Flat Roofing Installation Near Me

FLAT ROOF

In fact, flat roofs are not like that at all. The slope of the roof is to be not less than 3 °, usually up to 11 °. The slopes can be directed outside or inside the building. The smaller they are, the better waterproofing should be used. Rainwater drains faster with a greater fall, and less dangerous is also the residual snow and water that forms when it dissolves.

A flat roof is both a roof and a ceiling, hence the name flat roof. Roofs are often used in the designs of modern houses, more and more often chosen by investors. They have several advantages: unlike sloping ones, they allow you to use the entire area of ​​the upper floor, and if the plot is too small, you can arrange a garden on a flat roof. Depending on the structure, flat roofs are divided into ventilated and non-ventilated.

It is the most popular flat roof, somewhat similar to a sloping pitched roof. The ceiling is the load-bearing element. The supporting structure of the roofing is based on it, which is most often made of wooden elements – trusses or prefabricated trusses, or of metal sections. The fallen layer is made of wood-based materials – OSB boards, plywood.

The cover can only be made of highly airtight material – usually it is a bituminous felt laid in several layers. In this solution, a void is left between the covering and the insulation installed on the ceiling. The moisture that appears there is discharged through the ventilation holes in the knee walls (these are the outer walls between the ceiling and the roof slope).

You must remember to protect these openings with a net that will prevent birds from getting into the attic. The insulation installed on the ceiling is made of polystyrene or mineral wool, and there should be a vapour barrier underneath it. Rainwater is drained from flat roofs by gravity or under pressure, although this option is practically unheard of in Polish single-family houses. In the most popular variant, rainwater is drained through the attic culverts, then through external downspouts.

It is usually flatter than the ventilated variant, and its structure differs significantly from other roof structures. There are no trusses or voids here, the roof is simply a reinforced concrete slab. All layers (construction, thermal insulation, waterproofing) fit tightly together. The necessary slope is formed by pouring (on the vapour barrier) a slope made of concrete, or by placing a reinforced concrete slab on a sand or LECA ballast.

Non-ventilated roofs are insulated with polystyrene (minimum roof/floor) or wool in the form of plates. You can also use hard polyurethane foam boards covered with roofing felt on one side and a vapour barrier on the other. A non-ventilated flat roof is easy to make but has a serious drawback. Water vapour from the house can collect under the cover and cause it to become damp. To prevent this from happening, the undercoat under the cover may have small channels running along the slope of the roof. This variant is called a non-ventilated flat roof, ventilated.

Non-ventilated roofs are also made in an inverted system of layers. In the traditional version, the roofing made of tar paper is exposed, for example, to large temperature fluctuations or mechanical damage. In an “inverted” roof, waterproofing (two layers of heat-weldable roofing felt) is first laid on a ceiling with a shaped slope, and on it insulation resistant to permanent moisture (extruded polystyrene). The geotextile is spread over it, on which the pressure layer is placed, e.g. a gravel topping. Rainwater is collected by the drainage system from above and below the insulation. You can even set up a garden on such a roof.