Standard Roof Pitch In Michigan

Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled.

Standard roof pitch in michigan.

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. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Asphalt shingles continue to be the most widely installed roof covering option in north america. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

Minimum roof pitch for shingles. Rise multiplier rise multiplier 1 to 12 1 01 6 to 12 1 12 2 to 12 1 01 8 to 12 1 20 3 to 12 1 03 12 to 12 1 42 4 to 12 1 06 15 to 12 1 60 5 to 12 1 08 18 to 12 1 80. Pitches above 9 12 are very highly angled and are designated steep 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.

Usually average roof pitch is determined using the same roof length method. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal 17 percent slope or greater. Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs.

They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. However you can only use this pitch with built up roofing or specialized synthetic roofing. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. Overflow drains having the same size as the roof drains shall be installed with the inlet flow line located 2 inches 51 mm above the low point of the roof or overflow scuppers having three times the size of the roof drains and having a minimum opening height of 4 inches 102 mm shall be installed in the adjacent parapet walls with the inlet flow located 2 inches 51 mm above the low point of the roof served.

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.