If you have anything at all to add to this discussion please feel free to chime in. My wife and I'll be closing on a 44 year old home with a crawlspace in a couple of days and I need some peace of mind.
There are two problems, likely related. Upon entering the house for the first time all three of us - me, wife, agent - noticed an odor. My agent wondered where the litter box was, thinking it was a cat urine smell. Just yesterday I noticed that the smell was on my hands two hours after crawling around in the crawlspace without gloves.
A couple of problems were discovered that may be the cause of the odor. First, the condensate line from the AC/Furnace drained right into the crawlspace, dripping directly on top of a return duct that was insulated with a brown paper backed fiberglass looking insulation. It was a wet, messy puddle.
Second, the dryer vent hose had fallen off and all the lint from the clothes dryer was collecting close by. The home inspector believed that by fixing these two problems the odor would go away.
On Wednesday two contractor sized garbage bags filled with wet insulation and dryer lint were pulled out of the crawlspace. Then a 50 lb bag of lime was spread around the damp areas.
The guy doing the work noticed another dripping sound. He placed a bucket under the drip. Turns out that there was a loose fitting inside the house and the owner tightened it up on Friday.
I got under there myself twice on Friday. The approx 1 gallon bucket was almost full. I heard no drip. There was a puddle of water and lime on top of the return duct. I came back a few hours later and the puddle of water was mostly gone, but the white lime was still damp.
A few other notes:
- I noticed that I could smell the PVC bonding solvent when very close the newly installed condensate drain line. Figured there must not be too much air movement through the crawlspace if that odor is still present 48 hours after the repair.
- There is no vapor barrier installed
- The rest of the crawlspace is dry as a bone, no other moisture problems whatsoever
- Automatic vents are installed. Two on each side of the house, maybe more.
- One of the heat/AC vents is not sealed and must be leaking a lot of air.
So, we've got this musty smell inside the house in some places. We've had a bunch of things going on in the crawlspace, that have been recently repaired.
I'm betting that what's been done so far will eventually eliminate the odors I'm describing once enough time has passed for the space to dry up good. Plus, I can do more like sealing up the heater vents, putting down a vapor barrier, and possibly installing more vents or fans in the crawlspace.
Most important question: is there anything else I need to be concerned about before closing on this house?
One longshot question: could the front door being out of alignment be in any way related? The smell is most noticeable around the front entrance. A nearby closet door is out of alignment too. Rest of the doors in house are pretty square.