Wet Insulation - What's Normal vs. Damaged??

16 years ago

Our house has blown in cellulose insulation. We have been told that this application uses water to expand the insulation once it is in place, and that the normal moisture level for stabilized insulation of this type is around 25%. It also has borax in it which is supposed to help prevent mold and mildew.

The Problem: Our contracter did things out of order and put in the insulation and drywall before the roof was on. We had over 5" of wind driven rain and everything got wet. We brought in an independent inspector to force the contractor to remove all sheetrock. Now we are in a fight as to the appropriate level of moisture in the insulation and over what parts of the insulation need to come out and be re-installed. The contractor claims that the insulation goes in completely wet and the taping and mud application of the sheetrock will raise the moisture levels back over 30% anyways. The inspector found areas that were 99% wet behind the sheetrock, and now that it has been removed we can visibly see many areas of soaking wet insulation, and other areas where the texture of the insulation has changed appearing that it was very wet from the leaking rain at one point and has now dried.

The Question: What needs to come out and what can stay in? If the sheeting is wet behind insulation that is 30% or lower, does that insulation still need to come out? Or will the sheeting dry on it's own?

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Comments (6)

sierraeast
16 years ago
I disagree with the claim that the taping and finish coats will be around 30%,however if you have a sparayed on texture such as orange peel or a knockdown, that will bring the moisture level up significantly.

The moisture in blown in cellulose is miniscule amounts to act as a bonding agent to allow the insulation to "stick".It's not a significant amount used.I would suspect having that amount of physical water soaking into the cellulose will cause it to lose r-value similar to when fiberglass gets wet, only the cellulose can take more abuse.

I would insist that all areas that have been saturated be replaced.As far as the percentage numbers are concerned, i dont have an answer. Maybe someone else out there can crunch those statistics for you, but you dont want to cover up anything that has gotten a significant amounts of water/moisture.

You will want to be patient and let all other areas dry including the framing members and check them for warping, twisting, bowing, cracking, etc. before re-covering.If you are in a high humidity area, this might take awhile and the services of a moisture reading that you suggested in your previous post would be a great idea.
sue36
16 years ago
Any cellulose insulation that got wet from the rain must be removed. The R value has been greatly reduced by the water.

Do you know who the supplier of the cellulose was? I would contact them for their specs. Was this inspector an insulation specialist?

My understanding (which is limited and based on the research I did when we looked into insulations) is that there is a difference in the type of moisture in the insulation when it is applied than if it gets wet later. It is not the level of moisture so much (that will come down once it dries), it is that it ever got wet post-install that matters. Any insulation that got wet post-install is basically ruined now. The moisture meter only tells part of the story.
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charliedawg
16 years ago
I don't know anything about insulation. Just wanted to say that I would have little faith in your builder and his knowledge of anything because he installed drywall without a roof. I think your 110% right to search elsewhere for the answers that you need.
too_picky
Original Author
16 years ago
I did addtional online research today and confirmed that any damaged insulation needs to be removed even if it is "dry" now. The outside water introduces different mold spores into the insulation that can be resistant to the borax that is in there. This means that it very likely can grow mold and once it gets started the mold will thrive in the old newspaper material that makes up blown in cellulose. I also learned that you shouldn't hang dry wall until the insulation has dried out to below 25% moisture content and that the final moisture level should be below 15% once it is all said and done. I just went by the house at lunch and thankfully the insulation was all marked for removal by the project manager and the roof was almost finished. Now I just have to make sure that the insulation isn't "recycled" by the contractor and put right back up again.

My faith in the builder is totally shot. Right now I don't trust him as far as I can throw him. He's lied, manipulated, and delayed the project in more ways than I can count. The next question is do we fire his @** or hang in there and watch him like a hawk, sweating everything until it is finished? The region we are in does not have many contractors to choose from and at this stage of the project my involvement level would likely be the same if we switched to a different contractor or if we stayed. Either way it's going to be more work, more money, and more stress. Sigh, why do people build houses anyways! =)
cbtexas
16 years ago
When you go to give the check for your next draw, go to the restroom and run the check under water saturating it. When the ink starts to run from the moisture himm and haww around before you write him another one. Your GC sounds like a doozy.
sniffdog
16 years ago
i didn't realize it was that much rain. As Mike Holmes would say "take it all down" . You have to get the cellulose out so the wood in the cavities can dry out.

Make them take it out - fight that fight now. Then make the builder do it right - get roof shingles and flashing on first and then start the insulation and drywall process over aftre the house has proven to be weather tight - just like he should have the first time. This is inexcusable.

Wet Insulation - What's Normal vs. Damaged??

Comments (6)

sierraeast

sue36

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Wet Insulation - What's Normal vs. Damaged??

Comments (6)

sierraeast

sue36

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