According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.
Minimum roof slope for snow load.
If you live in the us our snow load calculator compares the total weight on your roof with the permissible load calculated according to the standards issued by the american society of civil engineers regarding the minimum design loads for buildings and other structures asce7 16.
In case a slope greater than this is necessary then a double underlayment application must be used as per the requirements of the international building code.
A steep slope roof is one whose slope is greater than 3 12.
If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow.
The sloped roof snow load is calculated using equation 7 4 1.
When the roof slope is greater than 5 the roof is considered sloped.
When it comes to residential construction your roof is a visible part of the structure.
To figure out the load on your roof take the depth of snow in feet and multiply it by the weight of a cubic foot of snow.
A minimum pitch of 3 in 12 or even 4 in 12 will normally be required.
If the snow weighs 10 pounds per cubic foot and there are 1 5 feet on the roof each square foot of the roof is getting 15 pounds of pressure.
B sloped roof snow loads ps.
Roof design snow loads derived from figure 321 02 of the wisconsin.
You multiply it by whatever equation 7 1 gives you.
In general determining the pitch of an existing roof is a simple calculation.
Values of c s for warm roofs and cold roofs are as.
Sloped roof snow loads are assumed to be acting on the horizontal projection of the surface.
Btw i think there is some confusion on what i m saying about the 7 factor.
So you do not multiply cs by the minimum pf for sloped roofs.
You can click on the map below to find the minimum roof design snow load for that location.
P s cspf equation 68 5 3.
The slope roof snow load p s shall be obtained by multiplying the flat roof snow load pf by the roof slope factor cs.
All commercial buildings and structures should use the ground snow load values from the 2009 ibc and not the residential design values given below.
All snow loads acting on a sloping surface shall be considered to act on the horizontal projection of that surface.
P s c s p f.
Pitched roofs begin with with slopes greater than 3 in 12.
Suitable materials for pitched roofs.
This can be accomplished by measuring the number of inches the roof rises vertically for every 12 inches it extends horizontally.
Okay i just got the word from a highly placed source that the minimum snow load provision only applies to low slope roofs.
Minimum pitch for corrugated metal roof.
