Choosing a project home, the future owner pays attention to the Foundation, walls and roof structure. But not less carefully it is necessary to treat the soundness of the frame, are affected by all load burdens.
The unit truss system is difficult, because the roof needs to comply with possible loadings and fully comply with them. From a balanced approach to its construction and quality of materials varies a lot - endurance design, safety and attractiveness of the structure.
Sometimes the roof is too complex in its structure - contains a variety of slopes and bizarre twists. In this case, it is not the owner of the property presumptuous to expect to do without professional help.
If you look in the private sector of the roof of the houses already built, make sure that the most popular is considered the gable roof, in view of the simplicity and more reasonable prices. But, without understanding the nuances of the construction of the frame, clearly presenting all the elements of the truss system and their purpose, you can handle the work independently. Or, if the work is too difficult, check the integrity of employees.
Truss system and its basic elements
Truss system - the basis of any pitched roof type. Every detail should be as durable as the joints - hard and not subject to deformation.
Considering the structure of future roof, you need to submit the components of the roof system and know about the functions they should perform. Whatever kind of design a was selected, the device consists of rafters of the same elements in different configurations of the connection:
- mauerlat - it can rightly be called the basis of the whole structure of the rafters. The appointment of a beam of square section is to evenly distribute the load on the bearing walls;
- truss legs - bars, which will be responsible to withstand the vicissitudes of weather the aggression and heaviness of the whole structure. The most important elements of the truss system of the roof support and protect the roof from possible deflection under the influence of the snow cover. The distance between the rafters, the so-called step, is usually 0.6 to 1.2 meters and depends on the weight of the roof and its structural features;
- the girder and tightening - holds the first rafter and the second does not allow them to disperse, connecting the lower ends;
- the struts and strut - designed to increase the stability of the rafter. Stand assumes the vertical load and must rely on a support structure, the brace - protects the rafters from the trough;
- the sheathing - boards are fixed to rafter feet at a right angle and transferring the load of the roof, at the same time more securely attach them. Sometimes, if elected soft look of the roof, for the manufacture of crates use moisture proof plywood sheets;
- wind beam - an additional guarantee of stability of the truss to the influence of wind or other loads;
- filly is attached to the rafter leg to form the eaves of the roof, which protects the wall structure against rain.
- groundsel - reliable support and dispenser rack loads on a larger area.
Design future home and its parameters determine the decision on the election of the type of roof system.
Principal roof and the rafters to give preference to
The choice of the shape of the roof is wide enough, and the results determine the use of any form of rafters:
- Shed - a simple device with a tilted angle of 14-26° slope.
- Gable (gable) located underneath a loft or attic space. The most popular and quite simple design. The angle is usually 14-60.
- Hipped (hip) is the slope varies in the range of from 20°to 60°, the installation presents certain difficulties;
- Sloping (attic) is usually sloping top and with a slope up to 60°down.
To the Assembly of the rafter system was executed flawlessly, you need to choose its type among the two possible - naslonnye, hanging.
Its name naslonnye rafters received by way of the location, "laying out". A feature of the construction is that the rafter legs using intermediate supports, its use is only possible in the presence of internal load-bearing walls (a shed roof span should be small - up to 6 m, otherwise also need support).
The number of control elements is determined by the size of the house and the section of the rafters. Such a device is not too heavy and requires fewer materials and, therefore, more profitable. Applies, if the span of roof is less than 16 meters. For naslonnye rafters is only the bending effect.
Heavier hanging rafters convenient for gable roofs with a span up to 6 meters in the absence of load-bearing walls. The ends of the rafters are based on mauerlat or wall at the bottom and each other back to back, often with the help of ridge run at the top. Sometimes possible combined design.
For hanging rafters is due to the design compressive bending and impact, in addition do rafters with great force putting pressure on the walls horizontalno, which use a puff to reduce such pressure.
The secrets of choosing material and how to choose the size of the rafters
The lighter the roof, the less strain it has on the house. Therefore, as a material for roof system using wood. Only in the case of the roof, apply a metal carrier framework. The choice of wood should be approached responsibly, the minimum permitted number of cracks and knots.
Important! If wood moisture content exceeds 18 %, to connect the elements of the design better, not nails, and bolts. Otherwise, after drying, the truss system may become shaky.
Usually in the construction the use of design of rafters from boards 50х150 mm or mm. 60х200 If you select a heavy roof covering, like ceramic tiles, the cross section is allowed to increase.
The main material of the construction elements are softwood wood boards for the rafters can be up to six and a half meters. For products from deciduous trees not exceeding 4.5 m. it is Very important that before installation, the wood has been treated with bioprotective means and antiseptics.
Determine the required size of the rafters is quite difficult. If the length can be calculated by using online calculator roofs, the correct choice of thickness and cross-section is influenced by many factors - the angle of slopes, temporary loads in the form of precipitation, the weight of the roof, the likelihood of deformation and a variety of other indicators.
Use the calculation of a gable roof on our calculator, which will help you to determine the consumption of materials and sizes and parameters of the roof, its elements, will also prepare for you a drawings, 3D visualization. Offer free calculators roof for Gruga types - shed, gambrel, calculations of the rafters and so on.
With the basic principles offers to see the article the Calculation of the rafter system. You can use special tables, but the best solution is to entrust the calculation of the size of rafters for a roof professionals.
Even if you feel strong enough to cope with the installation of a complex roof system yourself, use the services of professionals for its design. Because the durability of the structure, security and comfort in a fierce storm depends on the proper construction of the roof of your home.