Why do wooden windows “sweat” and what to do about it?

Every year, with the arrival of cold weather, owners of apartments and houses with wooden windows face the same problem - fogging. All attempts to insulate window openings with silicone, polyurethane foam and other materials sometimes only further aggravate the problem. In especially severe cases, windows create real “sobs” when condensation flows onto the window sill, and from it onto the floor. As a result, the shutters swell and opening them in the spring turns out to be quite difficult.

But the problems are not limited to this: houses become damp and cold, and sometimes mold or even mildew may appear. After several years of dealing with such a problem, you may even come to the need for expensive window replacement. First you need to understand why wooden windows sweat, and only then decide what to do in such a situation.

Deterioration in the quality of “sweating” wooden windows

Condensation, constantly present on the surface of wooden products, noticeably worsens their condition and shortens their service life. When applied to window frames, this rule is doubly true - after all, moisture not only constantly flows onto the wood, it flows to where it cannot evaporate naturally - into the thinnest gap between the glass sheet and the wooden plank! If we also take into account that only the outer parts of wooden frames are usually covered with varnish, paint and other types of protective films, it becomes clear that condensation causes irreparable damage to the structure.

Before deciding what to do if wooden windows fog up, you first need to understand the reasons for this phenomenon.

Why do wooden windows sweat?

Glass, both in wooden and PVC frames, can fog up in different ways. If moisture forms on the inner glass on the side facing the room, this most likely means an increased level of humidity in the room. This phenomenon is especially common in the kitchen when preparing food, in crowded small rooms or poorly ventilated bedrooms. In the kitchen, condensation is formed due to the active release of moisture into the air when water boils, and the lower the air temperature and the hotter the water in the pots, kettles and sink, the greater the amount of water vapor will be in the room and the more the glass will “flow”.

If the side of the window glass that faces the inside of the frame (the outer side of the inner glass and the inner side of the outer glass) fogs up, we can talk about a seal failure. If a double-glazed window on a wooden base is used to furnish a window and a similar effect is observed, there can be only one conclusion - there was a defect in the production. In a conventional frame made of boards and slats (jointwork), this defect means poor sealing of the glass.

The option of glass fogging along the edge (in places adjacent to the frame) means that the spacer frame (a strip of material separating the outer and inner glass) has too high thermal conductivity, which leads to the formation of a so-called “cold bridge” and a decrease in the temperature of the glass sheet in the room. A lower temperature compared to the rest of the surface causes condensation to accumulate in this area.

Conquering excess humidity with windows

In order to improve the operation of natural ventilation in an apartment with plastic windows, it is necessary to carry out the following operations:

• Install supply valves on the windows . It is better to choose systems whose sensors automatically regulate the flow of fresh air into the house depending on the level of humidity inside the room. Thanks to them, there will be no need to ventilate rooms by opening windows. Most climate control valves are installed in the upper part of the window - on the sash and frame. The advantage of this solution is the ability to integrate window ventilation into existing plastic windows.
• Install heated windows . Such a system does not require a radiator in the room, since this mission is undertaken by a special double-glazed window. Heating windows work great in small spaces, especially in the kitchen, allowing housewives to rationally use the usable space. A heated double-glazed window helps level out the temperature difference between the outside and inside air, therefore preventing fogging of plastic windows. It is noteworthy that such a double-glazed window can be installed on existing windows.
• Install PVC windows with internal profile ventilation . If you are still thinking about buying new windows, then you should consider this option. The so-called “breathing” windows will provide a favorable microclimate in the house, independently solving the winter and autumn problems of plastic windows. This is provided for by the very design of the profile system, into which the labyrinth-air duct is integrated. Well-thought-out air flow circulation ensures that the likelihood of plastic windows fogging is reduced to zero.

Ways to deal with condensation

The fight against condensation is carried out in different ways depending on the reasons that cause it. When the inner surface of a window fogs up, caused simply by increased humidity in the room, the main ally becomes high-quality supply and exhaust ventilation or at least regular ventilation - at the same time, the humidity level decreases and the windows delight the owners with a clean, dry surface.

