Ontario Roof Pitch

Usually average roof pitch is determined using the same roof length method.

Ontario roof pitch.

Modified bituminous membranes. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. 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. Coal tar base gravelled 1 in 50 1 1 in 25.

This article excerpts from provides copies of roof framing suggestions from canadian building codes and the cmhc wood frame house construction guide. 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. For a gothic style the rafters must equal the span 60 while an elizabethan style requires the rafters to be longer than the span. Asphalt base gravelled 1 in 50 1 1 in 4.

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. It is often compared to slope but is not exactly the same. The table below shows common roof pitches and the equivalent grade degrees and radians for each. So you would need to pick the right option as most regular standing seam metal roofs will require a roof pitch of 2 12 or even 3 12 at a minimum.

I e 4 inches of rise per 12 inches one foot of run. 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. Commonly it is 3 4 th of span as per gothic rafter must be equal to span. You could also opt for a pvc flat roofing membrane.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Glass fibre reinforced polyester roofing panels. 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. 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.

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. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches. For instance a 7 12 roof pitch means that the roof rises 7 inches. Roof framing suggestions canadian guidelines.