CSLB Class B General Contractor's License Practice Exam

When you have a gap in the building envelope, what do you do to prevent air leakage?

1. Stuff insulation into gaps

2. Put caulking in and around the gaps

3. Weather seal, weather strip, and apply caulking

4. Nothing, all buildings require air leakage

The correct answer is: Weather seal, weather strip, and apply caulking

To effectively prevent air leakage through gaps in the building envelope, utilizing a combination of sealing techniques is essential. The chosen method of applying weather seal, weather stripping, and caulking creates a comprehensive barrier that addresses various types of gaps and cracks that may exist. Weather seals and strippings are designed specifically to fit around movable components such as doors and windows, where air might easily escape or enter. These materials compress and expand, ensuring a tight fit that can adapt to changes in temperature and movement. Caulking, on the other hand, is effective for sealing stationary gaps in materials such as wood, metal, or masonry, providing a watertight and airtight finish. This multi-faceted approach is superior because it not only blocks air infiltration but also contributes to energy efficiency, comfort, and humidity control within the building. Relying on just one method, such as stuffing insulation or only using caulking, may not provide the same level of effectiveness against air leakage. Therefore, integrating various sealing methods ensures a more robust and reliable solution for maintaining the integrity of the building envelope.