As another annoyance, lumber shrinkage often results in subfloors and stair treads squeaking under foot traffic. This squeaking can be avoided by using adhesive to provide a tight bond between components and prevent adjacent surfaces from rubbing together. These individual conditions usually require the assessment of an acoustical engineer. United States Gypsum Company assumes no responsibility for the prevention, cause or repair of these job-related noises. In wood-frame construction, one of the most expensive problems encountered is fastener pops, often caused by lumber shrinkage, in drywall surfaces.
Shrinkage occurs as lumber dries.
Gypsum surfaces can also crack, buckle or develop joint deformations when attached across the wide dimension of large wood framing members such as joists. Shrinkage tends to be most pronounced away from outside edges and toward the center of the member. When nails are driven toward the central axis, shrinkage leaves a space between the board and the nailing surface, as shown in the drawing below. Using the shortest nail possible with adequate holding power will result in less popping due to shrinkage. Longer nails, however, usually are required for fire rated construction, as specified by the experiments.