Q: I own a contemporary house with a dirt-floor crawl space under part of it. Recently mice and voles have tunneled into the floor from the outside. Pest control has been called in to deal with them, but I want to cement over that dirt floor. The crawl space is hard to access, you can’t stand up in there, and the surface is uneven. There is even bedrock ledge in part of it. Should my husband cement over the floor by hand, bit by bit? We don’t have a lot of money to throw at this. The space is roughly 20 feet by 20 feet. Any ideas much appreciated!

SANDY EATON, Lexington

A: A concrete slab laid by hand, even a thin one, is not worth the miserable hard work your husband would have to do. Having a pro do it is best but more expensive than you’d like. Try this: Buy sheets of polyethylene or vinyl, the thickest you can get, and lay them on the dirt with the extra going up the sides. Weigh them down with heavy timbers set against the walls, and see what happens.

Q: I have owned my condo for more than a decade, and the number of cracks in the plaster walls has increased tremendously the past few years. I would like to repaint, but the walls will need to be replastered. It was suggested to me that 1Ž8-inch sheetrock be installed, plastered, then painted. Is this correct?

SANDRA, Salem

A: I think that the plaster job is a skimcoat on blueboard, but why the number of cracks has increased is a good question. Perhaps the "skim" wasn’t the right thickness? Call a skimcoat plasterer to see whether he or she can apply another coat or may have to add an underlayment.

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