as follows:

dilute the dry mixture according to the instructions.
Apply with a spatula to the surface to be repaired (area with foam) with a transition to the base material of the wall and smooth. It should be noted that the plaster, thinly applied to the foam, will definitely crack when it dries, therefore the layer must be at least 3 mm.
after complete drying, we rub the surface with a mesh to obtain an even, smooth surface.

Yes, no problem, it can be plastered with anything, I don't understand your doubt, the foam is cut off flush with a knife, there, under the upper smooth crust, it is quite porous and any plaster will stick to it, even a simple cement mortar, but if you are in doubt and have a concern that in that place it will crack or break, then it will come to the rescue old proven method - alabaster, we clean it deeper, quickly knead it and quickly cover it up / plaster it. It dries up and hardens very quickly, then you can simply clean off the excess and uneven with a spatula and putty with a finishing putty, it will turn out cheap, angry and strong!

It is advisable to reinforce with a serpyanka.

Polyurethane foam is a polyurethane foam sealant used in construction. The material quickly hardens and protects the base from aggressive effects environment... However, the foam itself is vulnerable to external factors... A putty is used to protect the material. The main thing is to know how to choose and apply the composition.

The purpose of the foam is to fill in spaces and holes. The service life of the material after application is 5 years. After this period, the foam is removed and a new composition is used. If this is not done, then the material will collapse, and a favorable environment for the spread of mold and mildew will arise in the voids. In addition, polyurethane foam destroys ultraviolet radiation. To prevent this from happening, the material must be protected. This can be done in several ways:
Application of sealing tape. The material will protect the foam from UV rays and destruction, but the product has a short operational life and is not intended for outdoor use.
Application of a primer and similar formulations. The products provide waterproofing of the material, but do not protect from sunlight.
Puttying. The composition will protect the foam from moisture, ultraviolet radiation and other negative environmental influences. Professionals also highlight other advantages of the putty - affordable price and ease of use.
In addition, it is used acrylic paint, sealant, putty and other compounds, but such products will not provide reliable protection material if excess funds have to be trimmed.

How to protect the polyurethane foam?

How to putty the polyurethane foam - such a question arises for amateurs who first encountered such work. Any putty is suitable for this material. Professionals recommend choosing a composition based on where the material will be applied - indoors or outdoors. For this, a remedy for internal and external works, respectively.

Algorithm of work

If the repair is performed by a non-professional craftsman with his own hands, he is advised to carefully read the algorithm for applying the putty.

Choice of funds

As already mentioned, if the work is carried out indoors, then the composition for internal works, and if outside, then for the outside. In addition, the thickness of the layer of the product is taken into account. To disguise small defects and to protect the material, a thin layer of the composition is applied, 2 mm thick. For this, only putty is used. The variety doesn't matter. To fill voids, the depth of which is up to 15 cm, plaster is used before filling.
You will also need a primer. The composition improves the adhesion of the material and topcoat... Professionals advise using an acrylic primer. This composition is suitable for all types of surfaces and has good characteristics.

Putty tools

To carry out finishing work, you will need a set of tools, which includes:
stationery knife;
a set of spatulas for applying the product;
work gloves;
masking tape;
capacity and construction mixer(drill with mixer attachment) if dry mix is used.

Preparation of the building base

Surface preparation algorithm:
wait until the foam expands and hardens (the material dries up in 12 hours, but to clarify the time, it is recommended to carefully study the product packaging);
cut off the bulging edges with a clerical knife so that the surface becomes even (as in the photo below);
fix the masking tape to a surface that does not need rework;
fill the voids with plaster;
clean the base from dust and other contaminants;
apply primer.

Puttying

Putty on polyurethane foam is applied as follows:
Prepare the composition if a dry mixture is used for filling. Dilute the product with water. The amount of liquid for mixing the solution is indicated on the package.
Apply the product to the foam. Thickness - 3-5 mm.
When the composition hardens, clean the surface. Then primer the base.
Take a break to dry the primer. The hardening time is indicated on the packaging of the composition.
Apply finishing putty... Layer thickness - 1 mm. When the material hardens, sand it with fine sandpaper. Suitable material is P 120 or P 150. Then primer the surface. After the composition has dried, finish and remove the masking tape from the untreated surface.

