Roof truss is one of the key elements of house construction. The appearance and solidity of our roof depend on it. Usually the design of this element is already created together with the other parts of the house but sometimes it requires further elaboration by specialists who will precisely calculate how many and which elements we will need. And among them we will find, among other things, roof rafters. How to choose the right ones?
When choosing wood for the roof, first of all we must remember that it must be properly prepared. Sometimes you can hear voices saying that wood straight from the forest is also perfect. Nothing could be further from the truth. Appropriate wood, which is ready to work, should be dry and seasoned, otherwise during natural drying various deformations may occur, which will require replacement of newly installed sheathing and defective elements – and thus additional costs. The best species for roof rafters are pine, spruce, fir or larch. The last one, although the most durable, due to its high price is rarely chosen.
What are rafters?
Roof rafters are the basic element of roof trusses. They are usually wooden beams supporting the whole roof structure. They carry the load and support the roof elements attached to them, mainly the sheathing. The safety of the building and people living in it depends on them. The stability and strength of the roof also depend on them, that is why during the selection we have to pay special attention to their quality, size and cross-section. On the market there is also prefabricated rafter framing available, where it is the computer that calculates all necessary dimensions according to the plan. These are steel rafters, which can be covered with wood cladding or boards.
By definition, rafters are sloping beams with a rectangular cross-section, whose task is to maintain the rigidity of the roof truss, as well as the roofing that rests on them.
Their choice is also dependent on the type of roof we plan to build – for example mono-pitch, gable, multi-pitch or flat.
Roof rafter types
We can distinguish five basic types of roof rafters which perform specific functions in the roof truss and their occurrence depends on the type of roof we are erecting, and these are
- main rafters – the most important element of the rafter which transfers the load to lower parts and elements of the building, they form the arms of the carpentry truss;
- front rafters – they support the main rafter in case of double or multi-sloped roofs;
- valley rafters – they support the valley of a multi-sided roof;
- Corner rafters – support the corner ridge in multi-pitched roof construction, they are also called tie rafters;
- Beehives – also used in multi-pitched roofs; they are shorter rafters based on corner or valley rafters.
Price of roof rafters
The cost of roof rafters depends on their dimensions as well as the type of wood they are made of. However, it is an element on which we should not economize. Although choosing too small sizes will lower the price but in the later use it may turn out to be dangerous for the inhabitants, especially when we create a multi-pitched roof. It is also important their number and placement, which should be in accordance with the plan and calculations made by a specialist with proper authorization.
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