QWe have a screened-in cedar deck that we want to have a "natural" appearance. What finish do you suggest to keep it from deteriorating? -- H. Morat

AA clear sealer that will help protect the deck from the effects of moisture and ultraviolet light would be a good choice. These deck sealers are available at most home centers and paint stores under various brand names. A sealer will help prevent darkening of the wood as well as help protect against mildew, splitting and warping.

Most sealers are easy to apply with a garden-type sprayer or paint roller. Before sealing, make sure the deck is clean. If the wood is dirty or stained, a sealer will simply help seal in the dirt. I like Olympic Deck Cleaner, which you apply with a garden-type sprayer, allow to work for several minutes, then rinse off with water from a hose.

Most sealers remain effective on exposed decks for one to three years. Because your deck is partially protected from moisture and sunlight, your sealer might last longer. When the wood starts to darken or absorb moisture, clean the deck and seal again.

Those who want longer life from a sealer might try One Time, whose manufacturer claims it has an effective life of seven years. This acrylic-resin sealer is comparatively pricey (about $70 per gallon, compared with $18 or less for most conventional sealers), but the manufacturer says it is cheaper in the long run because it lasts longer and gives better coverage. One Time can be applied with a brush, roller or airless sprayer (paint sprayer rather than a garden-type sprayer). It is available in clear and several tints. If the deck was previously sealed or stained with another finish, it should be cleaned with a sealer-stain remover. For more details and ordering information, visit www.onetimewood.com or call 866-663-8463.

To make a claim during One Time's seven-year limited warranty, you will need proof of purchase and wood samples showing the problem. You can recover the cost of the sealer or get more sealer. There is no compensation for labor.

We have a concrete patio that butts against the rear wall of our house. During heavy rain, water seeps into the crack between the patio and wall and enters the basement. Someone told us he sealed a similar crack with a tar-like substance but doesn't remember the name. Can you help? -- A. Moumin

The material was probably an asphalt driveway sealer or plastic roof cement, which is used to patch some roof leaks. Unfortunately, I doubt that a patch using materials such as these would last long, because cracks of this type move as the concrete expands and contracts with temperature changes. In addition, the patch would probably dry out and shrink eventually, causing the crack to reopen.

If the crack is more than about 3/8-inch wide, I suggest patching it with hydraulic cement, an expanding, fast-drying cement that is sold at most home centers and hardware stores under such brand names as Fast Plug. Check the patch occasionally to see if any small gaps open along its length; if they do, use a silicone-rubber caulk to seal them.

If the crack is 3/8-inch or less in width, use silicone-rubber caulk to seal it. Silicone rubber is flexible enough to absorb slight changes in the crack. Read and follow the directions carefully when using caulk or other patching materials.

You should also correct any drainage problems that are causing water to flow into this crack. Overflowing rain gutters or improper sloping of the patio could be the underlying cause of the leak.

I have been using filters on my cooling-heating vents to help keep out dust. I change the filters twice a year. I was recently told that the filters can damage my cooling-heating unit. What do you think? -- A. Guininger

Vent filters impede the flow of cooled or heated air into rooms, but I doubt they will damage the unit. The effect would be similar to partially closing a register. Some heating technicians say that high-efficiency filters in the return duct -- at the fan that pushes the air through the ducts -- damage the fan motor, but filter manufacturers say this isn't true as long as the filters do not become clogged with dirt.

Questions and comments should be sent to Gene Austin, 1730 Blue Bell Pike, Blue Bell, Pa. 19422. Send e-mail to doit861@aol.com. Questions cannot be answered personally.