1. Archive

For a no-sweat garage floor

Question: I want to use my garage as a workshop, but the concrete floor sweats. Is there anything I can put on it that will stop the sweating? Would epoxy work? What would work? There is no vapor barrier under the floor.

Answer: It is true that water vapor comes up through the concrete, and, when enough of it saturates the air in the garage, it condenses on the nearest cold surface, but the garage is getting water vapor from other sources as well, so a vapor barrier on the floor might not cure the sweating. Ventilating the garage regularly _ even daily _ would probably stop most of the sweating, except during the dog days of July and August.

Epoxy is unlikely to work in keeping water vapor from coming up through the concrete; it is extremely difficult to stop such water vapor infiltration.

One thing you could do is lay 6-mil polyethylene plastic on the floor, then pour 2-3 inches of cement.

An alternative is more expensive: Put poly directly on the concrete, then install 2-by-4 sleepers 12 inches on center. Have them gunned in by a professional with a nail gun. Install 1{ inches of Styrofoam insulation between the sleepers, then put on a plywood or any kind of a wood finish floor. The floor will press the insulation against the poly, and the poly will cover the floor tightly and completely, allowing no space for water vapor to enter (and condense).

Two bonuses to this technique: It provides insulation on the floor and provides a resilient floor surface, easy on the feet.

Painting skimcoat

Question: I have a new ceiling of skimcoat plaster on Blueboard. Should I paint it, and, if so, when? Also, do I need a primer on my plastered walls before painting?

Answer: For starters, you don't have to paint the skimcoat ceiling for a while; the plaster will stay white for a number of years. When it gets dirty, you can brush it down with a cloth and paint it with two thin coats of latex ceiling paint. If you want to paint right away, wait two weeks from the time the skimcoat was applied.

There is generally no need for a primer on a skimcoat or plaster wall. Two coats of latex wall paint will do well.

Crayon marks

Question: How can I remove crayon marks from my fireplace brick?

Answer: Scrape off as much as you can with a putty knife or any other type of knife. Put ice cubes on the crayon to harden it, making it easy to scrape or chip.

For what remains, tape a single layer of grocery bag paper over the marks and press the paper with a hot iron; you will see the crayon staining the paper. Take off the paper after a few minutes and see how much crayon was removed. If any remains, put up new paper and repeat the ironing until no more crayon is absorbed into the paper.

Wash off residue with paint thinner. Straight ammonia may work as well as the paint thinner to remove the residue. When working with paint thinner or ammonia, provide lots of ventilation.

Stabilize shelves

Question: The metal shelves in my workroom are sort of tilting over, slanting to one side; in fact, they are sort of racking. How can I keep them straight and keep them from falling over? They really don't seem very stable against the wall.

Answer: Some metal shelves always seems to be pretty flimsy; even tightly bolted they may shake, rattle and roll, but there are ways to stabilize them.

First, check the bolts. If any are loose you can tighten them, and, if they don't stay tight, refasten them with a locking washer between bolt and nut.

Perhaps more importantly, you can secure them to the wall so they will not only stop racking but keep from falling forward. If the wall is made of wood studs and plasterboard, drive screws through the uprights or into the flange of the shelves, but make sure you drive the screws into a stud.

You don't need many screws to do this; four to six or more (depending on the size of the shelves) strategically placed will be enough. After all, they are not supporting a heavy load but keeping it from moving.

If the wall is concrete, you can drill holes in the concrete and fill them with fiber or plastic anchor sleeves. When the screws are driven into them, they will hold as well as if the screws were driven into the wood studs.

Drilling holes in concrete is not easy, but with a masonry bit on a power drill it can be done.