For metal panel roof systems with nonsoldered seams with applied lap sealant ibc 2018 prescribes a 1 2 12 minimum roof slope.
Minimum roof slope foam.
In 12 0 25 in 12 1 19 built up roof coal tar pitch.
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.
The standard of lower pitch actually ranges between 1 12 to 5 12.
Minimum required roof slope for roofing materials.
For standing seam metal roof panel systems a 1 4 12 minimum roof slope is prescribed.
Built up roofs shall have a design slope of not less than one fourth unit vertical in 12 units horizontal 2 percent slope for drainage except for coal tar built up roofs that shall have a design slope of not less than one eighth unit vertical in 12 units horizontal 1 percent slope.
This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof systems in new construction.
9 46 built up roof asphalt.
Sprayed polyurethane foam roofs must have a design roof slope of 1 4 12 or greater 2 slope.
Minimum required slope x in 12 minimum required slope degrees asphalt shingles.
The metal roof minimum slope doesn t stray far from other building with different material.
The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot.
This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit.