I have a temp/humidity sensor in the attic. The attic and outside temperatures vary, but the DEW POINT should be the same.
Often, they are. But it's been wet this month and they don't always track. At 2PM, the outside was 41F 41% DP=19 In the attic, it was 47F 90% DP=44 That seems to be a problem.
But at 5PM, it's outside 36F 44% DP=16 Attic is 46F 76% DP=39
Other times the inside/attic dew points are about the same.
I've been using this site:
I don't have a historical log, but I haven't been alarmed in the past.
House is 47 years old ranch in Portland, Oregon. Two layers of asphalt shingles. Wasn't leaking when I put on the second layer.
The insulation is fiberglass. I expect it holds some moisture and there will be some delay in the humidity dropping as the outside humidity changes.
I called the roofer and asked about humidity in the attic and was told to email the data. The response basically ignored what I wrote and gave no answer.
There's a lot of insulation in the attic and I can only get at about half of it without messing up the insulation. I see no evidence of leakage around all the stuff sticking thru the roof and no evidence of water damage, but I can't see much of the wood on the inside of the roof.
Am I worrying too much? Or should I put on the rubber boots and trudge thru the insulation to get a better look.
What humidity should I expect to see in the attic?