Ontario Roof Pitch

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.

Ontario roof pitch.

Asphalt base gravelled 1 in 50 1 1 in 4. The table below shows common roof pitches and the equivalent grade degrees and radians for each. There are some standing seam metal roofing options available from atas and other manufacturers that can be installed on a roof with pitch of 1 12. I e 4 inches of rise per 12 inches one foot of run.

Coal tar base gravelled 1 in 50 1 1 in 25. Framing any roof but particularly a gable roof low slope roof and cathedral ceilign roofs requires collar ties rafter ties and possibly a structural ridge beam to support the roof and to. Usually average roof pitch is determined using the same roof length method. Commonly it is 3 4 th of span as per gothic rafter must be equal to span.

It is often compared to slope but is not exactly the same. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. Roof framing suggestions canadian guidelines. 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.

For a gothic style the rafters must equal the span 60 while an elizabethan style requires the rafters to be longer than the span. 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. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. For instance a 7 12 roof pitch means that the roof rises 7 inches.

With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate 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 article excerpts from provides copies of roof framing suggestions from canadian building codes and the cmhc wood frame house construction guide. Glass fibre reinforced polyester roofing panels.

Asphalt base without gravel 1 in 25. You could also opt for a pvc flat roofing membrane. 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. In snowy areas your roof should be at least 10 12 40 to allow snow to shed while the safest roof pitch in very windy areas is between 4 12 6 12 18 5 26 5.