Rafter system: all types and schemes (85 photos). Choosing the optimal roof option for a private house

The roof serves as a reliable protection of premises from various natural phenomena. It is a basic element in the construction of a private house. The truss system is a load–bearing roof frame, which is assigned a lot of weight and load: wind, snow, frame. In order to avoid troubles during operation, the roof must be reliable and strong.

The truss system is the basic part of the roof, it affects the strength of the roof itself, resistance to weather changes. The design is influenced by the shape of the roof and the plan of a private house, as well as the details that will be used.

The rafter system, which they perform themselves, is most often made of wood, but sometimes other roofing coverings are also used. Before starting the installation of the truss system with your own hands, you need to prepare well theoretically.

Summary of the article:

It is very important to distinguish between the words "roof" and "roof". Roof — consists of rafters, roofing, insulation parts, encloses the house from above. A rafter is a beam that creates a slope, a supporting system of a pitched roof.

The roof is the upper shell of the roof, which is made of various building materials. The reliability and practicality of the operation of the house depends on the roof.

System Requirements

For effective mounting of the truss system, it is necessary to act according to certain norms, without which the structure will not be practical.

Particular attention should be paid to the strength of the system, which must withstand a full load. To check the truss system for strength, an approximate calculation should be carried out.

The second condition is rigidity. The roof system of the building should not bend much. The rafter system should not have a large weight, the load on the foundation and walls should be minimal. As a base material, wood is most often chosen because it is relatively lighter with other materials and sufficiently durable.

Also an important feature is the choice of material for the roof, which should not be heavy. Now less and less often choose tiles, which are made of ceramics. Under this material, all elements of the structure of the house should be well reinforced.

The wooden structure is made only from high-quality raw materials. For the manufacture of basic elements, a tree of 1 or 2 grades is used. Coniferous wood is most often used for the installation of pitched roofs. This type of wood contains resin, so it rots less.

Be sure to use antiseptic before starting work. This will help to avoid various troubles. Most often they buy wood in the northern regions. It is this kind of wood that is considered the best.

Elements of the roof truss system

The structure of the truss system consists of various elements. The main components of the roof are: slopes, cornice and ridge. The top element of the roof is a ridge. Overhang (cornice)- this is the lower element, and the ramp is located between the cornice and the ridge. Also, the supporting elements belong to the rafter system.

The bearing elements of the truss system include:

Mauerlat is the basis for fixing the rafters, it is laid along the perimeter of the walls. It is stacked so that the load is uniform. For the manufacture of the mauerlat, a 20cm * 20cm or 15cm * 15cm beam is taken (for small structures).

Inclined beams, with the help of which the load from the roof, wind and snow is transferred to the structure of the mauerlat are rafter legs. They are most often mounted from the ridge to the cornice.

The beam on which the roof parts rest is a girder. The diameter of the girder is affected by its span, most often 20 * 20 cm is taken.

Also, the roof system wooden roof includes: struts, rack and tightening. Their main function is to reduce the severity of the underlying elements.

The truss is also an element of the truss system. The structure of this structure includes: puffs, rafters, racks, struts. The farm is built in the shape of a triangle, so it has good stability.

The connection nodes of the rafter system are of the following categories: the connection node of the mauerlat and legs, the connection node of the elements of the wooden truss and legs.

The method of connecting the mauerlat and the rafters is sliding and rigid.

It is not always possible to apply rigid angles, because from the influence of the environment, wooden elements are deformed and it is not always appropriate to apply a rigid coupling of the floor systems.A system of sliding angles is used for the construction of slatted rafters.

The presence of a drawing of the truss system, where all the structural elements are indicated, will effectively help in working on the system.

The drawing is presented below.

Roof shapes

The roof on pitched roofs can be of such forms:

single - pitched;
double - pitched;
hip;
polylines.

With a single-pitched roof truss system, the simplest construction is made, its slope is 14-26 degrees, here the slatted rafters are supported by load-bearing walls.

The roof in the gable truss system should be with a slope of up to 60 degrees.

The roof with a hip roof truss system should also be at an angle of up to 60 degrees. This type of roof is more difficult to install, but the cost will be much lower since there are no front walls. For the installation of a hip roof, truss trusses or slatted rafters are used.

With a mansard (broken) roof shape, the span is made 10m, and the lower roof area is located at an angle of 60 degrees, thanks to this you can increase the size of the attic. The span between the outer walls, according to the recommendation, is not more than 10 m.

The differences between the roof shapes are shown in the photo of the rafter systems in the gallery at the end of the article.

For the construction of mansard roofs, connections of parts are most often used. The main functions that the connections of parts perform:

ensuring load transfer in the right direction
withstand physical exertion
providing a guarantee of operation

At the moment, such building materials are used to connect elements in the rafter structure: studs, metal linings, bolts, self-tapping screws.

For fixing parts that are made of raw wood, studs or bolts are most often used.

Roof ventilation system

Streams of water vapor very often pass from a warm room to the attic, which creates condensation on the roof coverings. Wooden parts and insulation suffer from condensation.

Ventilation is done to eliminate moisture in the rafter system and in the attic.

The water vapor that gets into the attic should go out without obstacles through the windows and special holes that are made in the roof ridge.

In houses where flat roofs and attics are used, there should be a space with ventilation.

Laying of the roof covering

Pitched roofs are covered with rigid (asbestos cement sheet, polymer or ceramic tiles, profiled flooring, etc.) or soft materials (bitumen shingles). Most often, rigid materials are mounted on a wooden frame.

Rigid sheets of roofing are most often laid on a crate made of wooden bars

When installing each truss system with your own hands, you must firmly mount all the nodes and connections. It is important to make not only the right frame, but also to choose a practical material for the roof. The roof is the most important protection of the house from various bad weather.