What are lattice trusses, where are they used and what are their advantages? One of the basic structural elements of most residential and industrial buildings is the roof frame called the roof truss. Currently, it is possible to make it from prefabricated elements in the form of lattice trusses.
Lattice trusses, also known as trusses or girders, are made of ready-made elements, which after assembly form the basis of the roof structure. What are the advantages of using this type of solution and where are they used?
What are lattice trusses?
Truss trusses are a kind of prefabricated elements from which ready elements of the roof truss are made. Their construction consists of boards forming the upper and lower belts, posts and cross-braces. They are usually made of boards or logs. In the first case, boards with dimensions of 3.8 × 8.9 cm or 3.8 × 14 cm are used. If logs are used, they have a cross-section of 5×10 cm or 5×15 cm.
The individual elements constituting the frame are connected to each other on both sides with overlays made of water-resistant plywood, 1.2 cm thick. More often, however, 2-mm or 2.5-mm thick perforated steel plates are used for this activity. These are galvanized elements designed to be mounted with nails.
It is worth noting that lattice trusses are made primarily of pine wood of class C27. A frequent choice is also high-quality spruce lumber. It is recommended to use wood of class C 35 for the upper and lower belts. Boards made of kiln-dried wood and planed on four sides work best in this type of structure.
It is important that the moisture content of the wood used to create the structure does not exceed 15%. The wood must also be properly impregnated, which will increase resistance to mold, moisture, fire and insects.
The use of lattice trusses
It is assumed that structures made of trusses can be the basis for almost any type of roof, including multi-slope and assuming the creation of an attic. In practice, however, lattice trusses are most often the basis for gable roofs with a non-usable attic. We will find them most often in the construction of farm buildings, residential or industrial buildings.
This is due to the fact that such a solution is easy to install, which saves time and money. However, this does not exclude the possibility of using them for more complex projects. In the case of structures with an attic, these will most often be the so-called mansard roofs.
Advantages of using lattice trusses
The use of lattice trusses has many advantages. The first is the ease of installation and the fact that this solution is very economical. In an easy and quick way, they can be used to create a load-bearing structure for both the roof and the ceiling itself. It is therefore not necessary to create a heavy and expensive concrete ceiling. This solution is easier to implement. Most of the work is done on a flat surface, not at height.
The second advantage is the lightness of the materials from which the lattice trusses are made. Thanks to this, the structure of the building is not additionally and excessively loaded. Another point in favor of their use is to increase the possibility of creating roofs with a larger span. It is possible to build a roof with a span of up to 30 meters.
In addition, this solution does not require the use of intermediate supports. This, in turn, gives a wide field for creating any interior arrangements and layout. This is due to the fact that the trusses rest only on the external walls, which allows the construction of internal load-bearing walls to be omitted in the project. The advantage of using this type of solutions is also the fact that the attic provides a much higher class of thermal and acoustic comfort than in the case of a usable attic.
In addition, the attic space can be used to install an air-conditioning unit or run heating ducts. Staying on the topic of insulation, much less material is used to insulate the ceiling than when you need to insulate the roof slope.
Installation of lattice trusses
Assembling a simple roof structure from truss trusses can take just one day for an experienced team. We can order ready-made and assembled trusses from the manufacturer or try to assemble individual elements on our own at the construction site. The assembly itself should start with setting the trusses parallel to the gable wall and solidly supporting it with boards. A correctly positioned truss is attached to the wall plate.
In the next step, following the guidelines from the design, further trusses are set and connected with the use of boards. It is very important when setting up the trusses that they are properly supported. Improper execution of this step could lead to a domino effect, in which one of the trusses would topple the next ones installed in a row. When the lattice truss structure is already made, it is covered with foil and battens nailed. The base created in this way allows you to lay the roofing material.