Flat Roofs And Rain

Together they also lead to three problem areas for a commercial building manager to monitor.

Flat roofs and rain.

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. While not frequent per se the low slope of a flat roof does make it more prone to certain problems particularly when it interacts with the elements. 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 it seems go hand in hand.

Along with the benefits of a flat roof come unique challenges. A more appropriate name is low slope roof. Unfortunately there is no way for water to naturally drain away from flat roofs because they are flat. They are ideal for climates that don t experience large quantities of rain and moisture.

Flat roofs do drain but not nearly as efficiently as a roof with any kind of pitch. 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. Flat roofs have unique architectural characteristics that make them desirable in many situations. High winds and heavy rain can damage a flat roof or cause it to leak.

All roofs must be slightly sloped to allow for proper drainage. 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. This causes water to stand which can cause major problems. Once water is able to penetrate the roofing membrane it will soak any decking and insulation.

A light rain or drizzle for example remain remain on a flat roof for a short period of time. Excessive rain heavy snow and built up ice all pose extra challenges for flat roofed homes. Of course this is a con. There must be some momentum for the water to move into the flat roof drainage system.

Flat roofs must be slightly sloped towards the middle or the edges to allow water to drain properly. But it is possible to. A rooftop garden or additional outside living space are the top reasons people choose flat roofs. 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. Across wide expanses of low slope roofing natural deflection in steel or wood supporting pieces within the roof deck can cause ponding.