Ammonia smell in new home, not animal urine.
I have a problem in a new home we finished in December. After two months of occupation, the homeowners were complaining of an ammonia smell in a closed, heated, unused attic storage space. We opened the windows for a few nice days in February, thinking it was off gassing that accumulated in the closed space. This week, the wife noticed the smell was back and in more rooms upstairs. Windows have been open and closed over the last few weeks and the A/C wasn’t charged until yesterday, so no leaks there.
Full disclosure: 4500sft two story all finished over 1800 unfinished, conditioned basement. Wood framed 2×6 exterior with blown fiberglass walls, sheetrock inside osb outside with xps foam over that. All cedar exterior siding. The attic is blown cellulose unvented. Asphalt shingles. The house has an air change rate of 2.1 ACH. No HRV(I know). Wood burning fireplace on ground floor used daily for Seven months now. We used it during construction. Wood burning remote boiler heats the heat exchanger from outside. One propane appliance(stove) with continuos pipe from tank. Any questions? Diagnose away.
Replies
Kinda sounds like you got hold of some Chinese drywall.
Any sort of product containing phenoic resins will outgas an amonia smell.
Did you wet spray cells? If so the fire retardent could be ammonium sulfate and that could be the cause of the smell.
Could also be a sewer leak that could be determined with a smoke test.
KK
UPDATE
I'm Sure deadnuts has done this before and is just waiting to tell me what I've done wrong, but here goes. We couldn't get the smell out with mere ventilation, so I thought something was continuing to cause the problem. I was lead to believe(from interenet searches) it was probably the Fiberglass in one form or another, but it i could not smell it in any one place more than another. The Owens Corning rep stated it would be a moisture problem if it was the fiberglass and Fiberglass is OK to use with non vented assemblies. Of course, The Rep had other, more probable causes.
To be thorough, I decided to test it ALL products. MYintifically. I took a sample of everything, Fiberglass blown, Fiberglass Batt, Fiberglass duct wrap, Cellulose blown, OSB, Drywall with and without paint, Closed cell foam, Open cell foam and Stained poplar trim. I took a scientific handful of each and place them in a sandwhich bag. After mentally recording the smells, I left this bag in the sun to "cook" for an afternoon. There was no change in smells across the board, at least no Ammonia. Next test, 30 seconds in the microwave to simulate rapid heating(HAPPY WIFE ALERT). No change in smell, no Ammonia. Next test, Moisture. Starting with 1/8 teaspoon per bag, I added tap water, then heated in microwave. No significant change in any but the Closed Cell Foam. Still no ammonia, but the closed cell, heated with moisture, tended to smell like freshly sprayed foam. Curious, but that tells me I have no moisture/heat build up where the close cell spray foam is in the house, because I have no "FRESH" smell there. Not scientific, MYintific. I continued to add 1/8 teaspoon increments and heat until the samples were soaked. Still no change in smell other that the Closed cell which got no worse after the initial change. STUMPER! After all this, the smell was no better or worse in the house. I was thinking that because NH3 is lighter thatn air it might be coming from below. But the ceiling permeability in the garage would be the same as the ceiling permeability in the attic, painted drywall. It should have gone up through there also.
Next, I went for fresh product. I sampled fresh bags of Fiberglass blown, Fiberglass Batt, Fiberglass duct wrap, and celluose blown. I went with these because the other products were more familier to me and could be tested later. I used the same process with the same brand of sandwhich bag and no smell change after sunlight with no water. No change after microwave with no water however I may need a new microwave or my wife needs a new husband. Next, moisture no heat, nothing. Next moisture and heat. By now you think I am rambling, but I can't have a supplier doubting my findings. I needed to be thorough. Which paid off. I created the Ammonia smell!
When Green Fiber(manufacturer) CELLUOSE is heated with moisture content it offgasses an Ammonia smell. One Handfull of product and 1TBS of water in a plastic sandwhich bag produced an ammonia smell with 30 seconds of microwave heat. My supplier said the celluose was good for non vented roof assemblies, however, after further review, it seems not to be the case in my climate zone. The manufacturer claims only in zone 1-3 is there product OK for nonvented assemblies. We are Zone 5.
New questions: Was this enough of a testing procedure? Since my test of the old stuff didn't bring the smell, is the offgas over? Should we now ventilate the airspace? Should we replace the celluose with fiberglass? At whose exspence is this? Should I write this up for the Mag?