Roof and wall penetrations must be treated how to prevent entry of water, rodents, and insects?

Roof and wall penetrations play a crucial role in maintaining the integrity of a building's envelope, which protects against the elements. To effectively prevent the entry of water, rodents, and insects, these penetrations must be flashed and sealed.

Flashing is a material or system that directs water away from areas of potential leaks, such as around vents, chimneys, and gutters. Proper flashing ensures that water cannot accumulate at these transition points, significantly reducing the risk of leaks and resulting water damage.

Sealing, on the other hand, involves using caulk or other sealing materials to cover gaps and joints where penetration occurs. This step is essential for creating a barrier that not only prevents water but also keeps out pests. Insects and rodents are highly skilled at exploiting small openings, and sealing these gaps effectively safeguards the interior from infestations.

Together, flashing and sealing work to create a reliable defense against moisture intrusion and unwanted critters, which is why this approach is the standard best practice in construction and maintenance within the North Carolina Mechanical Code. Other methods listed, such as painting or treating materials, do not provide the necessary barrier against water and pests, and while insulation may be important for temperature control, it does not address the specific issue of penetration protection.