Where the rafter spacing is 24 inches on center or less roof boards may be used that have a minimum thickness of 5 8 inch for solid sheathing and 3 4 inch for spaced sheathing.
Minimum roof pitch wisconsin.
The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.
Where the rafter spacing is greater than 24 inches on center roof boards shall be tongue and groove at least 1 5 inches thick.
I e 4 inches of rise per 12 inches one foot of run.
However you can only use this pitch with built up roofing or specialized.
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.
Minimum roof pitch for shingles.
Note that roof pitch is sometimes used in parallel with roof slope.
Anything above that will require you to put out higher cost because they are already considered as higher pitch.
With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 20 0 for slate roofs.
The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot.
The standard of lower pitch actually ranges between 1 12 to 5 12.
Sps 321 27 2 2 lateral restraint of walls.
However roof pitch is technically measured and defined differently and will not be discussed here.
Provisions shall be taken to absorb the horizontal thrust produced by a sloping roof through the use of wall ties ceiling joists beams at the ridge or at the wall or a system designed through structural analysis.
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.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
Use our wisconsin roof snow loads map to easily determine the roof design snow load wisconsin administrative code.
The values given here.
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.
A roof pitch of 7 in 12 is equal to 30.
A pvc roof is a lot more durable and longer lasting that a conventional epdm rubber roofing system.
Sps 321 27 note note.
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.
Wisconsin has not adopted the international residential code irc and utilizes its own uniform dwelling code udc for all residential structures.
Sps 321 subchapter 2 for any location in the state of wisconsin.