What to do if wooden windows inside the frame fog up? There are two possible options here. The first is the simplest and most radical - replacing the window. But this is not always possible and necessary. The second option is more complex and requires special skills. It is required to vacuum (make airless) the space between the individual parts of the frame as efficiently as possible or, conversely, to establish high-quality ventilation of the same space. This is a rather complex and not always effective process. Traditional methods of dealing with “sweating” windows (rubbing the glass with a special composition from a mixture of glycerin, alcohol, liquid soap and other similar components, pouring salt or cotton wool into the space between frames, and similar methods) rarely bring the desired result.

Fogging of glass along the contour can only be combated by replacing the window as a whole (if a double-glazed window is used) or, again, carefully sealing the frames.

The general conclusion from the above is quite simple: in order not to incur extra costs for ventilation, additional sealing and other operations in the future, it is better to immediately purchase high-quality wooden windows with reliable sealing of the glass unit and a heat-insulating spacer frame.

We produce Euro-windows from laminated Angarsk pine timber from larch or oak wood, in three price categories, which will allow you to choose an option based on your budget.

New products on the market are usually well-forgotten old ones. The same thing happens with windows. Wooden windows are at the peak of popularity.

They displace plastic competitors due to their naturalness and durability. Modern wooden windows look very attractive and stylish.

Unlike other types of windows, wooden ones can be restored and improved with pleasure!

Wood is a very durable natural material. It is completely non-toxic, which makes you choose it.

But there are other advantages:

• Durability and reliability
• High level sound insulation
• Good thermal conductivity
• Possibility of restoration
• Attractive appearance suitable for any interior

But some 6-7 years ago the windows were not impregnated with anything and now it is impossible to avoid problems. It happens that a wooden window does not close.

This can happen from swelling of the paint due to humidity or swelling of the frame itself. Layers of old paint will have to be removed. You can do this with a hammer and chisel, a hair dryer, or you can use equipment!

Arm yourself with an electric planer and remove the layer of wood that interferes with closing. If one swollen layer of paint is in the way, you can carefully clean it with sandpaper! Repaint the clean surface.

Old wooden windows are practically not subject to “crying”, since they are not completely airtight, they are provided with excellent ventilation.

But modern wooden structures with insulation and double-glazed windows are completely sealed and do not allow air to pass through.

Therefore, condensation is created, the window becomes wet, streaks form, and sometimes a real swamp forms under the window sill. The air contains a huge amount of water vapor.

• In the kitchen - from using a gas stove, cooking
• In the bathroom - from excessive use of hot water
• In the bedroom - moisture evaporates from our bodies (up to 1 liter per day), from indoor plants
• An aquarium of impressive size is also the culprit of moisture on the windows
• If the batteries are installed incorrectly

You can solve the problem in different ways:

• Ventilate rooms more often
• Get a powerful hood
• Replace the double-glazed window with a double-chamber one
• Remove potted flowers from the windowsill
• Do not veil the battery with curtains
• Buy a dehumidifier
• Install the supply valve

One of the methods will definitely help you get rid of a wet window!

The inevitable problem with wooden windows is life in a fog. They sweat for many reasons and, unfortunately, antiperspirant will not help them. First you need to identify the cause, and there are many ways to eliminate this problem.

We overcome excess humidity with the help of heating systems

To improve the effect of natural ventilation in a room with plastic windows, it is worth installing a radiator under the window. Users do not always understand why heating systems are predominantly installed under the window. This is due to ensuring normal air circulation. Heaters should be installed on the coldest walls, and therefore on the outside. The average window has almost three times the coefficient of heat transfer resistance compared to a wall, which is why under it is the best place to place a heating device. Mounting a radiator on an interior wall will cause excessive cooling near the exterior walls (near the window).

The best proven way to ensure effective ventilation in modern homes with plastic windows is to use a supply and exhaust ventilation system with an air preheating function (preferably with heat recovery).

Supply and exhaust ventilation with heat recovery provides:

• Removing excess moisture from the room,
• Air filtration,
• Effective odor removal,
• No drafts,
• Minimal penetration of street noise,
• Constant flow of fresh air.

However, for the supply and exhaust mechanical ventilation system to work optimally, PVC windows and external doors must be airtight, without any additional active gravity ventilation channels, such as supply valves.

