Blowing from plastic windows: how to identify and eliminate the causes of drafts

Customers of plastic windows rightly expect from window systems absolute tightness and a uniformly tight rebate. However, profile structures often allow cold air from the street into the room. It happens that there is no draft, but the window blows cold. The cooled air moves downwards towards the warm air going up according to the law of convection. This effect is especially pronounced in large blind openings.

It is possible to provide a sufficiently dense vestibule from the 1st to the 5th floor. But on the 20th floor and above, the wind moves at a speed of more than 25 m/s, blowing through even blind systems. Cold air penetrates through the seal, causing the formation of condensation, ice, and freezing of windows. From this article you will learn how to find a place for blowing in a plastic window in order to reduce the cooling of the room and correct annoying defects.

Blowing from plastic windows - how to eliminate the cause?

By installing PVC windows in the house, the owners expect that they will solve the problem of drafts and heat loss forever (at least for 20-30 years). The advertisement convinced them of this. When the promised tightness of window structures, noise and heat insulation was enough for only a few months or years, a feeling of deception arises and the question arises - what to do?

Objectively assess the situation - how long has passed since the installation, whether the warranty is still valid.
Determine exactly where it is blowing from, from which area of the window.
Understand the cause of depressurization.
Find a way to eliminate it.

Ease of use

Let's consider the main advantages of plastic windows in terms of operation and protection of housing from negative influences. The main advantages are:

The windows do not sweat or freeze, maintaining visibility even at temperatures below minus 40 degrees.
It is possible to reduce heat loss in a separate room to 40-60 percent.
High noise insulation from the street side.
Impact resistance, vibration resistance, high light transmission.

PVC windows have a huge number of advantages - high noise insulation, high light conductivity, do not freeze, and can reduce heat loss by 40-60%

About 40% of the heat is lost precisely because of the gaps formed due to the deformation of the old window structure or as a result of shortcomings of the builders, due to the frame being unsuitable for the non-standard size of the opening, etc. Therefore, installing a plastic window will allow you to forget about regular concerns about insulating the premises, purchasing additional heaters and other measures to increase the temperature.

How to determine where exactly it is blowing from

Most often, cold air enters the room through:

Areas where the sashes adhere to the frame;
Glass contours;
Butt seams in the area of slopes and window sills;
The lower area under the window sill.

A quick way to find a weak spot is to use a thermal imager. How to check if it is blowing from a window if such a device is not at hand? A regular candle (wax, paraffin) or lighter will help. It needs to be lit and “bypassed” all areas of the window through which it can blow. The flickering of the fire will show exactly where the air from the street enters the house.

If you couldn’t find a “hole”, perhaps there really isn’t one. The feeling of a draft can be created by convective air currents. They occur during the cold season due to the large temperature difference between indoors and outdoors. The cold glass of the window cools the air in the house, it falls down and spreads throughout the room. At the same time, there is a feeling that it is blowing from the window.

If it didn’t seem like it to you and there is still a draft through the plastic window, and you even determined where exactly the cold air found a loophole, you need to understand why this happened.

Sash adjustment

Required after the new house has settled, when the window is difficult to close and open. The problem can be solved by adjusting the sash up and down. The adjustment holes are on the bottom hinge, open the window and remove the decorative strip. On the hinge there are two adjustment holes for a hex key, the top one, when turning the hex clockwise, raises the sash up or down.

The bottom hole adjusts the position to the right or left, turning it clockwise will move the sash to the left, counterclockwise - to the right.

Reasons for blowing plastic windows

By determining the exact location of the blowing, you can figure out why it is blowing from a plastic window.

It shows through the contour of the sash.

A draft usually appears due to incorrect pressure adjustment. The reason may be an incorrectly set mode. For example, in winter the summer mode is set, in which the sash pressure is weaker. Blowing can also occur due to sagging sash. Over time, this happens to almost every window. Therefore, it is important to carry out regular window maintenance.

It blows in the area where the sash is pressed against the impost.

In most cases, this is caused by a manufacturing defect or deformation of the impost.

Blows around the perimeter of the glass.

The seal is to blame. This part of the window structure lasts less than all the others. If the seal is not properly cared for, it becomes unusable within 2-3 years. Low quality material and even less.

Air enters from the hinge side.

This usually happens due to a mismatch between the locking elements and the mounting holes. In this case, the pressure density upon contact is weak.

The cold comes from the junction of the frame and the side wall and/or window sill.

The reason is poor-quality window installation. The craftsmen who installed the structure did not seal the joints properly or used low-quality materials for sealing. If the window is installed skewed, over time, cracks may appear in well-sealed seams.

It blows from under the windowsill.

This means that during the installation the master cheated and did not seal the space under the window sill tightly. The cracks could also form over time due to the poor quality of the materials used to install the window sill.

Blows from the handle of a plastic window.

This is usually observed in old PVC windows installed 10 or more years ago. The cause of the blowing is loose handle fittings. If there is a draft in this area on a new window, there is probably a defect in the fittings.

