Roof assemblies and rooftop structures 780 cmr 1501 0 general 1501 1 scope.
Roof pitch for massachusetts.
The massachusetts state building code 364 780 cmr seventh edition 8 22 08 effective 9 1 08 1503 2 flas hing.
Panels joined with an applied lap sealant can go as low as 12.
The minimum roof pitch is also subject to the standards set forth by the various building codes used in the respective regions.
Roof pitch refers to the slope which the rafter creates.
The chief reason for having a roof pitch is to redirect water and snow away from the roof and avoid any percolation that might result from stagnation of water on the roof.
A reversed gambrel or mansard roof with the lower portion at a lower pitch than the upper portion.
The minimum pitch for metal roof shingles and lapped non soldered panels is 3 12.
Importance of a roof pitch.
Pitch is typically expressed as a ratio of the number of rising units to the number of 12 horizontal units since there are 12 inches to a foot.
So a roof that rises 3 inches for every 12 inches has a 3 12 pitch.
In massachusetts minimum roof pitch must take into account the roofing material and is defined by the state department of public safety.
After that the miimum pitch for metal panels depending on the methods used to join the panels.
Often you express roof pitch as the ratio between the rise and the run in the form of x 12.
A raised structure running part or all of the way along the ridge of a double pitched roof with its own roof running parallel with the main roof butterfly roof v roof london roof.
On roofs with a pitch lower than 4 12 but greater than 2 12 this requirement changes and the roof must entirely be covered with ice water shield before asphalt shingles can be applied.
The below diagram helps outline exactly how to determine how much ice water shield is needed on any given roof above 4 12 pitch.
A roof with a monitor.
All pricing information on this page is based on average industry costs and is subject to variance for project specific materials labor rates and requirements.
How roof pitch determines suitable roofing systems.
The provisions of 780 cmr 15 00 shall govern the design materials construction and.
For that reason flat roofs are limited to these types of covering materials.
If you re estimating materials for your roofing project you can use our roofing calculator to estimate the number of squares you ll need or use our roof pitch calculator to find the pitch.
Flat and nearly flat roofs a pitch of 1 in 12 or 2 in 12 cannot be covered with shingles or shakes of any material since there is not enough angle to combat the danger of blow off.