If you have an old radiator installed in your house and you decide to disguise it, then you should not forget about proper air circulation. When choosing a screen for a radiator under a window, you should not sacrifice comfort for the sake of beauty.

A little investigation

But first, a little science.

Dew point

Water vapor is always present in the air. Its transformation into water occurs through the interaction of two factors - high humidity and low temperature.

There are two dependencies here:

• the higher the air humidity, the higher the dew point - steam condensation, and,
• The lower the room temperature, the lower the dew point.

In numerical values, the above statements result in the following dew point indicators:

• relative humidity (%) – 40:

• room temperature (degrees) – 22: dew point – 7.8;
• 21: 6,9;
• 20: 6,0;
• 19: 5,1;

• relative humidity (%) – 50:

• room temperature (degrees) – 22: dew point – 11.1;
• 21: 10,2;
• 20: 9,3;
• 19: 8,3;

• relative humidity (%) – 60:

• room temperature (degrees) – 22: dew point – 13.9;
• 21: 12,9;
• 20: 12,0;
• 19: 11,1;

Hence the first conclusion is to look for sources of high humidity.

Sources of high humidity

Several of these sources include:

• Firstly, the cold air itself. The reasons for its appearance may be:

• Insufficient heating of the air in the room, and the lack of temperature in the room is permanent. Here, pay attention to the operation of the heating system, including the location of the radiators strictly under the window sills. If the room is regularly maintained at normal room temperature, fogging, as a rule, does not occur.
• Constant flow of cold air into the room
  . The reason for this situation may be a problem in the design of the windows; they simply let cold air in from the outside. The solution to this problem can, of course, be a thorough examination and sealing of all possible cracks, especially between the frames, sealing the frames with tape during the cold season and simultaneously placing all kinds of insulation between the frames. This will not solve the problem radically, but it will give a positive result. But by and large, here you need to think about replacing the entire structure with a newer one. (See also article.)

• Secondly, the lack of proper air ventilation throughout the entire volume of the room. As a result, the accumulation of air along with water vapor in certain places in the room, an increase in the level of humidity, and with a slight drop in temperature - dew on the walls and windows:

• The solution to this situation, again, may lie in the area of ​​increasing the temperature inside, increasing the dew point for the same local humidity.
• Another solution, already cardinal, is to install air conditioners in the room.
• And, the third way could be to install window structures with built-in ventilation valves. Such innovative designs can be found more and more often on the market.

• Third, the existing source of moisture in the air:

• These can be wet floors, which is very important for the basement and first floors of country houses with poor foundation drainage.
• This can be constant heating of the room with gas, and gas, as is known, contains significant impurities of water vapor.
• It may be that there is too much indoor vegetation that needs to be watered regularly. As a result, there is a very high level of water vapor.

Several ways to protect interior glass from moisture

These methods are temporary and are only suitable as additional protection:

• Lighted candles placed on the windowsill will warm the air near the window and prevent condensation from settling.

• Combine glycerin with alcohol in a ratio of 1 to 20. Wipe the glass with a cloth soaked in the mixture. After the alcohol has evaporated, polish with a dry cloth.
• Wipe the glass with half a lemon and wipe dry.
• Dissolve tooth powder or chalk in water until the solution is slightly whitish. Wash the glass, dry it and wipe with crumpled newspaper until it shines. This is how glass was washed in the last century, when there were no special products.

The design of the windows themselves

We also pay attention to the design of the windows.

The choice of glass in three rows is not at all uncommon

The mechanism of moisture formation here is as follows:

• As two initial premises we have:

• the room temperature is quite comfortable - 23 degrees;
• There is moisture in the air, you can’t go anywhere without it, but there is no need to talk about its excess content - so the question arises of how to eliminate fogging of wooden windows, in this case, what to do when there seems to be no visible reason.

• in addition, it has been checked that the windows are not damaged and do not allow cold air to pass through;
• and the reason is that the temperature outside is significantly lower than the temperature inside, and moisture begins to condense in the air layer near the window;
• The natural way out of the situation is to increase the temperature of the air “overboard” adjacent to the glass from the outside:

• It is clear that this cannot be done if you have antique single-pane windows;
• if the window is made of two glasses, then seal the space between the glasses, increasing the temperature inside. Such a seal on modern windows leads either to their complete inspection and the elimination of ways for cold air to get inside, or to an increase in the number of cameras - installing two or even three cameras. It turns out to be a kind of system of temperature locks, when the air temperature in each subsequent chamber is higher than the previous one.

