Flat Roof Pitch Design

Roof pitch in layman s language simply refers to the steepness of the roof.

Flat roof pitch design.

Underneath the basics flat roofs are usually constructed with a ceiling nailed to joists which support a deck usually wood in residential construction a vapor barrier insulation and a roof board. Some local codes take it a step further allowing a slope of only of an inch per foot. Flat roof slope the slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches. In fact many residences have sections of flat roof on porches balconies garages and room extensions which appear so attractive.

On larger roofs it s probably cheaper to use tapered foam insulation on top of the roof sheathing. In order to ensure a finished surface with zero fall a design fall of 1 80 should be used and a detailed structural analysis should account for construction tolerances settlement and for. Flat roof design guide. It should come as no wonder then that these are experiencing a serious comeback right now.

Some bauder waterproofing systems are bba approved for use with zero falls but back falls are not acceptable and should be corrected. From there the flat roof system you choose will determine the materials you apply. According to the international code council the minimum slope for water runoff is inch per 12 inches. A common choice for flat roofing material is epdm rubber as it is highly durable waterproof and can be made from recycled materials.

This modest slope can be achieved in a number of ways. Flat roofs are built with a slight pitch of at least 1 8 per foot so water can drain either to centralized drains scuppers or a gutter system. Flat roofs are typically designed with a pitch of 10 degrees or less. Ask any architect and they ll tell you that hardly any other type of architecture is as timeless and modern as that of flat roof houses.

A completely flat roof is a poor design as water and snow will collect on it eventually leading to your roof collapsing in from the weight of it all. The pitch of a roof is arrived at by dividing the vertical rise and its horizontal span or what people in the roofing industry would refer to as the slope. The smallest pitch of a roof is 0 5 12. Flat and low sloped roofs look striking on a wide variety of architectural models especially on contemporary house designs.

This means that the rise of the slope goes up or down 8 inches for every 12 inches. There are different kinds of roofs and all these have particular specifications for their installation.