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How to buy a wooden window? Which “economizing tricks”
manufacturers use to make more favourable window offers,
and who benefits from it?

John Ruskin’s wisdom about the quality
Estonian economy is facing complicated times. Window manufacturers, among others, are fighting for survival, forced to find more and  more “economizing tricks. ” How and with what price it is achieved?

The most effective way to sell one's products is to offer a price that is attractive to customers – which is really good in principle. Alas, there are no free lunches,  and the customer-friendly price has its own price. Taking advantage of the ignorance of the customers, many window manufacturers do not add significant components on their products and replace important components with cheaper ones.

Low quality materials are often used for refining the windows and preparing the wood, which is completely unacceptable considering the impact on longevity, thermal insulation and sound tightness of the windows. This does not matter,  since by offering a low price all the adjudications are won and even windows of the worst assembly quality withstand the offered 2-year guarantee. But in a few years customers will again face the question, which windows to choose now?

Besides taking advantage of the customer and damaging their own reputation,  it unfortunately also promotes a notion that wooden windows are low-grade products and do not withstand our Northern climate. Hopefully the information in this article is helpful for future window buyers to make right decisions, and helps to restore the reputation of wooden windows.

Choice of Materials

Estonian window manufacturers usually offer finger-jointed pine wood windows. Pine wood is divided into quality heart wood and more tenuous sub-bark sapwood. Of course it is more useful for the window manufacturers to save on expenses, and produce from the latter and say to their customers that it's all the same pine. Also some manufacturers use even lower quality wood with knots. In that case the price should not be on a par with sorted knotless wood products.

Laminated and finger-jointed spruce timber
Laminated and finger-jointed spruce timber
Due to the lower density of sapwood also the hinges, latches and locking details fixate more weakly. This makes the window less thermally resistant and soundproof, and shortens its lifetime.

All conifers contain bigger or smaller amounts of resin. Because the resin nests are often situated below the surface layer, they can be left unnoticed while handling the wood.

When darker paint tones are used, and on the southern and western side of the building, on warm summer days (when the temperature of the wood can rise up to 65-85 °C) such resin nests may often start “boiling” and press themselves under the paint as a bubble or even through the finishing coat, spoiling the appearance of the window. It is just a cosmetic defect which in case of conifer wood cannot be avoided to the end.

If low quality conifer wood is used with light paint tones, during approximately one year the knots turn yellow and gleam through the finishing coat on the dayside of the building. If such a situation is disturbing, it can be fixed by removing the paint from the resin knots and correcting the layer of paint. The problem generally does not reoccur later.

Laminated Okoume timber
Advice: If a resin nest is pressing through the paint, it should not be furbished instantly. Instead it should be left to dry for approximately one year, and then the dried resin bubble can be cautiously removed.

Less price sensitive customers prefer selected pine, meranti, oak or okoume wood imported by our company (no finger joints on the outer as well as inner window surfaces) as the material for wooden windows.

Usage of such materials guarantees a beautiful and exclusive result and this especially when lighter stain tones are used.

Window manufacturer saves with each 2 m² window: approx. 150 EEK

Preparation of Timber

Okoume window inner side, finished with transparent stain
To achieve a deceptive competitive advantage before heart wood, deep soaking is used for sapwood. Deep soaking is not necessary for heart wood because of the high resin content (soaking can penetrate the heart wood just up to 2-3 mm deep). Even after elaborate deep soaking sapwood will cost less than heart wood.

Neither is deep soaking a miracle cure that would compensate for the compromise made with the choice of material. But as a sales argument deep soaking works well with less informed customers.

For wooden windows, it is of special importance to process the material with high quality impregnating and primer coating materials, which guarantee an ideal adhesiveness for the paints used for the final refining. But many window manufacturers, to save on expenses, have decided to cut back on pre-processing, applying the paint straight onto wood, so that it will probably soon crack and flake off.

Such shamelessness deserves more attention than it has been given. Recently we have been replacing the windows of many houses built less than 10 years ago, and this how we know a lot about economizing tricks of some window manufacturers.

Window manufacturer saves with each 2 m² window: approx. 100 EEK

Coat of Paint

RAL color catalogue
Tone darkness table for finishing of WOODEN WINDOWS
It is known that wood is a “living” material that either contracts or expands, depending on the climate. This is why it is extremely important to use special high quality window paints that have an elastic structure and which are able to play along with the wood. Because these paints are a lot more expensive than ordinary wood paints, many window manufacturers prefer not to use them.

The result is windows with cracking surface and here it is not only a cosmetic defect. Namely it gives humidity an easy access to the wood, especially in the connections of the window profiles, which are most sensitive to the changes. The outcome is ugly wooden windows with deteriorating finishing, which will require a lot of time and work to restore.
Window manufacturer saves with each 2 m²2 window: approx. 100 EEK

Joint Filling Materials

Window manufacturers that offer a low price instead of quality also prefer not to fill the sash and jamb joints with special mastic that plays with the wood, like the elastic paint layer does. Saving on joint mastic increases the risk of joints cracking, which enables the humidity to get under the paint and damage the wood.

Window manufacturer saves with each 2 m² window: approx. 40 EEK

Closeness of window fitting locking items

Required frequency of window locking items installation
For the sash to close tightly against the jamb, in case of “tilt & turn” wooden windows the closing points of the lock and hinges have to be installed after a minimum of 800-1000 mm. Unfortunately, often we come across windows where the distances between closing points are up to 1200 mm. Why do the locks have to be located so densely?

