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Oil-based driveway sealer exists, but its use is uncommon

Q. My sister-in-law just had her driveway newly asphalted, after which the contractor immediately applied a sealer. You can imagine how alarmed we were when we read your reply to my previous email advising that it not be sealed for two years. So I called the contractor and requested his side of the story.

He said your comments are correct only if an emulsion (water-based) sealer is used. He said he uses an oil-based sealer that protects the new asphalt and has none of the negative effects of an emulsion sealer. He said he has done this for many years and he is still rated "A-plus" by the Better Business Bureau. He also gave my sister-in-law a one-year warranty on her driveway. I thought I'd better let you know what he said in case he is correct. As always, thanks for all your help in the past.

A. Most seal-coaters have switched to emulsions - to which my earlier answer to you applies. But I contacted my old friend Don Jamieson of PMSI in Worcester, Massachusetts, an expert on all things asphalt-related for his take on the unusual use of an oil-based sealer today.

Here is his answer: "The contractor is correct, although I didn't know that anyone still used the oil-based (solvent) sealers anymore. They are not as available as in the past, and the price has risen substantially with the price of oil. My question would be: Why apply a sealer to fresh asphalt when the protective oils are still in it? That is what you are allowing to evaporate over the couple of years that you leave it to cure. And that is why you need to seal the asphalt then to stop the aging, or evaporation at that time. I suppose no harm done, but would only question the cost to benefit."

Q. We had a new deck installed using pressurized wood late last fall. We want to stain it now before the cold weather hits. However, the deck has gotten dirty over the winter and summer. What can we use to clean the wood before staining? I have had bad luck with pressure washing wood in the past, so I don't want to try that method. Would a solution of bleach and water work? Do you have any better suggestions?

A. If, by pressurized wood, you mean pressure-treated yellow pine, it can be safely pressure washed, using low pressure. On the other hand, softwood decking material, such as redwood or cedar, should not be pressure washed, as these woods can be damaged by it.

The best way to clean any decking material of mildew and any other pollutants is to scrub it with a mixture of equal parts Oxy-Boost and Deck & Patio Cleaner from ecoGeeks, www.ecogeeks.com. Follow directions on the containers.

EcoGeeks products do not contain chlorine and are environmentally safe.

Q. We just moved into a new home last year. It was built in 1957. It's a one-story ranch with a full basement and well-insulated attic. There are two closets (off bedrooms) with rear walls that get very damp whenever the humidity gets high. These walls are internal. One is a common wall with a bathroom tub/shower. At first, I thought that condensation was coming from the bathroom. The other rear wall is a common wall to a hallway. Neither are exposed to the outside.

I checked in the attic yesterday and neither wall has open space above voids between the studding. Both walls have rock lath or drywall over them. They are then covered with a lot of insulation. (I thought there would be open space where I could just remove the insulation, and allow for some airflow.) Do you know whether it would help to put some vents directly into these walls - perhaps at the top and/or bottom or between the studs? Are there vents made for this application? Finally, if your book covers a situation like this, where can I find it? I should probably get it regardless.

A. Adding vents in the closet walls is not the solution. With no open stud cavities visible from the attic, and ample insulation, the problem can't be caused by cold air dropping down in those spaces in the winter. Not only this, but you mention high humidity, which I assume means a summer problem.

You haven't mentioned central air-conditioning, so I assume that you do not have it.

Considering that the closets are internal and that you notice the dampness when the humidity is high, my guess is that the two closets have solid doors and are full of clothes. This would prevent any circulation, as there is in other rooms from open windows or fans.

Try keeping the closet doors open and aim a fan toward the back wall of each closet. Air movement is likely to be the solution.

On a permanent basis, you can hang packets of dehumidifying chemicals found in hardware stores.

Q. In the fall of 2002, I built a small home (24 feet by 50 feet) on a lakefront property in Swanton, Vermont. There was an existing structure there that we tore down, leaving only the stone fireplace, which was incorporated into the new build!

