Insulation smell

[Stan in Oly, WA]

I added a lot of insulation to my house about 6 months ago. In the crawlspace I had batts of R-30 fiberglass installed in the joists. When that was done I had the vapor barrier replaced.

For the first few weeks after the insulation was installed, the urine-like smell that it gave off was almost overpowering. I closed up a few places I found where air from the crawlspace might enter the house, and the odor finally seemed to go away. About a month ago we started to notice that there was often a very strong urine smell in the bathroom. A good cleaning and being very careful didn't help. Then I noticed that running the exhaust fan actually made the room smell worse, and it finally dawned on me that it was the fiberglass smell.

I can seal off the bathroom better to prevent pulling in air from the crawlspace, but what I really want to know is how long the fiberglass is going to give off that smell. The air in the crawlspace is stagnant. There is no cross ventilation. Also, the weather has been unseasonably cool and damp---we've had almost no summer-like weather yet this year. Will it take circulation of warm, dry air to get rid of the smell, or is there something else I can do?

Thanks, Stan

 

[rhouston]

I don't know where you get your fiberglass insulation but I have NEVER noticed any odor associated with Fiberglass insulation. Is it possible that yours had a visitor before you bought it?

 

[Anonymous-0]

Strange. The vapor barrior go's between living space and the insulation. In a crawl space it's above the insulation. Plastic might be lying on the ground but not sealed under the insulation.

 

[Anonymous-0]

I would look to see if you don't have a flue that has come loose or maybe seal your joints. The smell would have to be penetrating two layers of flooring which would be unlikely or else coming up through a flue if your ductwork is in the crawlspace or the crawlspace access.

 

[Anonymous-0]

I can recall an odor from pink owens corning insulation, not too distant from a urine smell, not the same, but a sour kind of odor, always when new material arrived for stock in the warehouse, I used to unload the shrink wrapped bundles, but assumed this to be a smell associated with recently manufactured materials, similar to formaldehyde in aspenite and other composite type sheet goods, goes away after awhile.

I'd contact the manufacturer and see if it's something they recognize, I do remember new materials having a noticable odor, nothing overbearing but enoughto notice, definitely not a urine odor, but sour, you may want to investigate for rodents if it's a urine smell.

 

[IH2444]

Give your crawl space some ventillation.
Is your ducts in the crawlspace ? They might need sealing too.

 

[Goose]

I'd get some ventilation in that crawl space. When we built our present house, we just put a 4 foot crawl space under it because of a high water table.

We have seven 8"X16" vents around the perimeter of the house, and I rigged an old furnace squirrel cage blower in one end. In damp weather, if you turn the blower on and walk outside to the opposite end of the house 70 feet away, you can smell musty air coming out of the vents.

 

[Anonymous-0]

Do you have a piece of the insulation left over? See if getting it damp produces the same strong urine odor. You may have a humidity problem in the crawl space due to a lack of circulation.

 

[Anonymous-0]

I,m not saying this is the cause but, a couple years ago in the fall when it became heating season when we showered and ran the bathroom exhaust fan we detected a urine smell. Then it showed up when we had driving west winds against the west facing bathroom wall. One day I commented that it smelled a little like mouse p@@ and my wife thoguht she heard something. come to find out, a mouse was in one stud cavity from the out side. It never got in the house. I ended up pulling off siding and cleaning out an eventually replace urine soaked drywall. Perhaps sealing up and insulating is allowing pulling odor from elsewhere.

 

[Anonymous-0]

Stan, is your vapor barrier between the floor and the insulation? I think it's supposed to be on the "living space" side of the insulation, although I remember reading that in areas of high humidity it may need to be on the "outside" of the insulation. You may have a lot more humidity in Washington State than we do here in Illinois.

I'm planning to insulate the floors in my old house. What did you use to support the insulation at the bottom of the floor joists? I was planning to seal the bottom with OSB. We occasionally get "critters" under our old farm house, and I feel like I need something to prevent the insulation from getting torn up. I've seen folks use chicken wire, and also electric fence wire laced between nails on alternating joists.

Heating/cooling costs will never get cheaper. Just curious what you did.

 

[Stan in Oly, WA]

Hi PJH,

The vapor barrier I was talking about was the one on the ground, 6 or 8 mil black plastic sheeting. I can't remember if the batts of fiberglass had a vapor barrier. If they did, it's facing up, toward the living space.

I had the insulation installed rather than doing it myself. The cost of labor was surprisingly low---much lower in fact than I would have been willing to pay to not have to do that awful job myself. My sensitivity to fiberglass has increased enormously over the past 35 years. It bothers me for days now, regardless of what measures I take to protect myself from it.

The installer used twine stapled to the bottoms of the joists to hold the batts in place. That method seems to be the standard around here. I have a 10' wide roll of Tyvek that I thought I might staple to the bottom of the joists to hold the insulation up tighter and to make the crawlspace less of a chamber of horrors. If I don't get around to it before I die, it won't figure on my list of regrets.

All the best, Stan

 

[Stan in Oly, WA]

Thanks for the great responses, everyone.

Stan

 

[Anonymous-0]

Some brands of yellow fiberglass insulation smells like urine. I refuse to use it any more. We would get in trouble for peeing in the corner, because the house smelled so bad. Sometimes hard to convince homeowners cheap isn't always better.