Which of these does the NRCA recommend for step flashing in a wood shingle roofing system?

The recommendation for step flashing in a wood shingle roofing system being exposure plus 3 inches in length by 8 inches wide for non-standard shingles aligns with the best practices outlined by the National Roofing Contractors Association (NRCA).

The dimensions specified ensure that the flashing adequately overlaps the shingles and provides a reliable barrier against water infiltration. Step flashing must be precisely calibrated to conform to the exposure of the shingles, and the additional 3 inches in length aids in directing water down the roof and away from the wall, reducing the potential for moisture issues. The width of 8 inches ensures sufficient coverage and adds to the overall durability and effectiveness of the flashing.

Adhering to these dimensions is critical in achieving proper installation and maintaining the integrity of the roofing system, thus preventing leaks and prolonging the roof's lifespan. This guidance is particularly relevant when dealing with non-standard shingles, which may have variations in exposure and installation methods compared to standard shingles.