Wet Insulation

Old 01-02-08, 06:44 PM
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Wet Insulation

I have a 9 year old two-story colonial in Maryland. Last winter, while doing some remodeling, I discovered that the insulation on the upstairs around the entire perimiter of the house was wet. It was completely soaked on the north side and more than damp on the other three sides. I cut holes in the drywall on each side and felt the insulation once I realized how bad the north side was. The construction was, from the outside in: vinyl siding, Energy Brace sheathing, fiberglass insulation (R13), kraft paper, drywall. I have a whole house humidifier and keep the humidity between 45-50% during the winter. The builder and a third party contractor believed that the water source was rain/melting snow getting behind the siding and wicking through the seams of the Energy Brace (which were supposed to be taped, but never were). I had all the siding removed, the seams were taped and the house was Tyvek wrapped and then re-sided using new siding. So now the construction is, from the outside: vinyl siding, Tyvek, Energy Brace with taped seams, R13 fiberglass insulation, kraft paper, drywall. We were in the middle of a long dry spell in the summer and the insulation dried out. Now that it is winter, I have the humidifier running again, and we just had a lot of hard rain. I just checked the insulation and it is again as wet as it was last winter. I don't believe it is humidity/condensation, since the humidity level is really not that high. There is absolutely no evidence of water in the attic, so I don't think rain is leaking in from the roof and running down. I don't think I have any external pipes, and definitely don't have them on all four walls. The water is found both near and far away from windows, so I don't think it is a window leak issue. At this point I am completely stumped and looking for any ideas. Can anyone think of anything that might be causing this?
Old 01-02-08, 07:34 PM
Join Date: Mar 2005
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Wet Insulation

Your fiberglass insulation will not dry out when it is in place. The water you are seeing could be from last year or who knows when. You may have thought the insulation was dry after the summer, but you cannot tell by looks or feel.

Fiberglass does not absorb water, but it will hold enough moisture to cause a ceiling to come it over time. Obviously, your wet insualtion is doing little since 1/2 to 1% moisture can cut the insulation value by as much as 50%.

Did the same contractor install the new house wrap and siding? that could be part of the problem since the same practices were followed. Are the contractors window installers certified or are they just carpenters?


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