NASCLA Accredited Commercial General ContractorThermal and Moisture ProtectionMedium
During a roof inspection of a commercial building, a contractor observes a significant amount of entrapped moisture within a fully adhered single-ply roof system, indicated by soft spots and blisters. The most effective long-term solution to address this issue is to:
- AInject a drying agent into the affected areas.
- BInstall roof vents to allow the moisture to escape.
- CLocate all wet insulation, remove it, repair the membrane, and replace with dry insulation.
- DApply a liquid-applied coating over the entire roof surface.
Show answer & explanationAnswer & explanation
Correct answer: C. Locate all wet insulation, remove it, repair the membrane, and replace with dry insulation.
Entrapped moisture in a fully adhered system often means the insulation is wet, which compromises its thermal performance and can lead to deck deterioration. The only reliable long-term solution is to remove the source of the problem—the wet insulation—and repair the membrane to prevent future ingress.
Why the other options are wrong
- A. Injecting a drying agent is typically a temporary or partial solution and may not fully address saturated insulation or the original source of moisture.
- B. Roof vents may help with minor, surface-level moisture, but are often insufficient for significant entrapped moisture within a fully adhered system.
- D. A liquid-applied coating might temporarily seal minor leaks but will not remove existing entrapped moisture or restore the insulation's R-value.
Entrapped Roof Moisture Remediation
Entrapped moisture in roof assemblies requires identifying the source, removing saturated materials, and repairing the roof system to prevent recurrence.
- Moisture compromises insulation's thermal performance.
- Leads to deck deterioration and potential structural issues.
- Requires invasive repair for effective long-term solution.
Memory trick: Moisture's Out: Find, Remove, Repair, Restore.