When installing rafters for an attic, it is necessary to withstand all the technological requirements so that the supporting structure can fully perform the tasks assigned to it. Farms and other related elements must be mounted so that the finished structure can withstand wind and snow loads for a particular region. All these points are further specified in the calculation process. If desired, the installation of rafters for the attic can be done independently, saving money on the services of third-party workers.
Scheme of rafters.
Attic is a room under the roof, it is located on the attic floor of the building. This technique allows you to correctly plan the growth of used space without significant material costs. In the attic can live no worse than in any other room. But for this it needs to be properly equipped and, in particular, correctly installed rafters for the roof.
The rafter system of the mansard roof.
Before installing the rafters for the attic, you need to select the appropriate type of construction. Rafters can be sloped and hanging.
Suspended rafters for the roof of the attic is best to install in buildings that have a bearing intermediate wall. In order to install a railing system for the roof of the attic, it is necessary that 2 load-bearing walls be located at a distance of no more than 7 m from each other.
If there are no internal walls, the only possible option is hanging rafters for the roof of the attic. The standard design includes rafters and the lower belt - tightening. As a reference element is used mauerlat. For fastening rafters used wire and staples. Installation is carried out with the obligatory consideration of the level of estimated load
Installation of the truss system of the roof.
Before you begin installing the rafters for the roof of the attic, prepare everything you need in the process:
There are several different types of mansard roofing systems, namely:
One of the most important moments of the design is the calculation of the slope angles of the roof. When performing this stage, the following features should be considered:
Fixing units for the truss system.
The greater the angle of slope of the roof, the less free space there will be in the attic. However, if the angle is too small, the roofing system will be harder to clean from precipitation and dirt. Over time, this will reduce the reliability of the system. Therefore, it is very important to choose the best roofing material for the existing conditions.
Correct installation of roof rafters for the attic provides strength and stability to the roof. In carrying out this work, you need to follow a number of rules. First, the construction is constructed from wooden beams with a section of 100x100 mm or 150x150 mm. Secondly, the system is carefully waterproofed. Usually, roofing material or roofing materials are used as waterproofing.
The frame structure is laid on the bases of reinforced concrete. Wire and metal brackets are used for fastening the bearing knot. The thorn-groove connection is often used. It is important that the wood used for the construction of rafters, had a moisture content of not more than 15%. If possible, the choice should be given in favor of conifers.
A disinfectant atmosphere must be created. Damp bars unequivocally prohibited from use. Because of them, the entire truss system can simply collapse. Therefore, before using the bars must be dried. Additionally, the wood is impregnated with antiseptic and anti-fire compounds.
When performing the installation footing markings, count the installation step so that all the rafters are installed vertically in the same plane. Check the vertical installation will help you familiar to any builder tool called plumb.
To ensure the fixing of parts is as reliable as possible, use bracing or stretching. Stand upright studs upholstered with suitable materials. Most often, double-sided plating is performed using plywood and drywall. Between the sheets of plating must be laid insulation.
Scheme of strengthening rafters with additional struts.
The installation process of the truss system for the roof of the attic begins with the laying of the upper beam. To fix it, you can use nails, screws and metal brackets. Bars are used with a section of 150x150 or 100x100 mm.
After that, install the power plate. He needed, above all, to ensure that the roof is not overturned with a strong gust of wind. Mauerlat must be designed and installed in such a way as to withstand the loads that are applied to the roof of the house and its walls. Directly mauerlat is laid out from the bars. It is best to use bars of 100x150 mm. You can also use boards with a thickness of 50 mm.
The selected material should be laid horizontally, having previously calculated the size of the wall surface. Under each bar or board, a waterproofing material must be mounted that will protect the elements of the mauerlat from the harmful effects of moisture.
At the end, the truss legs are mounted. These structural elements can be purchased in finished form or made independently. First, the step of the rafter legs is calculated, after which a marking is applied to the mauerlat. To do this, you need to put marks on the rafter frame and the power plate. Professionals recommend mounting rafters in 1-1.2 m increments. Lay the outer rafters to the front. It is important that the line of the edge of the pediment and the top of the legs are flush.
Rafters are made of bars or planks. It is important that the boards are straight.
It is better to refrain from using the material with knots, the maximum allowable number of knots is 3 pieces per meter.
Types of truss structures.
Next, you need to take the twine and stretch it between the outer rafters. In this case, it will perform the level functions for mounting the remaining legs. In conclusion, you will need to pair up the upper parts of the rafters between them and install the ridge beam. It will be needed if the roof is more than 7 m in length, and the truss frame weighs comparatively much.
If the roof is smaller, it will be sufficient to tie the top of the legs with stretch marks. In the future, you can use stretching directly as attic ceiling beams. With strong wind and snow, these elements will take on a certain part of the load.
At the end, the lathing is installed, moisture insulation and heat-insulating material are laid in, roofing is arranged, walls and ceiling of the attic room are finished.
If there are windows in the attic roof, the work is performed in the same sequence, but at the stage of mounting the rafters window openings are laid into which the window frames will be installed later. Do not forget that the attic should have a size of at least 3x2.2 m. Otherwise, living in such a room would be extremely uncomfortable.
The mansard roof, made in accordance with all the rules, will be a wonderful decoration of any house and will serve for more than a dozen years. Pay due attention to the device trussing system and approach this task with full responsibility. You will not only save money, but you will control every stage of the work, which will allow you to be completely confident in the quality of its implementation. Good luck!
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