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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Do It Yourself: Consider pair of options with deck-on-slab

Gene Austin McClatchy-Tribune

Q. We have a concrete-slab patio that is in good shape but ugly. We’d like to build a wood deck on top of it. Is that possible?

A. It can be done and there are a couple of options, but the first thing you should do is contact the building-code department in your municipality and learn what regulations might apply.

For example, you might be required to provide corner support posts with footings below the frost line for your area. But in general, a deck-on-slab is built by constructing a framework of pressure-treated wood which rests on the slab and provides a nailing surface for the deck boards.

The slab (and finished deck) must be sloped slightly to provide drainage away from the house and should not interfere with doors that open onto the patio. For best results, the slab should also be free of cracks, depressions and humps.

If the finished deck is too thick, it can also create an awkward or dangerous step at the edge.

Problems that need to be solved also include moisture that can collect under the framework joists, causing eventual rot or deterioration in the wood framework.

Spacing between the framework joists depends on the material used for decking. If regular treated-wood decking is used, joists can usually be spaced on 24-inch centers, but composite decking requires 16-inch spacing because composites are structurally not as strong as treated wood.

Another option is to use wood deck tiles over the concrete. These tiles are made of various hardwoods such as ipe, sometimes of pre-finished composites in various wood tones, and come in various sizes up to about 20 inches square.

The tiles interlock to prevent movement and are simply laid in place over the concrete. They are sometimes recommended for dressing up concrete apartment balconies. Prices vary widely; some tiles I checked on the Internet ranged from $5 to $12 per square foot.

To view a sample selection of tiles, visit For more prices and sources, search the Internet with the words Wood Deck Tiles.

Q. I have a fiberglass bathtub that has developed a yellow ring that I haven’t been able to remove even though I tried numerous cleaners. Can you help?

A. This sounds very much like a hard-water ring caused by minerals in well water, possibly rust from high iron content.

Some of the cleaners you used should at least have had some effect on the ring. However, it is important to remember that fiberglass is rather easily damaged and that you should never use an abrasive cleaner to try and remove stains.

Also, you should test any cleaner on a very small area to see if it helps remove the stain without damage to the fiberglass.

A cleaner that might help is ZUD, which you can buy at many supermarkets. Before using ZUD, read the directions and cautions on the label; this is a strong cleaner and must be used with care. In addition, use only gentle scrubbing action on fiberglass.

If this doesn’t remove the ring, you might need to get the tub refinished or learn to live with it.

One way to keep hard-water rings and stains from forming in a bathtub is to wipe it out with your bath towel after every use.

If you continue to have staining problems, the best bet is to have your water tested and determine exactly what minerals are at fault.

Q. My older refrigerator seems to be running a lot more often than it used to, and I think it is adding to my electric bills. I’m not ready to replace the fridge at this point, so is there anything I can do to fix this?

A. There is a good chance your refrigerator-door gasket is deformed and not making good contact when you close the door. This lets warm air leak into the fridge and cold air leak out, increasing the running time.

A very old but good test is to put a dollar bill under the gasket at several points and close the door. If you can pull the buck out easily, your gasket is not making good contact.

This can sometimes be corrected by tightening or adjusting the door hinge screws, but more often it means you need a new gasket. Some dealers, such as Sears, have parts or you can check

Gaskets often come with installation instructions; if yours doesn’t, visit and enter Refrigerator Door Seal in the search space.

Questions and comments should be emailed to Gene Austin at Send regular mail for Gene Austin to 1730 Blue Bell Pike, Blue Bell, PA 19422.