Standard House Roof Pitch

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.

Standard house roof pitch.

Minimum roof pitch for shingles. Pitches above 9 12 are very highly angled and are designated steep slope roofs. Today s standard ceiling height is nine feet. Commonly it is 3 4 th of span as per gothic rafter must be equal to span.

Newer houses are often built with nine foot ceilings on the first floor and sometimes eight foot ceilings on the second story. The table below shows common roof pitches and the equivalent grade degrees and radians for each. But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof. Gable and other multi pitched roofs allow for lower primary structures with a corresponding reduction in framing and sheathing materials.

The most commonly used roof pitches fall in a range between 4 12 and 9 12. The amount of vertical climb has for every twelve inches of lateral dimension by which roof pitches are represented. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof. Buffalo new york and montreal quebec canada specify 6 in 12 a pitch of approximately 26 6 degrees.

Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. Greek says one must keep rafter length in range of 1 9 to 1 7 th of span but as per roman style the standard dimensions are kept about 1 3 to 2 9 th of span with an angle of 23 to 24 degree. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Citation needed carpenters frame rafters on an angle to pitch a roof.

Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled. The terms are scientific in nature. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs.