Flat Roofs And Rain

The risk of rain although called a flat roof a flat roof is actually very slightly pitched meaning that rain is able to drain away.

Flat roofs and rain.

Once water is able to penetrate the roofing membrane it will soak any decking and insulation. For clarity flat roofs actually have a slight slope to allow rain water to drain off the roof but they seem flat when compared with more traditional steeply sloped roofs. Flat roofs have unique architectural characteristics that make them desirable in many situations. Together they also lead to three problem areas for a commercial building manager to monitor.

Along with the benefits of a flat roof come unique challenges. Unfortunately there is no way for water to naturally drain away from flat roofs because they are flat. There must be some momentum for the water to move into the flat roof drainage system. Flat roofs operate with the same basic principle but of course their lower angles mean that gravity isn t quite as effective in shedding water rapidly.

However over time poorer quality roofs can weaken over time. Across wide expanses of low slope roofing natural deflection in steel or wood supporting pieces within the roof deck can cause ponding. Calling this type of structure flat is a bit of a misnomer because no roof is ever really flat. The second disadvantage is the lack of roofing material options.

The slope should be a minimum of 1 in 80 but in practice a minimum slope of 1 to 40 should be used to allow for deflection of the roof and for normal building tolerances. They are ideal for climates that don t experience large quantities of rain and moisture. This causes water to stand which can cause major problems. Flat roofs do drain but not nearly as efficiently as a roof with any kind of pitch.

A more appropriate name is low slope roof. A light rain or drizzle for example remain remain on a flat roof for a short period of time. A rooftop garden or additional outside living space are the top reasons people choose flat roofs. Of course this is a con.

Flat roofs must be slightly sloped towards the middle or the edges to allow water to drain properly. Flat roofs and rain it seems go hand in hand. High winds and heavy rain can damage a flat roof or cause it to leak. Therefore water has a tendency to puddle and remain on the roof which could lead to the roofing material breaking down or to eventual leaks particularly along the seams.

But it is possible to. All roofs must be slightly sloped to allow for proper drainage.