Solid Hardwood, Engineered and Laminate Flooring - stained wood floor

Hello, I am cross posting this in heating, cleaning, flooring and plumbing because I don't know the cause of my problem.

Here's the problem. I am refinishing a wood floor outside my bathroom. (Hallway). After sanding the floor, it released a noxious odor. The sanding revealed a bad stain in the wood too.

Now, this house is a forclosure and was abandoned for 2 years before I bought it. The spot where the stain / smell are at are immediately adjacent to a covered over heating vent. This vent has assisted with rotting out the crappy plywood subfloor of the bathroom, assisted by water, I assume. The rot does not seem to have spread to this stain / smelly area, but you never know. There don't seem to be pipes leaking.

The smell smells like pee. My wife has smelled the same smell elsewhere in the house, near heating vents. It is possible, given the history of the house, that it is in fact pee, from people using corners (YUK!).

I don't think the smell is coming from the vents (since I replaced them last year) but it is possible. It does not seem to be coming from all vents, just near certain ones, leading me to the pee diagnosis.

The smell has lessned since it started, I'm assuming I released it from the wood by sanding.

Ok, so my questions:

1) What could this be? Could it be coming from the vents or from old pee? Or something else?

2) How do I get rid of pee smell in wood floors, short of replacing the boards?
note that the boards do not have any finish on them right now, since I sanded them.

3) How do I get this stain out of the wood? It's darkened the wood in an area, which does not sand out. Can I bleach the wood? If so, how?

thanks, and sorry for all the cross posts.

I actually came on this site to ask a question about my own stained wood floors im now on my final 2 steps. But my floor stain will not dry its been 3 days. Anyways I have had a similar odor in my home and its only in certain spots. I know for a fact what mine is so yours could be too. Male cat urine. They spray everywhere and it is very difficult to get out. I recently had a cleaning company in and they said 1/2 water 1/2 fabric softener would mask the smell in carpet or some other things just spray on and let it dry there. As for my damaged wood floors, wood bleach worked in some areas, sanding the spots worked in others and i have just finsihed staining my floors a dark stain colour to hide the rest. I am now waiting for that to dry so i can varnish which will probably take care and seal in the rest of the odor problems. By now its really not noticable but it could be all the fumes from the stain. I don't know if i have been any help but I hope so. Any experience with stain?????

thanks for the reply - that's the first real advice i've gotten =) i'll try the fabric softner trick & get some wood bleach. i don't know about your stain problem. it *should* dry fairly quickly - might be humidity if it's water based stain ?!? check the label of the can & call the manufacturer too. :D

Fabric softener, as indicated, will "mask" odors not eliminate them. Pet stains in hardwood floors are often permanent. Sanding and wood bleach may be effective on some stains. Staining wood floor with a dark stain can often camouflage stains. Because pets also get urine on walls and baseboards, walls may need to be sealed along bottom with a couple coats of shellac-based primer sealer like Zinnser. Baseboards may need to be removed and a couple coats of sealer applied to the back. Avoid getting water or water-based cleaners on wood floors if there is no protective finish on wood. Water will also stain wood.