When installing 1 x 6s, how many courses of shingles should be nailed to each board?

When installing 1x6 boards as part of a roofing system, the standard practice involves nailing two courses of shingles to each board. This approach is primarily due to the need for adequate coverage and weatherproofing of the roof.

Having two courses allows for overlapping the shingles effectively, which helps to prevent water infiltration. Each course provides additional protection against wind and rain, ensuring that the roof not only looks aesthetically pleasing but also functions properly to shield the structure beneath it. This method also helps to maintain the integrity of the installation by allowing the shingles to conform to the 1x6 boards, thereby preventing any gaps that might lead to leaks.

The reasoning behind using two courses lies in the balance between effective coverage and structural integrity, making it the best practice for roofing installations using 1x6 boards. Thus, this answer aligns with the principles of roofing installation and is considered the industry standard.