Roof fencing - height, gost, device and installation
The roof structure of any structure is quite complex, it consists of many elements that complement each other, increasing its strength, reliability and durability. Experienced roofing masters note that not only the carrying capacity of the roof is important, but also its safety during operation.
Roof railing is one of the most important factors that ensure the safe use and maintenance of roofs, they are mounted on pitched and flat roofs. In the absence of regulatory fencing on the roof, the building can even be prevented from being used. In this article we will talk about GOST, which regulates the installation of fencing, types of parapet and how it will be arranged.
The need for fences
Roof railing is a mandatory element of the roof structure, which ensures its safe operation, repair and maintenance. According to GOST, all roofs must be equipped with barrier structures that protect from the descent of snow, falling from the height of people and objects. The height of the blocking parapet is determined by the type of roof construction, the slope of the slopes and the number of floors of the building. Depending on the type of roof, the fencing of the roof of the building will perform the following tasks:
- On the operated roofs, on the surface of which it is possible to reside, to equip places of rest or even to break up gardens, according to GOST, a parapet is fastened to prevent people from falling from a height. The safety barrier must be high enough to ensure the safe operation of the building.
- Roof rails are also being installed on unexploited pitched roofs. However, its main function is not protection from people falling from a height, but snow retention. The fence, installed along the roof overhangs, helps to keep from falling snow masses that accumulate on the surface of the slope.
Note! The roofing fence with a snow cap can have a various design and a coloring. Most often it is a welded construction of steel pipes or corners, installed along the edge of the overhang. Due to its neat appearance, barrier structures make the operation of the building's roof safer, but do not spoil its appearance.
Fencing functions
Modern building codes clearly regulate the type and height of fences, which should be equipped with a roof depending on its type, slope of slopes and number of floors of the building. Many developers, taking advantage of the ignorance of customers, save on the arrangement of the barrier parapet. However, according to GOST, the construction cannot even be put into operation if its roof is not equipped with fencing of the required height. Roof fencing according to SNiP perform the following functions:
- Prevention of spontaneous descent of snow from the roof slopes. The barriers located along the edges of the overhangs delay or reduce the speed of falling snow sliding down the slopes. This helps to avoid injuries when falling from a roof of snow and frost on a person’s head. Snow-retaining structures are equipped on pitched roofs with a slope angle of 15 degrees. The greater the slope, the more powerful the snow guards should be.
- Ensuring human security during operation, repair or maintenance. The installation of the roofing fence is performed in order to prevent a person from falling from the roof during its maintenance, cleaning the chimneys, installing antennas, repairing the roofing.
- Prevent runoff of water. Fencing a flat roof in addition to the barrier function prevents water from flowing out from its surface, which often causes a blur of the blind area and the foundation.
Interestingly, the metal fencing of the roof can perform not only unitary functions to prevent falling from height during maintenance, repair and operation of the structure, it can be a decorative element that improves the appearance of the building.
Elements of barrier structures
The device of the fencing of the roof depends on the type and nature of the use of the roof, the slope of the slopes, the number of floors in the building, the type of roofing. All parameters of barrier structures are clearly regulated by GOST and SNiP and are applied to the drawing in the building design. The climatic conditions typical for the region in which the construction is carried out have a certain influence on the number and height of the parapet. Typically, the composition of barrier structures include:
- Snow traps. Devices installed at the bottom of the roof overhangs in order to trap the snow mass on the roof slopes. According to their functions, they are divided into snow-cutters, which cut the snow-paste, sliding from the slope, into thin plates, reducing the speed of its fall, and snow-barriers - fences that completely stop the snow. These devices must be installed on pitched roofs along their perimeter or only in places where people are dangerously close to the overhang.
- Transition bridges. These elements are metal walkways that are installed on the roofs to facilitate the movement of staff during the repair of the coating or installation of additional equipment. Transition bridges evenly distribute the weight of a person, preventing deformation of the roofing material, and also serve as a reliable support for the legs on the slippery surface of the slope.
- Roof ladders. Ladders that are attached to the wall and the slope of the roof make it easier to climb to clean it from snow, repair, maintain. In addition, the roof ladder is an additional fire exit that can be used in emergency situations.
Important! Any barrier structures are made from a durable, corrosion-resistant metal. Modern building codes provide for mandatory testing of roofing fencing for strength after installation. In addition, when designing, it is important to take into account the weight of the barriers and the load they exert on the roof frame so that the roof does not deform under their weight.
Barrier Requirements
Fencing of the pitched roof is regulated by GOST. Observing all its requirements, it is possible to make the operation of the structure much easier and safer.. The height of the fencing of the roof, the distance between the vertical supports, the distance from the roof to the lower rail of the parapet depends on the height of the building, the nature of the use of the roof and the slope of the slope, so these parameters are calculated individually and are negotiated by the project. When arranging roof barriers, the following safety requirements are taken into account:
- Roof barriers are mounted on buildings with a height of more than 10 m, if the slope does not exceed 12 degrees, and on buildings less than 7 meters, if the angle of inclination of the slopes is more than 12 degrees.
- The minimum height of the parapet for unexploited roofs is 600 mm, and for those in service - 1200-1500 mm, depending on the height of the structure.
- The distance between the vertical supports of the parapet should not exceed 120 cm, although usually this indicator is much smaller to increase the strength of the structure.
- The distance from the roof to the bottom of the parapet should not exceed 35 cm.
Keep in mind that to determine the suitability for operation is conducted test fencing roof for strength. It consists in imposing in two points located at a distance of 10 m or closer from each other, a horizontal load of 54 kgf is applied for 2-3 minutes. After removal of the goods, the state of the structures is assessed; if they are not deformed, they can be safely operated.
