Problem: Nail pops.
Cause: Wet framing lumber.
As framing lumber dries, shrinkage occurs. As the studs dry and shrink relative to the fasteners, the studs pull away from the drywall. A 10% change in moisture content can cause a spruce or fir stud to shrink up to 1/4 inch (6mm). Any subsequent movement of the board will cause the fastener to "pop" as shown in Figure 57.
Poor framing practices
Figure 57 - Nail Pops (exaggerated) - Shrinkage up to 1/4 inch
Figure 57b - Moisture content meter
- Use framing lumber with the lowest possible moisture content, maximum 14% moisture content where possible. Avoid lumber that is grade-stamped green. As an example choose "S-DRY" over "S-GRN", or where economically viable use kiln-dried lumber.
- Do not guess at the moisture content of the lumber. There are many lumber moisture meters (Figure 57b) available that will give you the actual moisture content of the lumber you are working with.
- Protect framing lumber from the elements such as rain, snow and direct sunlight.
- Inspect the framing before applying the drywall (gypsum board). Alignment should not vary by more than a 1/4" (6mm). Straighten warped studs by saw cutting and wedging as shown in Figure 58.