Normal Slope For Roofs

Traditional roofing materials such as traditional clay tiles and timber shakes shingles need a relatively steep pitch in excess of 40 degrees to be waterproof.

Normal slope for roofs.

Roofs at the lower end of the range about 4 12 to 6 12 are relatively easy to walk and work on. The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. Definitions vary on when a roof is considered pitched. The way pitch also known as roof slope is measured is rise over run.

The exact roof slope in degrees is given by the arctangent. A handy roof slope estimator can help you determine if your roof slope is likely too low for shingles. 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. The majority of north american residential roofs have historically been constructed with a slope between about 4 12 and 9 12.

Roof pitch is the measurement of roof steepness. The typical roof slope follows specific materials and design techniques to ensure perfect safety from leakage. Arctan 3 12 14 0 the primary purpose of pitching a roof is to redirect water and snow. In degrees 10 2 in 12 or 1 in 6 is considered a minimum.

A common range is given from 1 12 to 4 12 whereas conventional dimensions vary from 4 12 to 9 12 but the steep roofing technique follows slope above 9 12 with additional fasteners. The final point influencing the roof slope is the preferred choice of roofing material. Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled. In general the minimum slope for a flat roof is 1 0 but as stated earlier this is only possible in theory.

Flat roofs which aren t perfectly flat require a small slope to allow for water runoff. Pitches above 9 12 are very highly angled and are designated steep slope roofs. More modern tiling and felt shingle systems can achieve lower slopes down to about 20 degrees. Low pitched roofs are generally difficult to maintain and you need special materials to prevent leaks.

Generally such roofs have a pitch ranging from 1 2 12 to 2 12. A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible. Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

Since they vary in quality as well as method of installation the choice preferred for a flat roof will ultimately have an effect on the final slope of the flat roof. 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. These roofs have a pitch less than 4 12. You can divide roofs into these categories.