What might be a sign of trapped moisture in roofing?

The presence of blisters on the roof is a clear indication of trapped moisture. This moisture can become trapped beneath the roofing material, typically as a result of poor ventilation, leaks, or insufficiently dried roofing materials. As the moisture heats up from the sun, it converts to vapor and causes the roofing membrane to bubble or blister. These blisters can compromise the integrity of the roofing system by creating weak spots that may eventually lead to leaks and further deterioration if not addressed promptly.

While the other elements might be relevant to broader roofing or building issues, such as insulation value affecting energy efficiency or electrical outages stemming from wiring problems or water damage, none directly relate to the immediate physical manifestation of moisture accumulation beneath roofing surfaces. Therefore, the formation of blisters stands out as a specific and noticeable sign of trapped moisture in roofing.