Helpful advice! Another reason for fogging may be poorly dried wood used in the manufacture of frames. Such wood, in turn, in the future is even more inclined to absorb moisture, which gradually “splashes out” into the room. What is especially unpleasant in this situation is that such a frame will constantly be a source of moisture, a kind of perpetual motion machine of high humidity - it either absorbs moisture or releases it. The best way to get rid of this “factory” is to replace windows.

Prevention of wet windows

To prevent windows from fogging up, it is necessary to take a number of preventive measures.

• Eliminate the wide window sill, replacing it with a narrow analogue.
• Install a through ventilation valve under the window sill.

• Remove greenery and flowers from the window opening or from the room.
• Increase the room temperature or increase the number of heating radiator sections.
• To prevent freezing of the room, insulate the walls of the house outside.
• Move massive furniture away from the windows and remove the blinds so as not to cut off warm air flows from reaching the glass.
• When living in a private house or on the first floor of a high-rise building, systematically check and clean the basement, since this place is the main source of dampness.
• Do micro-ventilation regularly when the room humidity is high.

Important! It is better to provide ventilation all year round, since air circulation at low temperatures outside will improve health and normalize the microclimate in the house.

Improving air circulation in the room, removing excess moisture with anti-grease preparations, and properly washing surfaces will help solve the problem of foggy windows. With proper processing, the glass will remain clean and transparent for a long time, and moderate humidity and comfort will be established in the house.

Causes of window fogging

People who remember their school physics course well know that the reason for the fogging of wooden windows lies in the increased humidity that forms indoors during cold times. Due to the temperature difference between the room and the environment, all moisture settles on the glass in the form of condensation.

Constant accumulation of condensation on the window leads to the formation of mold

It remains to figure out the reasons for the increase in humidity. They can be external or internal. First you need to deal with the first ones. Very often, the reason for high humidity in an apartment is heating with gas . During operation of such heating, moisture is inevitably released, increasing the overall humidity in the room and, as a result, settling on walls and windows.

Cold air penetrates into a poorly insulated apartment, which increases the humidity in the room

If the apartment is not properly insulated, cold air will certainly penetrate into it in winter. As it circulates around the room, it will create humidity. By the way, it is this that becomes the main reason why wooden frames can swell so much over the winter that it turns out to be almost impossible to open them in the spring.

The other extreme would be complete isolation. Many owners, in an attempt to insulate the house, use foam and sealant, but both options have a much greater negative impact than positive ones. The use of these materials for insulation results in a violation of air exchange. Even if the cold does not penetrate, such an approach will not save you from fogging up windows and swelling of frames.

Causes of dew formation

The fact is that the very question of why wooden windows sweat is posed incorrectly. Because both wooden and plastic frames never sweat, at least no one has seen this yet. The frame material has nothing to do with it at all. Under certain conditions, any, for example, expensive Finnish wooden window will fog up in the same way.

The formation of condensation on glass is influenced jointly or separately by three factors: cold air outside, high humidity and a double-glazed window with poor thermal insulation.

In winter and autumn, along with shoes and clothes, we bring a lot of water and snow into the house, which saturate the air and the windows begin to “cry”. At the same time, the wooden structure of the window absorbs the flowing condensate, swells and practically stops opening normally.

An increase in the humidity of the internal atmosphere due to washing and drying clothes and working in the kitchen leads to the immediate appearance of dew on the coldest surfaces in the room, which are usually window glass.

The presence of numerous indoor plants on the windowsills and thick curtains on the windows are other reasons for foggy windows.

Why don’t old wooden windows often “cry”? Due to its structure and condition:

• Old wooden frames have many actively ventilated cracks. If you carefully caulk such a window in the fight against them, it will fog up in the same way, since the temperature difference will increase and air circulation will worsen.
• In addition, the old windows have two frames separated by an impressive space that acts as a buffer. If you bring the frames closer together or leave one at all, the thermal insulation will decrease. It turns out that only double wooden windows do not get wet.

