California Residential Inspector Practice Exam

What is the requirement for holes drilled in preservative-treated wood?

1. They must be filled with concrete

2. They must be treated on site in accordance with AWPA M4

3. They must be sealed with wax

4. They may be left untreated

The correct answer is: They must be treated on site in accordance with AWPA M4

When holes are drilled in preservative-treated wood, it is critical to ensure that the wood maintains its resistance to decay and insects. The requirement to treat the exposed surfaces of the wood in accordance with AWPA M4 (American Wood-Preservers' Association Standard M4) provides guidance on how to properly protect the integrity of the wood post-drilling. AWPA M4 outlines the specific methods and types of preservatives that should be applied to prevent deterioration and maintain the protective benefits of the treatment. Treating the drilled holes on site ensures that any cut surfaces are adequately protected from moisture or pests that could exploit these exposure points. This is particularly important as untreated holes can become entry points for moisture and insects, diminishing the lifespan and integrity of the wood. Other options do not address the necessary protective measures. For example, filling the holes with concrete or sealing them with wax may not provide the appropriate level of protection and might not comply with the specific guidelines established for preservative-treated wood. Leaving the holes untreated compromises the effectiveness of the wood treatment, leading to potential vulnerabilities. Adjusting the treatment in accordance with AWPA M4 is the most reliable way to maintain the wood's resistance properties.