Minimum Slope Of Pitched Roof

It is uncommon to find a roof below 15 but for those very low pitch applications there are interlocking clay pantiles available suitable for use down to 12 5.

Minimum slope of pitched roof.

If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12. The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot. However roof pitch is technically measured and defined differently. I e 4 inches of rise per 12 inches one foot of run.

The standard of lower pitch actually ranges between 1 12 to 5 12. Roof pitch is the measurement of roof steepness. The way pitch also known as roof slope is measured is rise over run. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.

Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. The minimum roof pitch for shedding snow is around 30 or a 6 12 or 7 12 slope although this is not a definite as the material of your roof the direction of the snow and wind are some factors that can affect whether or not snow will slide as roofs of as little as 10 have been reported to shed snow. Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials. Asphalt shingles can only be installed on roof slopes of 2 12 or greater.

However you can only use this pitch with built up roofing or specialized synthetic roofing. The metal roof minimum slope doesn t stray far from other building with different material. This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels.

So if your roof rises 4 inches for every 12 inches of horizontal length then the pitch of your roof is expressed as 4 12. Asphalt shingles minimum roof slope roof pitch r905 2 2. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. Traditionally a minimum roof pitch of 20 was recommended in bs 5534 but modern tiles and slates have now been designed for applications as low as 15.

The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. The minimum roof slope for metal roofs is dependent upon the roof profile. Note that roof pitch is sometimes used in parallel with roof slope.