Miniumum Slope For Flat Roof Climate Zone 7

The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process.

Miniumum slope for flat roof climate zone 7.

The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. One of the best ways to insulate a roof whether sloped or flat is to install rigid foam on top of the roof sheathing. According to the international building code the typical built up flat roof that uses tar or asphalt goes by the guideline that for every foot 12 inches of a flat roof a minimum of inch must step up or down. This logic does not consider that lower sloped roofs will not drain water at the same rate as roofs with greater slopes.

If these issues are addressed during the design stage and the roofing contractor does his job these systems will almost always perform as intended. Minimum metal roof slope depends on the roof profile building design climate and site location. That table calls for a minimum of r 5 foam for climate zones 1 through 3 r 10 for climate zone 4c r 15 for climate zones 4a and 4b r 20 for climate zone 5 r 25 for climate zone 6 r 30 for climate zone 7 and r 35 for. Equipment power totaling 7 watts ft.

If 75 of your roof meets the exception criteria you also don t have to comply. This is the basis for calculating the angle which is approximately a 1 19 degree slope. The minimum slope the code allows is in 12 in. It takes the manufacturer s recommendations the unique conditions of the roof as well as the skills and the expertise of the installer to arrive at the right slope.

In general the minimum slope for a flat roof is 1 0 but as stated earlier this is only possible in theory. 2 heating system capacity 17 000 btu hr 5 kw and a heating thermostat set point that is restricted to 50ºf average wall and roof u factor 0 200 in climate zones 1 5 and 0 120 in climate zones 6 8 comply with the roof solar reflectance and thermal emittance provisions for. Additionally asce 7 16 requires a minimum 1 in 12 roof slope to promote free drainage for secondary members parallel to a free drainage edge. This means that even less than the minimum of in.

The 1 in 12 is significantly more than the commonly specified 1 4 in 12 and reflects the need of an increased slope to promote free drainage. Typically large footprint single story warehouses and pre engineered metal buildings will utilize low slope metal roof systems. Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12. The key factors are usually snow loading requirements adequate slope and the use of snow guards when needed.