We just moved into the home my grandfather built in 1932. It sat empty for a few before we moved in. But even after ridding the basement of old furniture and freezers and tons of junk, we can't seem to get rid of the constant “cat box” type odor that seems to be part of the cement floor and cinderblock walls. Even after a good scrubbing, the smell eventually returns. The basement is dry, and doesn't look moldy. Most of the space is exposed building lumber, which is old chestnut. Any suggestions?
The issue might be stemming from high humidity, so I suggest taking steps to get that basement humidity down. Other than that, consider repainting the basement with a good quality basement wall-to-floor paint. Those basement walls are very porous, and so is the floor. By painting, you'll lock in some of those odors. Citrus Magic products can help, too - their Triple Action Odor & Moisture Absorber takes moisture out and makes the space smell better, to boot.