How to seal windows for the winter?

How to seal windows for the winter?

Wooden windows are environmentally friendly structures, create a comfortable indoor climate. Due to these features, many do not want to part with them. But over time, the tightness of the frame decreases, and the window becomes a conductor of cold and draft.

There are different ways to solve this problem. To, how to seal a window for the winter and insulate the gaps between the frame, box and door frames, depends on it, how long the repair should be and how much time and money you want to spend on it. Both the old thermal insulation methods are effective to a different degree, which our grandmothers used, as well as modern ones, made with new materials.

Searching for the cause of cold windows

So that the work on insulation would not be in vain, it is necessary to correctly determine the weak point of the window, that lets cold air through. The cause may lie in different parts of the structure:

  • Jamb (the insulation has deteriorated or is missing);
  • Parapet (Cold gaps or bridges can form in the lower part, which are invisible at first glance);
  • Glass (blowing occurs in the places where the glasses adhere to the frame, The putty closing the joint deteriorates over several seasons and requires regular replacement);
  • Frame and wings (shrinkage of the tree, sagging wings, ground movement under the house – all these circumstances lead to the formation of gaps between the frame and the window frame).
Damage to the wooden window frame leads to heat loss in winter

If visual inspection does not identify the cause, some tricks can be applied. For example, wet your hand with water and apply it to different parts of the window. An even more sensitive method is with a lit candle or lighter. The flame reacts to any air movement, and they will show where heat is lost.

A very old window requires an integrated approach. For good thermal insulation, all possible thermal bridges should be eliminated . Structures in good condition can be insulated around the perimeter of the frame and opening windows in any way.

How to repair cracks

The most common problem, faced by homeowners with wooden windows, is the appearance of gaps between parts of the structure. They arise as a result of changes in the geometry of the window and the window opening. In some cases, it is sufficient to adjust the closing position, by tightening the fastening hinges. But most often cracks need to be repaired. You can use many handy and specialized materials for this purpose.


Good insulation is obtained from cellulose fibers. You can make it yourself from toilet paper or newspapers . To do this, you need to grind the paper and pour water over it. When the mass becomes soft, it should be squeezed out of the water well. To make the putty more durable, add the same amount of clay and twice as much crushed chalk to the cellulose.

Tapping a window with paper is one of the easiest ways to insulate your home for winter.

The mixture should be used immediately for its intended purpose. You can insert it into the slots with any convenient tool, for example with a knife or spatula. It is recommended to stick the sealed gaps with masking tape, with soap paper or cloth.

This way you can insulate the windows for the whole winter. But it will not be easy to remove the composition from the cracks and the frame, in addition, traces will remain on the surface, which can only be removed by painting.


This method of insulating wooden windows with cotton wool for the winter is probably the oldest, fastest and cheapest. It is necessary to tear off pieces of cotton wool and arrange them tightly in the gaps in the window structure. It is recommended to use a screwdriver or a knife to seal small gaps.

Cotton wool is the cheapest, but also the most short-lived isolation

At the end of the work, it is also recommended to seal the gaps with paper or fabric tape. The sealed seam is more tight and aesthetic.

The advantage of this method is this, that in the spring it is easy to remove cotton wool, and the window will not lose its appearance. Warming will be effective in one season, because cotton fries and thickens from time to time and under the influence of moisture, so the gaps will have to be refilled every year.


Insulation of old wooden windows can be done with ordinary pieces of sponge or with a special adhesive-based foam rubber tape . Due to the large number of air chambers in the pores, this material provides good thermal insulation, but does not protect against traffic noise.

Thermal insulation of windows with a sponge

Pieces of sponge can be pressed into the gaps between the frame and the box or placed around the perimeter of the working leaf and tightly closed. If necessary, the insulation can be removed very easily.

Rubber seal

Adhesive tape made of rubber or polyurethane can last more than a year. And it can insulate the window very quickly. The only drawback is this, that you will have to spend money to buy the tape.

Insulation in the form of a tube with a cavity inside – This ensures that its shape is retained even with the active use of the sash. Gluing the joints is not required – to również plus .

