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Problem-Solving Subfloor

If you're looking for an easy way to install a finished floor over a concrete slab, you might consider the DRIcore Subfloor System. The 2x2-foot OSB panels have a layer of dimpled polyethylene that raises them off the slab. The resulting air space promotes drying and reduces the possibility of mold and moisture damage. The tongue-and-groove panels lock together without adhesive, and the manufacturer claims that fastening the panels to the slab is unnecessary in most cases. The manufacturer provides small "leveling squares" for shimming low spots in the existing slab. The system sells for about $1.25 per square foot. DRIcore, 866/976-6374,


Smooth Transition

Behind most clothes dryers you'll find dryer vents with distorted hose and tight bends that reduce drying efficiency and trap lint. The Dryerbox eliminates those problems by replacing a gauntlet of elbows and kinked hose with a smooth connection recessed into the wall. It not only increases efficiency and provides a more finished look, it also gets the dryer closer to the wall for additional space in tight laundry rooms. It's available in two sizes, the standard 4 1/4-inch-deep model and a 3 1/2-inch model for 2x4 framing. Just make sure to get 4-inch oval pipe if you're planning to use the smaller size. It sells for about $20. In-O-Vate Technologies, 888/443-7937,


On the Edge

A vented ridge combined with vented soffits is generally considered the best way to get hot, moist air out of an attic space, but what do you do when you don't have an overhang? The best solution I've seen is the Vented Drip Edge from Air Vent. According to the manufacturer, the heavy-gauge louvered drip-edge was designed with contractor input, so it performs well and it's easy to install. It's available in white, black, brown, and mill finishes and provides 9 square inches of ventilation per foot. The 10-foot lengths sell for about $20. Air Vent, Inc., 800/247-8368,


Sturdy Spout

Like a lot of suburban kids, we had a basketball court on the back side of the house when I was growing up. One of the neighborhood's best guards was an aluminum downspout adjacent to the hoop — it sure took a beating defending the net. To keep your customer's downspout out of similar danger, you might try ReplaK Vinyl Gutters & Downspouts. They have the same profile as aluminum K-style gutters, but their vinyl construction shrugs off impacts better than aluminum. In addition, it won't corrode from salt air or pollution. A complete ReplaK gutter and downspout system runs about $1.90 per foot. Genova, 800/521-7488,

On the Job: Acid-Staining a Garage Floor

by Calvin Wong

Our company builds spec houses, and one of the things we do to make them appealing to buyers is to acid-stain the garage floors. When customers walk in to one of our garages, instead of plain concrete they see a floor with an attractive mottled pattern.

Acid stain is made from water, acid, and inorganic salts. It doesn't contain any pigment, but if you put it on cured concrete, it colors the surface layer by reacting with the minerals in the slab.


Acid stain can be applied with a brush, but you need to work fast enough to maintain a wet edge.

According to manufacturers, you're not supposed to stain concrete until it has had time to cure. This means you should wait at least 28 days after the material is poured. That's not a problem for us because we pour garage slabs early in the job, so months go by before we're ready to stain.

No matter how long you wait, it's important to keep the slab clean. You don't want it to get contaminated by things like grease, oil, drywall dust, or paint. We cover slabs with a layer of waterproof paper almost as soon as they're poured and finished. Late in the job, when it's time to stain the floor, we peel up the paper and wash the slab with plain water. We give it a day or two to dry, then we apply the stain.


Acid stain changes the color of concrete by reacting with the chemicals in the slab.

A lot of companies make acid stain, but we use a locally manufactured product called ConSov (Varni-Lite Coatings, Hayward, Calif., 510/887-8997). It costs about $50 per gallon and can be applied full strength or diluted 50/50 with water. If you dilute it 50/50, a gallon will cover about 400 square feet. We usually dilute it, because that lightens the color of the dark brown stain that we typically use.

There are many ways to apply stain to slabs, but we've settled on using a brush. On one of our earlier jobs, we tried using a mop, but it picked up too much acid and left visible run marks on the finished floor. The same thing happened when we tried a paint roller.


The wet stain is starting to darken this area of floor, but the earlier drip — the brown spot — will probably show through.

We like the effect we get by applying the stain in an overlapping figure-eight pattern. You have to be careful not to drip stain on the slab when you lift your brush from the bucket. You can brush over drips, but they will still be darker than the surrounding area.


After the stain dries, the author scrubs with plain water to remove the surface residue.


The finished slab is shown here with two coats of sealer.

The stain goes on clear, but once the chemicals start to react, the concrete changes color before your eyes. We usually let the stain dry overnight and then wash down the slab with plain water to remove the surface residue. Even though there's no pigment in the stain, there will be some color in the wash water. We give the slab another day to dry, then apply a clear water-based sealer. The sealer creates a surface sheen and greatly intensifies the color of the concrete. It goes on milky but dries clear. We usually apply two or three light coats, each about a day apart. It's important to apply thin coats; the sealer will remain milky looking it you put it on too thick. Where the homeowner drives on it, the sealer will eventually wear through, dulling, but not damaging, the color of the concrete. You can renew the color by cleaning and resealing the slab. It takes us 10 to 12 man-hours to stain and seal a 500-square-foot slab.

Calvin Wongis a site manager for TK Construction in Oakland, Calif.