Eliminating fogging

There are several basic methods to help avoid fogging. Most of them don't even require any special skills or equipment.

Ventilate the room more often

Air humidity can increase due to various reasons: cleaning, cooking, drying clothes, and even due to human breathing. If the ventilation in the room is adequate, then problems with condensation can be avoided by periodically ventilating the room. However, if this has to be done more and more often, then it’s time to check the ventilation ducts and, if necessary, clean them or equip them with fans.

Install the correct double glazed windows

When choosing a double-glazed window, you should pay attention to what climate zone it is designed for. Remember: the wrong choice will result in significantly reduced efficiency . When selecting, take into account the temperature and humidity in the room and the climate. For example, for central Russia, double-glazed windows will be sufficient for frosts of -20 degrees, since more severe cold weather is rare here.

When choosing a double-glazed window, it is necessary to take into account the climate

Improve air circulation

In an attempt to avoid drafts, owners of wooden windows try to caulk and seal all sorts of cracks. Unfortunately, because of this, the air exchange between the house and the street worsens: a barrier stands in the way of drier street air, circulation drops, and all the moisture accumulates in the apartment. As a result, we get not only foggy windows, but also swollen frames, which will be very difficult to open.

The polyurethane foam should be removed from such a “sealed” window, starting from the top. It is important to carefully notice changes, if any. If condensation remains, you should continue to remove the seal.

Organize proper heating

There are several key points here. First of all, heating devices should be placed directly under the windows. One of the causes of dew is incorrect installation of radiators or their poor performance . Radiators should be moved under the window - this will simultaneously improve air circulation and help heat the room. Otherwise, there will be stagnation of cold air, and the windows will constantly “cry”. Moreover, in most cases, wooden frames cannot be completely dried unless there is a heat source underneath.

Incorrect location of heating devices

Radiators should be located under the windows; nothing should interfere with the movement of warm air.

Popular decorative radiator grilles, wide window sills, and thick curtains disrupt the circulation of hot air.

As you know, heated air from the batteries rises, near the glass it combines with cold air and falls down.

Thanks to this movement, the glass does not cry during the heating season.

Causes of window fogging

When condensation appears, the cause of fogging of wooden windows is increased humidity, which can appear in the room during cold times. The difference in temperature indoors and outdoors can be large - moisture forms and settles on the surface of the glass in the form of condensation drops.

Calculate the exact cost of wooden windows in.

(Only for residents of Moscow and the Moscow region), send a request to calculate the cost:

Using concepts such as dew point and water vapor, specialists can try to find and eliminate the cause of glass sweating. Sometimes it can be easily eliminated with your own hands.

The reasons why humidity rises can be internal or external. If the heating in the house is carried out using gas, moisture will certainly be released during operation of the equipment. The amount of moisture in the room begins to increase, and the settling of its particles on window and wall surfaces also contributes to the appearance of condensation.

In the absence of complete thermal insulation, cold air gradually enters the home in winter and the rooms become damp.

Because of this, wooden frames swell so much that in the spring the window from the inside, due to a change in size, can no longer be opened.

Another extreme is carrying out insulation with excessive diligence. For example, sometimes homeowners try to use both sealant and foam for installation when performing thermal insulation, resulting in a disruption of air exchange. After such a procedure, the cold will not penetrate inside the room, but it will not protect the windows from sweating and swelling of wooden elements.

Condensation or put up with dampness and lack of comfort in the house

Often wooden windows sweat due to the fault of the owners themselves. The greater the difference in air temperature in the apartment and outside, the longer in such weather a window or window is open for ventilation, the more likely it is that after closing the window, “tears” will flow down the glass, and they can be quite abundant. In addition, if the ventilation in the apartment is not well adjusted, problems with fogging of wooden windows cannot be avoided. Thus, if we are talking about an apartment in a multi-storey building, cleaning and adjusting the ventilation will help to avoid fogging of the wooden windows in it.

It would not be superfluous to take basic measures, which, however, will help identify the sources of temperature decrease and condensation formation on the windows. They can be unclosed or poorly closed doors to the street, entrance, bathroom, toilet.

