North Carolina Home Inspector Practice Exam

Is it acceptable to mount an A/C unit on pressure treated 4x4's on a built-up roof?

1. No, it poses a structural risk

2. Yes, no problem

3. Yes, but with restrictions

4. No, due to moisture concerns

The correct answer is: Yes, no problem

The appropriate answer reflects a situation where mounting an A/C unit on pressure treated 4x4's on a built-up roof is considered acceptable. This combination is often used because pressure treated wood is designed to resist moisture and decay, making it suitable for outdoor applications. Built-up roofs, which are typically composed of multiple layers of roofing material, can generally support additional structures like A/C units when installed properly. However, while the framing material itself might be suitable, considerations should be made for the overall load on the roof, the design requirements from local building codes, and the necessary precautions for drainage and anchoring of the unit. The use of pressure treated wood can mitigate concerns regarding moisture, as it is less likely to rot when exposed to the elements compared to untreated wood. Mounting an A/C unit on a sturdy, treated wood framework can provide a secure base while minimizing risks related to structural failure, provided that installation is executed correctly. Understanding these details is essential for ensuring that such installs are safe and comply with regulations.