Thermal insulation of windows in Swedish technology is a quick and reliable method of insulation, but also inexpensive

Similar materials are used for thermal insulation of wooden windows in Swedish technology. But before installing the tape, recesses are made around the perimeter of the frame and the wings, into which the insulation is then inserted.

How to reduce heat loss through glass

Even double-glazed windows made of metal-plastic windows are always cold. The main heat loss occurs through this part of the structure. In the case of wooden windows, the situation is particularly difficult – the glass is simply inserted into the groove and does not fit tightly.


This method of window insulation partially solves the problem of adhesion of the glass to the frame. But enough for 1-2 season. Then the procedure must be repeated.

The putty ensures that the glass fits perfectly to the frame

For waterproofing, a special putty for windows or plasticine is suitable. These materials are equally flexible and adhere well to wood and glass. They are placed on the outside of the window at the junction of the glass with the frame. Before using a small piece of material, it should be kneaded and covered with an even layer, pressing it down lightly. The key disadvantage of this method is the destruction of the putty, when it freezes, and plasticine melts in the sun.

Silicone putty

The method of sealing the joint with silicone or acrylic sealant is more reliable and more durable than the first. But at the same time more troublesome and more expensive.

It is recommended to purchase a neutral-colored silicone for work. The sealant is applied to the glass socket, that is, in the groove. Therefore, the glass will have to be removed. The composition should be squeezed out with a uniform strip around the perimeter and immediately put the glass in place and again pass the sealant along the seam.

Sealing the connection between the glass and the frame with mastic

Important trait, One thing to keep in mind when choosing this warming method is this, that the sealant hardens, so it will not be easy to pull the glass out of the frame if necessary.


According to the manufacturers, heat-reflecting foil can reduce heat loss through glass by 30% . It is glued directly to the glass.

Heat reflecting foil can be glued to the glass

To protect the windows in this way for the winter, the surface should be cleaned of dirt and degreased, and then cut a sheet of foil with a margin 2 cm on each side. Tear off the bottom layer and put it on the glass. Glue it over the entire surface with smoothing movements. If folds have formed, they can be heated a little with a hair dryer, and cut off the excess with a clerical knife.

Window sill insulation, drainage and slants

If there are no gaps on the frame, and the heat is still escaping from the room, the problem may be the presence of cold bridges in the space under the sill or inside the slants. In this case, repair and insulation of wooden windows will be required at the same time.

Polyurethane foam

Universal window insulation – polyurethane foam. It is used to fill gaps.

To exclude heat loss from under the window sill, it is necessary to clean the space under it from the old fallen plaster, scattered foam, lumpy cotton wool or other types of insulation, which has become useless. Then mount the foam in the gun and blow it into the slot. Please note, that the foam increases several times. The excess foam can be easily cut off with a knife after drying.

To seal large gaps under the windowsill, it is better to use polyurethane foam

In addition, foam is blown into the gap between the frame and the wall and along the edges, and then any insulation is laid, and the slants are made of plasterboard, plastic or sandwich panels. Temporarily fix it to the wall with masking tape. Seal all joints.

Polyethylene foil

The insulation of windows in a wooden house can be done by other methods. A new and still insufficiently proven method is to seal the window opening with a completely transparent plastic film . The method is not entirely aesthetic, because it is difficult to stick the foil very evenly. It can only be partially smoothed with a hair dryer. But judging by the reviews, the method allows to reduce heat loss through the window to the level of a blank wall, which is much more effective than gluing or sealing cracks.

Sealing the window opening with foil significantly reduces heat loss, although it does not look very aesthetic

The foil is put on in different ways:

  • Double-sided tape;
  • Furniture stapler;
  • Masking tape.

This cold protection is easy to install and remove. The same foil can be used multiple times.

Because old wooden windows can be insulated for winter in different ways, it's best to use several at once, to eliminate not only the obvious problems, but also these, which may appear during frost.

Self-insulation of windows is recommended in summer or autumn, because many works cannot be done in the winter season.

One thought on “How to seal windows for the winter?”

  1. A rubber gasket will work best for me. It was true that the window was difficult to close, but it was tight all winter. Unfortunately, the next season had to be sealed again. Regards.

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