As mentioned, wood is a material that is “alive”, so with a big distance between closing points the windows lose their density while “playing.” As a consequence one has to heat the stove or turn up the heating to preserve a normal room temperature. And this way winter after winter, for the sole reason that the window manufacturer decided to save 100 EEK on the lock and the customer did not know to pay attention to it when ordering the windows.
Window manufacturer saves with each 2 m² window: approx. 100 EEK

Compensation Gasket

Compensation gasket
Compensation gasket is installed between the window packet and the sash and its goal is to prevent the tension on the glass packet when the wood swells and “plays.” Such tension can cause cracking of the glass packet. Additionally it guarantees a better thermal insulation and soundproofing for the window. Since it is an unnoticeable detail, many window manufacturers have decided to save also on the installation of this gasket, hoping that their produced window will last for the guarantee period.

And even if some of 100 installed windows do not last, the glass packet is simply replaced, and waiting for the end of the guarantee period continues. Moreover, the customer first has to prove that the window really cracked due to the fault of the manufacturer, not the owner himself.

And even if the glass packet is replaced, one still has to live in the fear of it breaking again, until the end of the windows’ lifetime.

Window manufacturer saves with each 2 m² window: approx. 50 EEK

Grooves for Installation Foam

Grooves for installation foam
The optimal thickness of “tilt & turn” sashes and jambs is 68-88 mm (NB! With a wider jamb and a thinner sash the resulting thermal insulation depends on the one that is thinner – this is why it is not necessary to ask for wider jambs by any price). To achieve an effective and durable installation, isolation grooves for installation foam have to be milled to the outer edge of the jamb.

Primarily to save time, some window manufacturers see a possibility to save money even here, which can bring about lots of unpleasant experiences for the customers.
Window manufacturer saves with each 2 m² window: approx. 50 EEK


As it can be seen from the calculations, saving on what seem to be trivial things at the first sight, window manufacturers can leave 590 EEK in their pocket with each 2 m2 window. Considering that bigger wooden window manufacturers make approx. 50 000 windows and balcony doors each year, the saved sum is 590 x 50 000 = 29.5 million EEK. As you can see, we are talking about large amounts of money that are hard to give up.

For the customers such economizing tricks of the manufacturers mean considerably bigger heating bills and windows with a shorter lifetime than hoped for.

Advice! In the current economic situation, saving a drowning man is that man's own problem, as a Russian proverb puts it. That is why it is useful to memorize questions to ask from the window manufacturer.

Questions to determine the quality YES NO

Are the wooden windows made of quality timber (material consists of little sapwood and has no knots)?
Is the painting of the windows preceded by an additional impregnation and primer coating of the corners of the details, finished sash, and jamb? Can it be checked?
Are water-based, breathing, special window paints of an elastic structure used and can it be checked?
Are the joints of the sash and jamb filled with an elastic structure, joint mastic that is especially designed for windows, and can it be checked?
Are the closing points of window locks (including hinges) installed after at least 800-1000 mm?
Is a compensation gasket installed for the windows and can it be checked after the installation?
Are grooves for installation foam milled to the outer edge of the jamb?
Does the gasket of the lower frame profile close tightly against the edge of the wooden window jamb, so that the wood board of the jamb breaks the heat bridge completely? Solutions where the gasket of the sash closes against the aluminium water board of the jamb (including breaks that are partly plastic) are not solutions for the best thermal insulation.

Kalesi’s answers to these questions are affirmative.

This is the reason why we are usually not found among the winners of offers that are oriented towards the lowest price. Instead we can look our customers into the eyes without shame even after 20 years. Our standpoint is that we would rather stop producing than put a Kalesi stamp on a low quality product.

Additional questions to investigate other useful properties and possibilities YES NO

Do the windows have a long guarantee period of three or more years?
Is it possible to order the wooden windows with different tones, or finishing material (for example paint and stain or stain and oil) from the inside and outside?
Is it possible to order energy saving passive windows that have an especially good thermal insulation?
Is it possible to order counselling for energy saving window installation?
Is it possible to order the window installation with a multifunctional expansion gasket solution (for example „illmod Trioplex”) that is created primarily for energy-saving installation of windows and doors? Its advantages are good resistance to air, water, diffusion, and UV rays. The gasket guarantees thermal insulation for the whole installation depth, and such installation gasket will not crack if the building sinks or moves, nor as a consequence of strong wind or normal use.
Is it possible to order a service of dismantling and disposal of old windows, besides the installation of new ones?
Is it possible to order windows and doors made of glue-laminated timber, on which no finger joints can be seen on inner and outer sides?
Is it possible to order windows and balcony doors of precious or exotic wood, on which no finger joints can be seen on inner and outer sides?
Is it possible to order balcony doors that open outwards, in case it is not possible to install or comfortably use the inward-opening doors?
Is it possible to order balcony doors with a low threshold, which are more comfortable to use if the actual usage load is high.
Is it possible to order sliding or folding doors?
Is it possible to order extension jambs (usually necessary for log houses)?
Is it possible to order windowsills of glue-laminated timber?
Is it possible to order outer water sills of galvanized sheet as well as aluminium?
Is it possible to install an aluminium cover profile for the windows later, if needed?
Is it possible to order windows of various shapes?
Is it possible to order fireproof windows?
When ordering windows, is the correcting paint included in the set?

Kalesi’s answers for these questions are affirmative as well.

For customers we advise to be informed and consistent in your demands. Kalesi’s team is prepared for all-encompassing counselling in everything window-related.

Eerik Kirs
GSM 56 256 225