Drainpipe for flat roofs - device and installation

The main enemy of any roof is water, the destructive action of which leads to a reduction in the service life of the roofing material, leaks. Double-slope, hipped and even single-slope roofs have something to counter the thawed and rainwater. These are their slopes, thanks to the slope of which the moisture, not lingering on the roof, slides down. Flat roofs are less protected, puddles accumulate on a flat surface and do not have time to dry.

Water stasis methodically destroys the waterproofing layer, in addition, the dust applied by the wind accumulates in them, forming a marshy substrate. Plant seeds trapped in this "soil", germinate and destroy the roofing pie roots. To avoid extending the service life, flat roofs are equipped with a drainage system that drains water from its surface into the storm sewer.

Flat roof drainage system

Flat roof drainage system — совокупность элементов, осуществляющих сбор, перенос и выброс воды, оказавшейся на поверхности кровли в результате выпадения осадков или таяния снега. Водосток с крыши оборудуют следующих видов:

1. Unorganized. It lies in the fact that the water just slides off the steep slopes. This method of self-draining is used in private houses with pitched roofs, but not suitable for structures with a flat roof.
2. External. Consists of fixed on the wind dock or rafters gutter and drain pipes. By gravity due to the slope of the roof, the water is removed from the slopes and drained into a drainage drain or shower. External drain is used to discharge water from a flat roof of a small area, in particular, for economic structures.
3. Interior. A characteristic feature of the internal drain is that it is laid inside the roofing pie. It is designed to meet the specifics of a flat roof.

Internal drain flat roof

Internal drain flat roof размещают не снаружи, а под слоями гидроизоляции, утеплителя. Он состоит из:

• Gutters funnels installed on the surface of the roof, in low places, built with the leveling. Funnel function - collecting and filtering melt and rainwater falling on the roof.
• Horizontal drainpipes, which are installed under a layer of waterproofing and insulation under a slope, if gravity drainage is installed or without a slope, if vacuum.
• Vertical drainpipes that collect water flows from horizontal pipes and drain into storm sewers.

According to the method of movement of water in the drainage system is gravity and vacuum type. The principle of operation of the vacuum drain is that the precipitation completely fills the pipes, creating a water column, when moving down, the air rises first up, creating a vacuum environment, and then carries the water out of the drain funnel, as if sucking it. In areas with heavy showers, experienced roofers recommend installing a vacuum system that copes quickly with a large volume of water, and even self-cleaning due to its rapid movement through pipes.

The design of the drain funnel

The drain on a flat roof meets the collection and reception of water accumulating on the surface. It consists of:

• The lower part, which is mounted in the base of a flat roof.
• Seal, hermetically connecting the upper and lower part of the drain funnel.
• The upper part, passing in the thickness of the insulation and waterproofing.
• Protective grille, which is located above the roof surface and protects the drain funnel from the penetration of large debris and the formation of blockages.

The tightness of the connections between the elements of the drainpipe - a prerequisite for the effective operation of the drainage system. When examining a flat roof after detecting a leak in 70% of cases, the problem was water penetration between the joints of the funnel parts.

Types of drainpipes

Roof drainpipe can be made of galvanized metal, copper or polyvinyl chloride. Copies of galvanized use more often than others, thanks to the affordable price. Copper funnels, due to transcendental cost, have not gained popularity, especially since they are not combined with all roofing materials. Products made of polyvinyl chloride are excellent for mounting on soft tile, shinglas, unduline.

In specialized stores there are the following types of drain funnels:

1. Kolpakovye. Understand that in front of you kolpakovaya funnel, will help the protective mesh, resembling a cap or glass, towering above the surface of the roof. It not only copes with large flows of water, but also filters it from large impurities, preventing the drain to clog.

   

2. Flat. The funnel, installed at the level of the roof surface, is mounted on operated flat roofs, covered with tiles or asphalt.
3. Heated. Such a funnel is heated by a thermal cable installed in it, heating the snow, preventing the formation of an ice crust that prevents the drain.

   

4. With vertical or horizontal release.

Rules of installation of drainpipes

Establishing drainpipes, professional roofers adhere to the following principles:

• Place the craters in places located below the main level of the roof. The slope between the base and the funnel should be at least 2 degrees, and at a distance of 50 cm to increase to 5 degrees. Slope set when razuklonke insulation plates, expanded clay or concrete.
• Water drain funnels are distributed evenly over the surface of a flat roof at the rate of 1 piece per 25 meters length.
• Regardless of the roof area, the minimum number of drain funnels is two. As in the case of clogging of the drain or during heavy rains, the second will insure a funnel that is out of order or cannot cope with a large volume of water.
• The smallest allowable distance between the funnels drain - 50 cm. And from the edge of the roof - 1 m.

Installation Procedure

Install the drain funnels on a flat roof as follows:

1. The surface of the roof is divided into geometric forms of equal area, organizing a slope to the center by filling claydite, insulation or pouring concrete. In this case, the lower part of the funnel is installed in the base of the roof, connecting it to a horizontal drain pipe.

   

   

2. After laying the insulation and waterproofing connect the upper part of the funnel with the bottom, using the ring seal.
3. A plastic apron, which is on the upper part of the funnel, is placed between the upper and lower layers of roofing material and secured with an apron bitumen fused.

   

4. Next, cover the roofing cake with mastic or bitumen for the roof and establish a protective grid.
5. They check the tightness of the joints and the effectiveness of the drain with a simple check: at a distance of 2 m from the funnel, a bucket of water is thrown out and it is observed how quickly and if it falls into the drain.

The drainage system, including the funnels, must be periodically inspected and cleaned so that unexpected rainfall does not lead to the collapse of the roof. Properly organized drain will not only prolong the life of the roof, but also become a source of water for irrigation, if you are concerned about the conservation of natural resources.

Video instruction