Stages of repair work

Remove the plastic protection from the slopes and completely remove the old insulating layer until a technological gap forms between the double-glazed window and the wall.
The surface must be cleaned of dust and primed with an antiseptic compound; this will improve adhesion to the foam that needs to be used to fill the gap.
Trim off the excess foam and begin insulation. The best material for this purpose would be mineral wool or penoplex. But it is worth remembering that mineral wool only works with a layer 10 cm thick and when installing it, a vapor barrier membrane is required that protects the material from moisture. It’s easier with penoplex; cut pieces of the required size and glue them with glue or “liquid nails” onto the surface of the slope; for reliability, you can additionally secure the material with self-tapping screws.
A plastic or metal corner is attached to the corners around the perimeter of the window, the entire surface is covered with a layer of plaster and primed. Only after all these stages can you decorate the slopes with plastic, metal or wood, depending on the type of facade finishing.
Small cracks are sealed with waterproof sealant; using a special gun this can be done simply and accurately.

All these repairs can be done independently, without any special skills and with a minimum set of tools that are found in every home.

Blowing from plastic windows - what to do?

They found the place where the air was blown, identified the problem, and all that remained was to fix it. Let us warn you right away - not all causes can be eliminated on your own. In some cases, you will have to completely dismantle the window. But, let's take it in order.

What to do if there is blowing from the frame of a plastic window in the sealing area:

Install a new seal (choose the one that suits your window);
Twice a year, when the seasons change, treat with special means. This will extend the service life by 2-3 times.

You can eliminate the blowing around the perimeter of the sash by adjusting the clamping force and/or eliminating the sagging of the sash.

To do this, you need to transfer it from the universal position to the winter position. The universal mode is installed by default when installing a window. Often craftsmen forget to tell the owners about the possibility of changing it. You can watch how to adjust the windows yourself if the sash is sagging in videos, of which there are a lot on the Internet. However, there is a nuance - there are several types of window structures and each has its own adjustment subtleties. Without knowledge of the design and experience working with it, the fittings can be broken. Window repair in this case will cost several times more than the sash adjustment service.

Is the air coming from the joint between the frame and the wall or window sill?

If the reason is a crack that has formed, it is enough to fill it with sealant. If it is blowing because the window was installed unevenly, you will have to dismantle and reinstall it.

If it blows in the area of the impost,

The window will most likely have to be replaced. Repairing a window structure with replacing the impost is usually not practical. If the window is still under warranty (hence, it was recently installed), immediately contact the seller and demand a free replacement.

Blowing in the area of the handle and hinges can be eliminated only by adjusting the fittings or replacing them.

In both cases, it is better to invite a specialist. Without the necessary skills, it is difficult to determine exactly what is broken and select the appropriate part.

If it blows from under the windows, or rather, from under the window sills,

you need to find the cracks, fill them with insulating material and additionally insulate the area under the window sill. In the worst case, if sealing the gap and insulation did not help, the window sill will have to be removed and reinstalled.

Blowing from under the glass bead

- a rather rare situation, but it also happens. It can be solved by replacing the rubber seal that seals the connection between the frame and the glass unit, or by installing new glazing beads if they are damaged.

Replacing the rubber seal

Before starting work, buy sealing tape and construction silicone adhesive; it is better to purchase consumables in specialized stores. The old rubber cord can be easily removed from the window profile; just pull it in the middle.

The grooves must be cleaned of dust and dirt, washed and degreased. We coat the grooves on the window with glue and carefully, without pulling, insert the seal around the perimeter of the window, cut off the excess and glue it.

Additionally, you can glue a seal with an adhesive strip to the sash; it will last no more than a year, but will protect the main tape from dirt and dust.

Should you fix window leaks yourself or call a professional?

We have given examples of the most common causes of drafts from plastic windows, which, with experience, can be quickly eliminated. But these are not all possible problems. There are often situations when owners have tried all the ways to get rid of the draft, following advice from the Internet, but they have not been able to eliminate the draft. This happens because without skills it is difficult to accurately determine the cause of depressurization. And the “scientific poking method” in this case can only worsen the situation.

An experienced technician will quickly find a “hole” in your window protection, determine the reason for its appearance and tell you what and how to do to make the window ventilate more. Our specialists always have the necessary fittings on hand if you need to change any of its elements, devices and tools to troubleshoot window structures. By contacting us, you save time and receive high-quality window repair services.

Cleaning and replacing accessories

Often the window begins to show through due to the fittings becoming clogged with dirt and dust; removing and washing the parts is indispensable. The entire window mechanism is attached to screws that need to be unscrewed and the glass unit removed, the main thing is to remember what was unscrewed and from where, but there are not so many parts, so it is not difficult. We unscrew the fittings and wash them with soapy water, dry them well, lubricate them with silicone grease and put them in place. If some parts are worn out and need to be replaced, take them with you to the store, this will make it easier to explain to the seller what you need if you do not understand technical terms.

