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When it rains hard, we get the second rain inside in the form of condensation on the underside of the roof dripping down on us. We have a standard corrugated type roof and no interior ceilings (our older house at present is one big shell - like a barn). Any builders out there know how to prevent this accumulation of condensation? Someone suggested that if we put in ceilings that will prevent it. But common sense tells me the ceilings will just get soggy over time. If there are vents that would work and not bring water inside during downpours I would try that. I'd like to know what the standard building technique is for this problem. Thanks for any suggestions.
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I think that the ceiling idea will solve the problem. You will not be getting all that condesation from the ambient air building up on the underside of the roof. Also, with a ceiling you would need the vents that normaly come when homes are built with ceilings. I'm not a builder or anything like that just MHO. It would be a good thing to check with a pro.
Leif
I just love Aloha and Hawai'i
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Maud,
The "second rain" is from warm, humid interior air condensing on the underside of the roofing which has been cooled down below the dew point by the rain.
There are a couple of options;
The best,IMO,is the most expensive. Remove the roofing, apply plywood and felt roofing paper and re-install the roofing.
The next possibility, and I am not sure if it is available on BI, is to have sprayed foam insulation installed on the underside of the roof. This would probably be the cheapest of the best solutions.
Next option is to install rigid insulation on the underside of the roof. I would not recommend this though, as it will not absolutely prevent interior air from coming in contact with the colder roofing.
I think that even with a ceiling and ventilation, there will still be a "second rain" in the attic, a potential moisture and mold issue.
First thing to try is probably to use a dehumidifier with all the windows closed. Lower relative humidity on the interior will lower the dew point, perhaps enough to stop the condensation. Higher electricity costs though.
good luck, Dan
