For a rebuilt house to serve for many years, being strong and reliable, it needs more than just a good foundation. An equally important element is the roof restoration rafter system, which takes over all the vicissitudes of bad weather. And it must with honor be able to withstand the loads in the form of gusts of wind, heavy snowfalls and heavy showers. Let's talk about how this system works and how to properly build it.
Requirements for the rafter system
First of all, every part of the system, as well as the joints, must be rigid, not deforming either under the shear force or under the thrust force. The basis of the entire structure is a triangle. Frames (trusses) have this very shape, which are fixed parallel to each other. Their rigid fixation provides the roof with the necessary stability. But if the farms turned out to be mobile, it is not far from trouble. Such a defective roof restoration itself can collapse and collapse the walls.
The roof doesn't have to be heavy, so the rafter system is usually made of wood. If the weight of the roof restoration is solid, then the supporting base is made of metal. Or take a coniferous tree, not lower than the first grade, with a moisture content below 18 percent. The use of antiseptic treatments and the use of flame retardants to protect against fire are two prerequisites. Then the attachment points of the roof truss system will be strong and strong.
High quality material
The tree for the rafters should be as follows:
- Wood is taken from 1 to 3 grades. Cracks and knots should be kept to a minimum. There can be 3 knots per meter, no more than 3 cm high. Cracks are not allowed along the entire depth, up to half the length of the board.
- Bearing elements are made of wooden parts with a thickness of 5 cm and an area of 40 cm 2 .
- Coniferous boards can be up to 6.5 m long, and deciduous boards up to 4.5 m.
- Runners, pillows and mauerlat are made from hardwood. They are treated with an antiseptic.
The main parts of the structure of the rafter system
Thinking over the structure of the roof rafter system, you need to know what parts this very system consists of.
is like the foundation of the whole system. It helps to evenly distribute the load on the walls.Mauerlat
determines the angle of inclination of the slope, as well as the general view of the roof, rigidly fixing the individual elements.The rafter leg
- holds the legs of the rafters together. The ridge girder is at the top, the side girders are on the side.Girder
- prevents the rafter legs from moving apart, connecting them at the bottom.Tightening
- give the rafter's legs additional stability. They rest on the bed (which lies at the bottom parallel to the ridge).Racks and struts
- stuffed perpendicular to the rafter legs and represents edged bars or boards. It is designed to transfer all the load from the roofing material to the rafter legs.Lathing
is where two roof slopes meet. A solid lathing is stuffed along the ridge to strengthen this part of the roof.The ridge
- used to create an overhang if the length of the rafter legs is not sufficient.Filly
is an element designed to protect the walls from excessive rainfall.Roof overhang