The main thing is that all mechanisms need regular lubrication; this procedure must be carried out after each window washing

Consequences of depressurization of a double-glazed window and ways to eliminate them

Depressurization of a double-glazed window will entail a deterioration in all technical characteristics of the window:

thermal insulation;
sound insulation;
fogging in cold weather.

Which windows to choose - plastic or wooden. Review of characteristics, costs, advantages and disadvantages.

Read about the types and rules for choosing combination windows here.

If water appears inside the glass unit or it fogs up from the inside, then the only effective solution is to replace the glass unit. This is a simple operation that does not require dismantling the window frame. You just need to pull out the old glass unit and install a new one.

How to reduce window fogging in the cold season, read the article How to reduce moisture condensation on plastic windows.

It is very difficult to repair a depressurized double-glazed window at home. After all, even if it is possible to find and eliminate a leak in the structure, the window will still fog up, because the air inside the double-glazed window is humid, and moisture does not evaporate from the sealed space.

Aesthetics

First of all, it is worth carrying out a visual inspection; already at this stage various errors may become apparent. When inspecting double-glazed windows, you should pay attention to traces of building solutions (both on glass and plastic); some types of modern construction chemicals are incredibly difficult to clean. Inspect the glass for cracks, chips, scratches, if any, it is better to insist on replacing the glass unit, otherwise after a while you will have to do this at your own expense. Inspect the plastic elements - window sill, surfaces of plastic frames, ebb.

This is a list of “tools” that help the owner determine whether new custom-made wooden windows will protect the room well from the penetration of dust, noise, dirt, and cold air from outside. So:

Method one: painting the seal. To check the tightness of the joints, take colored chalk or washable paint and apply it to the seal. Close the window sash tightly, then open it and carefully examine the trace. If the line of paint or colored chalk somewhere turns from solid to intermittent, it means that in this area the seal does not fit tightly to the frame. Note: when choosing a seal, give preference to elastic synthetic products. They do not harden in severe frosts and do not become excessively soft in hot weather;
method two: checking the tightness with a sheet of paper. Insert a piece of paper between the frame and the sash. Close the window and try to carefully remove it. The sheet does not move - the closure is tight. Repeat the procedure around the perimeter of the window sash: bottom, top, sides. The disadvantage of the method is the impossibility of establishing a tightness at the place where the hinges are attached;
method three: detecting air leaks using a candle. Light a candle and bring it to the junction of the closed sash and frame. If the flame deviates, the seal lets air in from the outside, burns evenly, and the joint is sealed. It is more useful to use the method in windy weather, then the slightest defect becomes noticeable;
method four: wet hands. A simple and effective leak test that does not require any equipment. The only thing is that you have to “trust” your sensitivity. Wet your palms and move them along the perimeter of the glass unit. The moisture allows you to feel the slightest breath. The method is not suitable for testing in windless, hot weather.

How to check windows after installation - 9 important nuances

In order for the windows to last at least 40 years as advertised, and at the same time demonstrate the wonders of heat and sound insulation, it is important that the installation is done with high quality.

You can check the windows after installation yourself, even if the only thing you are good at is ballet.

How to check the quality of window installation. Rule No. 1 - the most important

Do not check the quality of installation during installation itself. Don't get on the installer's nerves. Few people will like to work if someone is standing behind them with Kashpirovsky’s gaze. From such psychological pressure, even the most professional installer will want not to install a window, but to go out through it. Well, or at least he will be in a hurry, nervous and make mistakes.

Checking the window profile

A high-quality profile will provide reliable thermal insulation of the room at any time of the year. Each profile has several internal chambers, hollow or filled with insulation.

According to building codes, a profile with at least 3 chambers can be used for residential premises. Two-chamber profiles are used only in non-residential premises.

It is believed that German profiles are of the highest quality.

Indeed, Germany has created one of the best technological cycles for manufacturing window profiles in the world.

At the output, a multi-level check is performed, eliminating the possibility of defects.

The most popular brands are Rehau, KBE, Veka, Gealan. These companies provide a guarantee on their profiles for about 40 years.

If the profile is even thicker, then a thicker glass unit can be inserted into it.

Inside the profile there is a reinforcing metal contour, which has a square cross-section.

The best quality has a galvanized steel contour, and the metal thickness should not be less than 1.5 mm.

Some unscrupulous manufacturers may not reinforce their profiles with metal at all, since it is very difficult to check its presence visually.

However, this can be done using a magnet, attaching it to the profile in those places where there is no sash. If there is a metal contour inside the profile, then you will feel it.

Pay attention to the window sill

If a window sill was installed, make sure there are end caps on it.
Check the installation of the window sill. It can be installed in 2 options:
Close to the frame. The method is used if it is impossible to install a window sill under the frame. In this case, the resulting seam is sealed with silicone sealant.
The window sill must be recessed into the wall on both sides.
The window sill should not sag when you press on it. Typically, such a deflection occurs if insufficient mounting foam is poured under it, and voids form.