What slope measurement must be achieved to use wood shingles properly?

To properly use wood shingles on a roof, the slope measurement should be 3:12 or greater. This means that for every 12 horizontal units, the roof must rise at least 3 vertical units. This slope is essential for the effective drainage of water, preventing moisture accumulation which can lead to mold, rot, and other damage to the shingles and underlying structures.

Wood shingles are designed to shed water effectively, and a slope of 3:12 ensures that water runs off quickly and does not stay on the shingles, which could compromise their integrity and lifespan. A roof with too low a slope may not provide adequate drainage, increasing the risk of water-related issues.

The other slope measurements, while they might allow for some level of general roofing installations, do not meet the specific requirements for wood shingles, as the less steep slopes sometimes lead to inadequate water runoff and increased susceptibility to leaks and deterioration of the roofing material.