High moisture content in wall cavity
My home has alarmingly high humidity and moisture readings (70%) in the wall cavities throughout both floors. The exterior is stucco with cedar in some places, the areas that are covered in cedar are dry. I opened up one of the walls and confirmed that the air was hot and damp but there was not any leaks. Question, is this dangerous long term? Some of the holes I drilled into the walls smell musty my concern is there is condensation building up internally that could lead to mold and rot. The summers are incredibly humid in my area (it was 100 degrees today). Has anyone seen this before or know of a remediation? I really hope I don’t need to replace all my exterior stucco.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
abrown,
The difference between the areas covered in stucco and those with cedar is probably due to stucco being a reservoir cladding that holds moisture which gets driven into the walls by sunshine.
https://www.greenbuildingadvisor.com/article/when-sunshine-drives-moisture-into-walls
Whether that poses a real problem is very situation dependent. Beyond a musty smell, did you see any visible damage to the sheathing?
Hi, thank you for the reply. I don’t know what sheathing is but there is no visible degradation of any of the internal drywall or external stucco. The only reason I know of the issue is i had a separate leak in another part of the house which prompted me to buy a moisture meter at which point I tested other parts of the house and found the high moisture content in the walls.
(I googled sheathing) I opened up one of the walls and did not see any visual issues (mold rot ect) anywhere. The drywall itself felt fine but the wall cavity is fairly hot and damp.