Natural moisture retention on the surface is a feature of flat roofs. It accumulates due to rains and melting snow. To prevent flooding of the upper floors and stairwells, special devices are used. The roof drainage funnel removes water from the roof in a timely manner, protecting institutions, apartment buildings and private houses, and industrial facilities with equal success.
Purpose of funnels for storm sewers
The main task of the products is to remove liquid from the roof. To do this, a drainage mechanism is installed on the roof, which combines several funnels. They are mounted in a specific sequence, covering the entire surface. Through them, water goes through pipes into the sewer, ravine or ditch, beyond the territory of the object.
Funnels must meet certain standards:
- durable, waterproof contact with the roof waterproofing system;
- sufficient length of the branch pipe to connect to the riser in the attic or in the under-ceiling room;
- a filtration system that protects the pipe from blockages.
Together, these parameters will provide a quick drainage of excess liquid from the roof.
Types and arrangement of funnels
There are many types of storm funnels, grouped into 2 basic categories:
- flat models with lattices;
- cap modifications.
In the first case, installation is carried out on monolithic roofs without a sand layer. The lattices are made in the form of cells, squares, ovals, etc. All storm water runs on top, so the grille is at or below roof level. Debris is protected by a galvanized mesh, umbrella or inner cone.
The bell structure includes the funnel itself, an inner umbrella, a bell (glass and lid). The edges are equipped with special teeth that clamp the roofing material tightly adjoining the surface. There are ribs inside that open a small gap for water to drain. As a result, leaves, paper and other debris do not enter the pipe, preventing blockage.
Manufacturing materials
When choosing a material, property owners and specialists are guided by its ability to withstand moisture. Because of this, preference has long been given to cast iron and galvanized steel. They are also widely used today, but are largely replaced by plastics, which have proven to be effective.
- Cast iron monolithic models. A common version, adapted to the tight clamping of the roll surface. It forms a waterproof carpet, quickly removing excess moisture. Also, cast iron is in demand due to its decorative properties - the bell structures created from it look representative.
- Steel modifications. A reliable option for both lattice models and hoods. The funnels are made of semi-boiler, asphalt, galvanized iron, which guarantees a long service life and protection against corrosion. The operational properties are practically not inferior to cast iron, while steel is much cheaper.
- Plastic option. Differs in increased practicality and ease of installation. Such structures are better able to withstand moisture, temperature and other environmental factors. The service life is not limited, and the price is much lower, which is especially important when completing industrial facilities.
The choice of material is determined by the characteristics of the object, including its area, appearance, aesthetic requirements.
Features of installing roof outlets
The installation of structures, their number and the interval between the funnels depends on the characteristics of the object: area, configuration, rain volume and other parameters. In practice, the distance between 2 elements is about 25 meters, which is enough for timely drainage. Fewer quantities lead to clogging of the funnels with subsequent accumulation of liquid on a flat surface.
All components are connected to downpipes, and a back-up system is formed in case of overload. It is activated when the spring snow melts, heavy rainfall or during prolonged rains. In this case, it is important that the receiving part does not become clogged.
Installation is carried out in several stages:
- The inner element is inserted into a special hole in the roof. The fasteners should not be rigid.
- The outer part is inserted from above, passing it through the roofing carpet and insulation. A sealing ring is placed between the 2 elements.
- The apron of the hood is installed on a roofing felt lining and an additional waterproofing layer.
- A roof covering is inserted into the funnel bowl, which is fixed with a ring and fasteners.
- The process completes the installation of the protective grille.
Success is determined by competent work planning and the qualifications of specialists.