Puttying window slopes

If you need to putty the window bevels, then the joints and putty will need additional protection, which will be provided by the paintable sealant.
treat the surface with putty;
dismantle the material from the seam 3-4 mm from the edge;
Fill the resulting void with sealant.

Putty car arch

Polyurethane foam is also used for car repairs. The material is filled with voids that are formed as a result of stripping rust. Most often, polyurethane foam is used when repairing an arch. The material also needs protection, which the putty can provide. In addition, the composition will level the surface. You can use any tool to putty your car arch. Professionals recommend using fiberglass material as a starter. For the topcoat, a multi-purpose agent is used or the surface can be filled with an aluminum-filled product. After the composition has solidified, the base is cleaned and primed. Next, paint is applied and the work is completed.

Calculation of the consumption of putty for polyurethane foam

The calculation of the consumption of putty per 1 sq. M of polyurethane foam is indicated on the package. Usually it is 0.6-1 kg per 1 m2 when applied in a layer with a thickness of 1 mm. Therefore, the thicker the layer, the more putty will be required. It is necessary to perform an accurate calculation of the funds, since the finished composition cannot be stored.

How much does a polyurethane foam putty cost?

If we talk about how much a putty for polyurethane foam costs, then it all depends on the product. For example, the price for a latex composition is 200 rubles per 1 kg. The dry mix is much cheaper. The price for 25 kg of funds is about 250 rubles. The cost of the putty also depends on the manufacturer. The more popular the brand, the higher the price of the product.
The video in this article demonstrates how to properly putty polyurethane foam.

Puttying polyurethane foam is a mandatory stage of repair before finishing. Neglect of such work will lead to the destruction of the material and the appearance of an aggressive bacterial environment.

There are cavities, for example, sockets filled with polyurethane foam. How to plaster them? What mixtures stick to polyurethane foam?

Very often, foam is used to seal joints when installing new plastic windows. In this case, the embedding procedure is somewhat different here. The foam is also cut off with a knife. Further, the joint filled with foam is sealed with a wide hydro and steam - insulating tape, with an adhesive and sticky layer. This tape has a layer of foil, therefore it also creates a heat-insulating screen. Now the entire joint, on both sides of the window, is covered from a sprayer with a primer, which contains an anti-fungal composition that prevents mold formation. And now, when the primer has dried, you can safely apply the plaster with a rubber trowel. Good producers are Ceresit, Knauf Rotband and Vetonit.

In general, it is desirable to seal the foam at the joint. To do this, apply a two-component sealant with a rubber spatula. Prepare the working mixture of the sealant by mixing the sealant and the hardener with a drill (with a nozzle), and apply to the foam seam with a rubber spatula... Therefore, for external seams, and for seams in rooms with high humidity, this method is better suited.

How and what to putty polyurethane foam in 3 stages

In other cases, we plaster, also using a rubber trowel of a convenient width.

Plastering can be done as in all other cases, nothing special ...

Polyurethane foam lends itself well to plastering, especially when you consider some of the nuances.

You can plaster the polyurethane foam with almost any composition (I will suggest Rotband, Forward KR +, etc. as an option), only it is worth using frost-resistant for outdoor work.

The sequence of work is approximately as follows:

dilute the dry mixture according to the instructions.
Apply with a spatula to the surface to be repaired (area with foam) with a transition to the base material of the wall and smooth. It should be noted that the plaster, thinly applied to the foam, will definitely crack when it dries, therefore the layer must be at least 3 mm.
after complete drying, we rub the surface with a mesh to obtain an even, smooth surface.

It is advisable to reinforce with a serpyanka.

Rules for working with polyurethane foam - all questions and answers

Review of foam-cement brand Macroflex

We use Macroflex construction foam so often that its name has already become a household name. The reason for this is high quality assembly compounds at a reasonable cost, a convenient form of release, designed for use in private construction, and unique properties... Let's try to evaluate the validity of the last point using the example of the new composition from Macroflex.

