Roof Frame Design
Roof Frame Design
One of the most responsible steps of roofing installation is the making of a roof frame. Another consideration is the appearance of the roof. A roof makes the house attractive. There are various styles of roofs:
- Shed or lean to roof- The most budgetary system. The roof rafter system, consisting of one slope.
- Gable roof- The simplest type of roof for a residential building. The gable roof rafter system consists of two planes created by rafters that converge at the ridge.
- Hip roof- The gable rafter system receives two additional slopes. In other words, the pediment is replaced with a roof slope that has a triangular shape.
In the case when a building has a complex shape in plan or a complex layout of the attic space there can be individually designed rafter system.
Roof Rafter System
For a house to serve for many years, to be strong and reliable, it needs more than just a good foundation. An equally significant element is the roof rafter system, which is a roof frame that leans on the supporting structures of the building and serves as the basis for insulation, takes over all the influences of bad weather and withstands loads, heavy snowfall and heavy showers.
There are various materials of roof frames but our company offers you wooden frame because of its advantages:
- Flexibility and Versatility;
- No need for vapor barrier;
- Absence of condensation in the roof (due to the fact that wood reduces the temperature difference between the external environment and the internal space);
- Frost resistance;
- Impact strength;
- Wind resistance;
- Good sound insulation and sound absorption;
- Lightweight material (15-17 kg / m2).
Requirements for the roof rafter system
First of all, each part of the system, as well as the places of joints, must be rigid, without deforming either with shear or with striking forces. The basis of the entire structure is a triangle. This is the shape of the frames (trusses), which are fixed parallel to each other. Their rigid fixation provides the roof with the necessary stability. But if the structure turned out to be movable, it’s not far from trouble. Such a defective roof itself can collapse and also break down the walls.
The roof does not have to be heavy, so the rafter system is usually made of wood. If the weight of the roof is solid, then the supporting base is made of metal. The use of antiseptic and flame retardant components are two required conditions. Then the attachment points of the roof rafter system will be strong and durable.
The main parts of rafter system structure
Analyzing the construction of the roof rafters system, you need to know what parts this system consists of.
- Wall stud is the foundation of the entire system. It helps to evenly distribute the load on the walls.
- The common rafter determines the angle of inclination of the slope, as well as the general appearance of the roof, rigidly fixing the individual elements.
- Purlin holds the legs of the rafters together. The ridge board is at the top, the side purlins are on the side.
- Bottom chord prevents the rafter legs from moving apart, connecting them at the bottom.
- Racks and struts – give the legs of the rafters additional stability.
- Roof battens are attached perpendicular to the common rafters and represents edged bars or boards. It is designed to transfer all the load from the roofing material to the common rafters.
- Ridge board is where two roof slopes meet. A solid roof batten is attached along the ridge to strengthen this part of the roof.
- Eaves are elements designed to protect the walls from excessive rainfall.