What are roof trusses?

Ostania aktualizacja 4 December 2019

It is first of all important to be aware that the approach to the roof as a supporting structure characterized by a certain steepness is only partial. It should be realized that from the practical side the roof, apart from the internal finish, also consists of internal elements. The most important of them are roof trusses . The task of these products is definitely the most important. They support both the weight of the roof and everything that is on it. It is important to note that roofing technology based on roof truss structures is becoming more and more popular every year. However, not everyone is aware of exactly what this technique is all about, because it has undergone numerous modifications in the last few decades.

Roof trusses – what is it?

Roof trusses for the framing of a family home are among the most basic load-bearing elements of the roof structure. Their tasks include transferring load between the roof and the rest of the building. It is worth knowing that roof trusses are used almost everywhere. They work perfectly well above all for roofs with a very large surface and span. This way you can reduce unnecessary support points.

It should be mentioned that regardless of the design and application, the upper and lower straps will be the basic element of roof trusses. They provide excellent support for various types of cross-braces and posts. Diagonals are diagonal elements that work perfectly above all for roofs with a small drop angle. In turn, posts are vertical elements that directly support the external structure of a given roof.

The aforementioned posts and diagonals in the vast majority of cases fastened with straps via gusset plates. It must be emphasized, however, that this is not the only way to fix them. Individual elements of wooden trusses should be connected with nodes. Of course, due to the different types of loads that the roof is subjected to especially in winter, the said connection should be characterized above all by excellent strength parameters, as well as very low susceptibility to ambient temperature. It is also worth noting that the roof truss for a single-family house is usually made of wood. In addition, steel or reinforced concrete can be used interchangeably. In both the first and second cases, not only load-bearing walls must be used, which will withstand various types of overloads, but also definitely more durable foundations.

Where are wooden trusses used?

It is worth knowing that currently truss technology is used primarily for the construction of roofs characterized by increased resistance to external influences. It should be noted that the high cost of technology means that it is not popular in countries where there are relatively high average temperatures. It is also worth mentioning that the most important factor that will determine the use of this technology is snow. Unlike rain, it cannot be removed from the roof surface so easily. In addition, during the snowmelt, the snow will definitely increase in mass. Wind is another factor that is a direct threat to the integrity of the roof. You have to be aware that, unlike the snow mentioned above, it has a much greater impact on roofs characterized by high steepness. Due to all these factors, roof trusses must be used primarily in moderate climates, i.e. the United States, Australia and Western Europe. In turn, due to the relatively high costs of their implementation, as well as very adverse weather conditions, the structure in question is not used in Asia and eastern Russia. Of course, this trend may change due to climate change in the near future. It is worth knowing that cheaper prefabricated structures are appearing on the market.

Roof truss – what is worth knowing about it?

The technology of prefabrication in recent years has made a huge revolution in the construction of both single-family and multi-family houses. Of course, the method of building a roof based on prefabricated elements is not as popular as the construction of load-bearing walls, but it can be seen that from year to year it is becoming more and more popular. The roof truss, just like in the case of a traditional truss, consists of very important elements that not only have specific names, but also perform specific functions. These are:

– wall plate

– rafter

– purlins

– claws

– strut

– wreath

Wood Certification

It is necessary to pay attention to the fact whether the wood that will be used to build the truss will have the appropriate certification. It is the legal basis that will confirm whether wood has significant properties.