Increased air humidity in the room also contributes to the appearance of condensation on wooden windows, which is formed as a result of washing, drying wet things on radiators, etc.

In addition, thick curtains on the windows, as well as a large number of indoor plants on the windowsill, which also breathe, will cause wooden windows to sweat.

Oddly enough, but old wooden windows, in which cracks form over time, or new, but not very high-quality windows, which also do not avoid the presence of cracks and cracks, fog up much less, because it is through the micro-cracks that fresh air leaks in, which to some extent regulates the internal temperature in the room and promotes the circulation of fresh air. This is why wooden windows with slits sweat much less, no matter how funny it sounds.

However, if the room temperature is below +17 degrees, glass fogging is also possible.

Eliminating fogging

To prevent high air humidity from spoiling the atmosphere of the room, it is worth familiarizing yourself with methods that will help prevent it. Many options do not require special equipment or special skills.

To ensure that the air humidity in the apartment does not exceed permissible limits, the ventilation in the room must be well equipped. Humidity changes due to wet cleaning, drying washed clothes, and preparing dishes in the kitchen.

With good ventilation, you can try to prevent the formation of condensation by performing regular ventilation.

The presence of problems that cannot be dealt with most often means the appearance of blockages in the ventilation ducts. They will need to be cleaned or supplemented with fans.

Install the correct double glazed windows

When choosing double-glazed windows for installation, you need to pay attention to what climate the product you like is designed for. When choosing, you must take into account the humidity and temperature in the room, as well as some climate features. If, when buying double-glazed windows, you choose the materials incorrectly, their efficiency during operation will be low.

Improve air circulation

Many homes undergo thorough caulking and seal any cracks. But in this way it is often possible to only worsen the air exchange between the street and the interior of the house. By disrupting the air circulation in the room, the owners get an accumulation of moisture in the apartment, subsequently condensing on the windows, it saturates the frames, which because of this greatly increase in size.

To correct the situation, you will need to free the window from the polyurethane foam. You need to start the procedure from the top. It is important to pay attention to how and when the design of the wooden frames themselves changes. If condensation continues to bother you, you will need to remove the rubber seals and replace them with new ones.

Organize proper heating

To maintain positive temperatures in your apartment, it is necessary to build the heating structure in such a way that the radiators would certainly be under the windows. Installation of air conditioners and radiators, if done incorrectly, can be one of the reasons for the appearance of dew.

When heating appliances are located away from windows, heating the room is poor. Simply moving the heating devices changes the air circulation, which creates an unhealthy atmosphere. With the correct location of heat sources, it is possible to prevent stagnation of cold air, due to which the windows ooze moisture. Without a nearby heating device, it is difficult to dry wooden frames even in the warm season.

How to eliminate condensation on apartment windows

The following measures can be taken:

1. Ventilate the room regularly. This is especially necessary when the window design does not provide automatic air exchange.
2. Light candles on the windowsills. The heat from the candle creates an air convection effect and humidity is significantly reduced.
3. Use a fan, directing the air flow towards the window.
4. Use convection screens - plates designed to direct the flow of warm air from the heating system to the window structure.
5. Use the winter ventilation option, which is available in all modern window designs.

All these methods allow you to solve the problem of window ventilation. And if the room temperature is low, you need to warm up the room. In a house where there is a stove, heat it, and in the apartment use additional heating sources.

“Correct” double-glazed windows

Often, instead of wooden frames, double-glazed windows are installed; the choice of materials is made taking into account factors such as:

• climate;
• location of windows;
• noise level;
• number of storeys of the building;
• the presence of a loggia.

In case of cold winters, it is necessary to purchase a plastic structure, taking into account its heat-insulating properties. The thickness of the glass unit has an effect if the gap between the glasses is 16 mm. The owners purchase a single- or double-glazed window. When installing a plastic window, you will need to remove the rubber seals. Glass saves energy well and retains heat if it is 24 mm thick.

It is recommended to buy double-glazed windows with energy-saving details, because in this case, fogging of the windows is prevented, heating costs are reduced, and fittings and furniture located in the southern part of the house are preserved.