What is the main problem if a wood shingle is nailed too high?

What is the main problem if a wood shingle is nailed too high?

• A. It will curl
• B. It will crack
• C. It will delaminate
• D. It will warp

Answer: (A)

When a wood shingle is nailed too high, the fastener holds the shingle at the upper part rather than giving a solid seat across a larger portion of the shingle. Because wood moves with moisture and temperature, the restrained top and the free lower portion allow the bottom edge to lift and curve as it dries and expands. That upward curl is the most immediate and common problem, since it prevents the shingle from lying flat against the layer above and creates gaps that can let water seep in and reduce wind resistance. The other issues—cracking, delamination, or warping—can occur for different causes, but curling directly results from fastening too high and not keeping the shingle properly seated along its lower edge.

When a wood shingle is nailed too high, the fastener holds the shingle at the upper part rather than giving a solid seat across a larger portion of the shingle. Because wood moves with moisture and temperature, the restrained top and the free lower portion allow the bottom edge to lift and curve as it dries and expands. That upward curl is the most immediate and common problem, since it prevents the shingle from lying flat against the layer above and creates gaps that can let water seep in and reduce wind resistance. The other issues—cracking, delamination, or warping—can occur for different causes, but curling directly results from fastening too high and not keeping the shingle properly seated along its lower edge.