Construction wood – selection and impregnation

Construction wood – selection and impregnation

Due to its purpose, construction timber must have several important features. As the name suggests, this type of wood will be used for structural elements, especially for the roof truss, which means that it must be durable for many years. When constructing a new building, we have a choice of several types of wood from which the roof frame can be made. Which type of construction timber is the most appropriate?

Properties of construction timber

The skeleton structure plays a key role in the case of the entire roof  . Only the highest quality construction timber should be used for such construction. So what features should be distinguished by wood that can be used to make such a roof frame? The most important features of wood that can be used to erect a roof structure are:

  • high strength and overall durability, 
  • compressive strength, 
  • appropriate hardness, 
  • tensile strength, 
  • no more serious defects, such as knots, 
  • adequate humidity. 

Wood that is distinguished by the above features can be used as a construction material. On the other hand, the use of a material that is of questionable quality and does not have at least one of the above-mentioned features may turn out to be a tragic choice. For this reason, it is not worth saving on wood that is to be used for the construction, because it involves the risk of an accident.

Types of construction timber

We already know the specific features that should be characterized by construction timber . So what exactly types of wood are suitable for use in construction elements?


It is one of the most popular trees that can be used for roof framing. It shows incredible hardness, which is why it finds a lot of supporters among builders. The composition includes a high resin content, thanks to which it is also highly resistant to water and moisture. Interestingly, it is also a good material when you want to make window frames, facade or stairs. In addition, larch will be perfect as decorative terrace boards, because it has an aesthetic grain pattern. 


Another popular tree that can be used to make a frame structure is pine. This species is perhaps the most popular species that is used as construction timber . Unfortunately, pine often suffers from blue stain, so it must be properly impregnated beforehand. You should also remember to dry the pine in the right conditions. Otherwise, it may warp. Pine also works well as a material for door and window joinery and for floors. 


It can be concluded that spruce is the second most popular species of conifers that can be successfully used as construction timber . Spruce requires careful drying and, like pine, it should be properly impregnated. This is especially important when we want to use spruce outdoors. In such conditions, it must be absolutely secured. Spruce also has many more uses. It is also used, among others as finishing wood, e.g. for stairs or floor coverings. 


Fir can also be successfully used as construction timber   . However, compared to the trees listed above, it has a much lower resin content. This means that it must be impregnated much more carefully when it is exposed to external conditions, where it can be exposed to moisture. In addition, fir exhibits the features of considerable elasticity, which may also show a tendency to warp. However, fir also has advantages. I am talking here primarily about high durability and strength. 

As you can see, there are many varieties of trees in Poland that can be used to make the skeleton structure of the roof. However, which construction wood turns out to be the best depends on our individual preferences and possibilities.

How to impregnate construction timber?

Above, in the case of most of the types of wood discussed, we told ourselves about appropriate impregnation. It is an important aspect in the context of the fact that the wood is not exposed to external conditions, such as high temperatures, high humidity or damage related to the interference of fungi and insects.

Impregnation of construction timber at home is simple to perform. Only natural wood should be covered with a special preparation that has protective properties. Apply the preparation with a brush, roller or spray. However, it is worth remembering that for complete impregnation, such activities may not be enough. If we want to thoroughly impregnate construction timber, we should immerse the material in the impregnating preparation for many hours. Thanks to such impregnation of construction timber , we will be sure that it will last for many years.