Do-it-yourself installation of truss system - how to do it

Roof installation is a complex technological process, which includes the design, assembly of the frame, the laying of the roofing material and the installation of auxiliary elements. Although it is not easy to construct a roof correctly, in order to reduce the cost of roofing work, if you have basic building skills and tools, you can do it yourself. In this article we will describe in detail the sequence of actions necessary to independently carry out the installation of the roof system of the roof of a private house.

Rafter frame and its functions

The roof frame of the roof is the set of wooden elements that form a kind of "skeleton" of the structure that supports the roofing slopes, giving them the necessary shape. If desired, the truss system can be made by hand, the main thing is to correctly calculate the loads and determine the composition of the structure. The functions of the roof frame are:

1. Support roofing ramps. Rafter legs give the surface of the roof slopes a slope that is necessary for melt or rainwater to be effectively removed from them, and snow masses on their own.
2. Roof weight distribution. Properly designed frame construction evenly distributes the weight of the roofing pie to the bearing walls and the foundation of the structure, preventing deformation and subsidence of the supports.
3. Place for fixing roofing material. Those who at least once with their own hands blocked the roof, know that the crate of the frame serves as the basis for fixing the waterproofing coating.

Note! The rafter frame is made of wood or galvanized metal. The choice of material depends on the cost of roofing, service life and the carrying capacity of the roof. Experienced craftsmen believe: if the length of the slope does not exceed 6 meters, it is much more rational to make these elements from wood.

Project creation

Before you make rafters for the roof of a private house with your own hands, you need to create a working design project that takes into account the climatic conditions in the area where construction is underway, the way to use the attic, as well as the type of roofing. All these factors are taken into account in calculating the loads that affect the roof frame. To determine the required bearing capacity and create a roof project, it is necessary to determine:

• The cumulative load on the rafters. For this, permanent loads (the weight of the roof system itself, insulation, roofing material and waterproofing) are summed up with temporary loads (snow, wind and elemental loads). The total weight of the roofing pie when using thermal insulation can reach up to 700 kg.
• The height of the ridge roof. This indicator is calculated based on the desired slope of the slopes and the width of the overlapped structure. Also at the height of the ridge affects the way to use the attic: if it is equipped with a residential attic, the ridge should be located not less than 250 cm from the floor.
• Slope ramps. The angle of inclination of the roof slopes is calculated as a quotient of the ridge height and half the base of the roof. This factor depends on the climatic conditions in the region of construction, as well as the characteristics of the roofing material.

Important! The result of the calculation of the total loads, the height of the ridge and the slope of the slopes is a well-designed, detailed scheme of the truss frame, which will facilitate the manufacture of the structure with your own hands, as well as reduce the risk of errors.

Selection and preparation of material

To make a strong and durable truss frame for the roof of a private house, use solid wood or metal profiles. The final cost, weight, service life and carrying capacity of the finished structure depend on the choice of material. To work with their own hands experienced craftsmen recommend choosing wood. To rafters served for a long time, it is necessary to check the conformity of lumber to the standard:

1. The moisture content of sawn timber used to make rafters with your own hands should not exceed 19-21%. Wet wood in the process of drying can crack, warp, because of what there are deformations and distortions in the roof.
2. The tree must be in a healthy state. That is, it should have a light color, characteristic of the breed, not have pockets of rotting, mildew, browning or traces of pests.
3. For the manufacture of rafters, it is recommended to choose straight, flat boards without a large number of knots, since they reduce the strength of supports.

Take into account that the wooden truss frame has served for a long time, before starting construction work on the structure with their own hands, they will process the deep-penetration components with an antiseptic, and to reduce the number of firefighters, the fire-blocking compound is impregnated.

Bookmark booklet

The installation of the truss system of a low-rise house begins with a bookmark of the mauerlat. This term refers to a support bar, which is mounted on the top pillar of the load-bearing walls where the roof slope rests on them. The number of master bars used in the design always coincides with the number of skates. Mauerlat is made of a thick wooden bar with a thickness of 10-15 cm. The laying of this frame element is carried out in accordance with the following rules:

• Mauerlat is mounted only if the box of the house is made of brick, concrete, gas silicate, foam block. In wooden buildings, the role of the Mauerlate is played by the upper crowns of the frame, firmly fixed with metal brackets or pins.
• Some types of wall-mounted truss systems do not provide for installation of a mauerlat, since they do not exert a bursting load on the walls of the structure.
• Between the wall of the house and the mauerlat always put a solid waterproofing to prevent condensation settling or wood rot. For these purposes, asphalt, roofing material or roofing felt.
• It is not allowed to perform a tie-in under the rafter legs in the mauerlate, since each violation of integrity reduces the strength of the beam.
• The fixing of the power beam is performed with the help of studs embedded in the wall of the house, or with long anchor bolts.

Do not forget that before installation, it is advisable to treat the antiseptic with deep penetration to prevent rotting of the wood, and also to soak it with a flame retardant to protect the roof frame from fire.

Assembly technology

The degree of complexity and the sequence of assembly of the roof frame of the roof depends primarily on the design and type of rafters. In order to do the installation yourself, it is better to choose simpler dual-slope structures. If load-bearing walls are provided inside the house, then an overlay truss system can be used. The frame is assembled in several stages:

1. Bookmark booklet и лежня. На этом этапе важно прочно зафиксировать опорные брусья вдоль несущих стен металлическими шпильками или анкерами.
2. Vertical racks with a pitch of 1.2-1.5 meters are installed on the bed laid on the inner bearing wall. That they kept upright position, establish temporary props.
3. On top of the rack stack ridge girder. It interconnects vertical supports and serves as the basis for the installation of rafter legs.
4. Mount truss legs. One end of the rafter attached to the mauerlat, and the other - on the ridge girder.
5. Perpendicular to the rafters they nail the crate on which the roof covering is laid.

Remember that you can block a wooden house with your own hands only after complete shrinkage of the box. To compensate for the change in the geometry of the roof, apply a mobile mount, adapting to the size of the house.

Video instruction