Characteristics and properties

According to numerous reviews, foam-cement works optimally at an ambient temperature of about +21 .. + 25 ° С, however, it can be used in the range of -5 .. + 35 ° С. Compared to standard assembly mixes, this means slightly more off-season work opportunities.

Main characteristics declared by the manufacturer.

(short-term up to +110 ° С)

The use of polyurethane foam with the addition of cement shows itself perfectly when gluing wooden structures, materials from woodworking products and some polymers:

the tensile adhesion to wood at Macroflex reaches 2 MPa, as in cement with granite;
with ABS plastic and PVC - about 1 MPa (the same adhesion is observed for cement mortar with concrete surfaces).

Medium adhesion strength (0.3 MPa) foam editing room Macroflex detects with concrete, glass, ceramics - that is, with materials whose structure does not differ in high porosity. Approximately the same firmly the composition binds to OSB boards... With bituminous coatings and foam, the adhesion of Macroflex is slightly worse than 0.2-0.25 MPa. This is the tile adhesive level.

The least reliable Macroflex turns out to be on galvanized, drywall, and mineral wool- 0.10-0.15 MPa with a layer of 8 mm. So with these materials, it can only be used in non-loadable structures.

Since the scope of application of Macroflex also includes outdoor work, the possibility of normal use of foam-cement when negative temperatures Is a very useful property.

Pros and cons of foam

The main advantage of any assembly mixture packed in a tube is its ease of use. Foam Macroflex is easily applied with a gun, which allows you to control the amount of the squeezed out composition, avoiding overruns. The cementitious adhesive at the place of application reliably insulates the joints from moisture and significantly reduces heat loss.

The disadvantages of any polyurethane foam are usually large shrinkage... But foam-cement initially has a small volume of expansion, so it does not "shrink" so noticeably. But another disadvantage follows from the high density - the high consumption of the composition.

The cost of cement glue does not differ from the price of ordinary polyurethane foam - 370-390 rubles per 850 ml.

Construction adhesive-foam of the Macroflex brand allows in some cases to refuse heavy cement mortars when performing repair and construction operations:

Erection of light lintels and restoration of block masonry.
Thermal insulation and finishing of surfaces with slab materials.
Installation of window sills, frames, staircase elements.
Elimination of gaps, strengthening and insulation of seams.

The consumption of glue depends on building material that you will have to work with. According to reviews, it takes one standard 850 ml cylinder to complete 10 m 2 of brickwork. The same amount will be required for gluing gypsum panels with a total area of up to 12 m 2.

Application building mixture allowed on any wet materials except foam concrete.

REDUCE CONSUMPTION up to 50%!
Everyone needs to know this!

Application for different types works

Brick or block masonry.

The composition is applied to the glued surfaces of each block in two continuous strips with an indent from the edge of 30-50 mm.

If the masonry is half a brick wide, you can do with one strip of Macroflex cement in the center. Brickwork with the help of foam, it is performed only on a leveled surface so that there are no vertical distortions in the rows. If this is not the case, you need to lay the usual one on the foundation. building mixture thick and set the correct level for the first row.

Professional foam Macroflex, although it belongs to construction workers, for masonry responsible load-bearing walls not good. Its main purpose is the construction of internal partitions and the installation of small architectural structures.

On a relatively flat surface, drywall is faster and easier to glue than to assemble a complex crate under it. The glue is applied to the inside of the gypsum board over the entire area in strips - a step of 150 mm, an indent from the edge of 50 mm.

Polyurethane foam and plaster - how to make them friends?

You need to do everything at a pace, because after 3 minutes, if you do not put the sheet in place, the surface of the foam-cement will stop sticking.

Once Macroflex is applied, the sheet is applied to the prepared wall surface and easily pressed down. You need to hold the panel for 5 minutes, after which you can move on to the next one. Grouting and others Finishing work can be done 2 hours after gluing.

Installation of window sills, steps.

On the fixing part of the window sill, squeeze out 2-3 strips of Macroflex along the edge. Press it against the end surface of the wall, loading it along its entire length for an hour. Make sure that the window sill is clearly level. The installation of individual prefabricated steps is carried out according to the same principle. flights of stairs from any materials.