Footings were poured onto a ledge that was roughly 30 inches below grade. A block wall was then built with four 8-by-16-inch vents for circulation placed roughly 16 inches from the inside corner on a 24-foot wall. Construction was 2-by-10-inch floor joists, 16-inch on-center with 3/4-inch Advantek plywood. Exterior studs were 2 by 6 inches, 16-inch O.C. with a truss roof. The house was intended for seasonal use because the water line from the street is too close to the surface due to the ledge and freezing would occur. Plumbing was done so that all lines could be drained in the fall to prevent freezing of pipes.

In the spring of 2003, the homeowner contacted me and said that when the plumber was in the crawl space pressure testing the supply lines, he noted that the soil was quite wet and felt plastic needed to be spread out over the surface.

They contacted me in the fall of 2003 and said that the plastic has water setting on it and had concerns about moisture. I went and looked at the house and there was water sitting on the plastic. I removed the plastic because of the condensation that was taking place. I then took a small excavator and dug a 20-foot trench from the corner of the house to daylight on the shoreline, but was unable to get 100 percent positive drainage because a vein of ledge protrudes up roughly 8 to 10 inches above the bottom of footings. This does drain water in times of significant rainfall.

The following spring the homeowner contacted me again and reported that the soil still seemed to be wet and wondered what else could be done. I contacted my electrician and he installed a direct line fan in the crawl space with a duct line pointing to a foundation vent. This was placed on a timer, which the homeowner has had run for roughly six hours a day for the last 10 years. Vents remain open throughout the year (with the exception of one that is located under the deck and was closed when I checked it on my last visit).

I received a call from the homeowner about a week ago saying that the problem was still persisting and was concerned for the structural integrity of the house. I went and looked at the crawl space and found the following:

• Significant deterioration of main carrying beam (6-by-6-inch posts are settling into beam due to softness from excessive moisture).

• Mold is forming on some of the interior joists. This appears to be random with no particular pattern.

Clearly the main carrying beam needs to be addressed for support of the structure, but more importantly, the moisture issue needs to be resolved along with any additional work. I was hoping to get your views on the situation and potential solutions to this problem.

A. It sounds as if water is leaking into the crawl space, since you found some on top of the plastic. Moisture from the soil would not get on top of the plastic unless the crawl space floor is uneven and the seams in the plastic are inverted, with the lower section of plastic below the higher section.

The plastic is essential to contain any moisture and preserve the framing, but it should be installed either in one piece, which should go up the crawl space walls to a point above the outside grade, or care must be taken to make sure that any seam is properly overlapped by at least two feet, and taped.

Any external leakage should also be taken care of with either grading corrections, curtain drain or some sort of effective waterproofing.

I also question the wisdom of keeping vents open since they admit warm, moist air into the crawl space during spring and summer, especially on a waterfront. Vents were - and are probably still - part of some building codes, but they were discredited decades ago when framing was profoundly affected in Southeastern regions of the U.S.

The National Association of Home Builders' former Research Foundation (now renamed Home Innovation Research Labs) issued the results of an extensive study on this problem and its recommendations in the 1970s.

Control of the soil moisture and of any external leakage are the best ways to deal with crawl space problems.

Q. When our condo was built, the contractor used asphalt instead of concrete for the garage floor. Age has taken its beauty with oil and paint spots, etc. Is there any cleaner I can use to clean the floor up?

A. Paint can be removed with a semisolid paint remover. Be sure to check that it is safe to use on asphalt, as some strippers may damage it. Oil stains can be removed by sprinkling hot water on them and sprinkling TSP-PF crystals on the wet spots. Allow to stand for 30 minutes, scrub with a stiff bristle brush and rinse with your garden hose.

• Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. His book, "About the House," is available at www.upperaccess.com and in bookstores. His website is www.henridemarne.com. Readers can send questions to Henri de Marne's email address at henridemarne@gmavt.net, or to First Aid for the Ailing House, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.

© 2014, United Feature Syndicate Inc.

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