Home repair: There’s no clear winner when choosing floor varnish

Q. We are planning to hire professionals to refinish our hardwood floors. They were originally finished long ago with an oil-based polyurethane varnish. Now we are having a disagreement over whether to ask them to use a water-based polyurethane or the traditional oil-based polyurethane.

Based on an article I read many years ago, it’s my belief that the oil-based polyurethane is a more durable product. Things I’ve read lately suggest using three coats of water-based polyurethane but only two coats of the oil-based polyurethane, which indicates an extra coat of the water-based product is needed to compensate for its reduced durability.

I’ve also read that the oil-based polyurethane penetrates the wood, thus accentuating the grain and giving the surface a more natural shine, and that it’s easier to repair damaged spots with the oil-based product.

Certainly, the fast drying time and reduced odors of the water-based polyurethane mean you can occupy the living space sooner.

Is there a durability issue that’s resolved with extra coats of varnish? And if so, does the choice then come down to which finish we like the “look” of best? What’s your recommendation?

A. The reason three coats of water-based polyurethane and only two coats of oil-based are recommended is that each application of the water-based varnish results in a thinner film, so three coats produce the same thickness as two coats of oil-based varnish. The water-based varnish is no less durable.

Oil-based varnish will accentuate the pattern of the wood, but each coat will need to dry at least overnight. So the rooms will not be usable until the third day, if then — the drying time depends on the ambient temperature and humidity. With a water-based varnish, three coats can usually be applied the same day.

The decision really depends on what is more important to you — “the look,” as you put it so well, and the inconvenience of the oil-based varnish versus the convenience of the water-based varnish.

Q. In a past article, you suggested using the Positive Rite Flow drip edge on the roof. We are planning to put a new roof and gutters on our home. I found that the Rite Flow drip edge made by Lamb & Ritchie is distributed only out East. I live in the suburban Chicago area, and when I called Lamb & Ritchie, I was told the company doesn’t have a distributor in the Midwest. Is there another drip edge you recommend that is similar to the Rite Flow and available in our area?

A. I am sorry, I don’t. The Positive Rite Flow drip edge is sold through building supply houses. It is the best drip edge around, preventing water from the roof from crawling behind gutters by surface tension. Consider asking local building supply houses if one of them would order it for you and would become the local source for it.

If this fails, ask your roofing contractor to make a piece of metal with a drop lip at a 45-degree angle, which can be installed over a regular off-the-shelf drip edge and hang over the gutter, as the Positive Rite Flow drip edge does. An ice and water protective membrane should be applied over both drip edges.

Q. We are considering entering into a 20-year leasing agreement to have solar panels installed on our roof. It is a fixed rate, and we are pleased with the potential savings the company is projecting. We also like to do our part in conserving energy.

If we agree, the company will be installing 15 SunPower solar panels on our metal roof. The leasing agreement covers protection rights to the owner for installation and removal.

Based on your experience, is there anything we should be concerned about or make sure the installers do when they put the panels on our metal roof? Are there things we should consider before entering into the leasing agreement?

A. The obvious and most important thing to make sure of is what the installers will do to prevent roof leaks, and how they will repair your roof if you decide to have the panels removed later for whatever reason, including a request from a prospective buyer. It is a lot harder to repair a metal roof — and make it look good — than a shingle roof.

Have a lawyer check out the leasing agreement. You also should check out the firm planning the installation — how long has it been in business, and how many installations has it done? Can it provide a list of references for installations done recently and as far back as the company has been in business? Call the references to find out if the work was done on schedule and cleanly, if there have been any problems with the installation and functioning of the system, and if the company has been responsive to calls for repairs or adjustments.

Otherwise, congratulations for going ahead with what should be done on all commercial, industrial and institutional roofs in the country. There are so many large, flat roofs that should be covered with solar panels. It is the wave of the future, which we have long neglected, and it’s time we catch up.

Q. I enjoy reading your article in the Sunday newspaper. I own a 74-year-old brick house. At some point in time it was painted white, and it has been repainted many times since. There are several areas where the paint will not stick to the existing paint. It is much, much worse with the grout in these places.

The problem areas are primarily 1 to 5 feet up the walls and where there is sunlight for perhaps half of the day. There are no problems higher up the walls.

It is always the same areas that peel, every two to three years. Judging from the look of the grouting, it appears that in the two worst areas there had been repair work.

Is the problem a matter of poor preparation? Moisture? I sure would appreciate your help!

A. It sounds as if the peeling may be due to inadequate surface preparation before the paint is reapplied. Back-splashing from roof water that hits the ground and bounces onto the wall is also likely, since the peeling is on only the lower parts of the walls.

If there is even the smallest crack in the paint, water will penetrate and soak into the bricks. That may occur at the mortar joints where the bricks’ sharp edges may not hold paint well. Once moisture has penetrated the bricks, paint will peel.

It may also be possible that the surfaces were not thoroughly cleaned before repainting. Any amount of soil from the splashing will prevent paint from sticking over the long run.

You can power wash the problem areas to remove most of any pollutants, then scrub them with a solution made of 1 quart fresh Clorox bleach and 1 cup TSP-PF detergent per gallon of fresh water. Power wash again to remove the solution and whatever it dislodged.

Allow the areas to be painted to dry thoroughly if you are using an oil-based paint. This may take awhile, as the surface of the bricks may feel dry even though moisture may still be within the bricks. Slight surface dampness is OK if you use a latex paint, but not moisture within the bricks.

The best paint to use may be a cementitious coating such as Super Thoroseal, which you should be able to find at masonry supply houses and some hardware and box stores, although the selection of Thoro products varies depending on customer demand. Thorough products can be viewed at www.thoroproducts.com. Click on Where to Buy.

Q. I enjoy reading your weekly column in the newspaper. I know you’ve replied to many caulking issues in the past, but I’m unsure if you’ve already answered the following question pertaining to the adherence of caulk around the bathtub.

Ever since we had the bathtub and tile replaced, I’ve had to recaulk about every six months (or when I simply can’t stand to look at the condition of the caulk anymore!). My methodology is as follows: I remove the old caulk, clean the area, let it dry and then apply the new caulk, which I allow to dry the required length of time before using the shower. The caulk I’ve used the last few times is DAP Kwik Seal Plus Premium Kitchen & Bath Adhesive Sealant with Microban.

At first, I thought mold had developed on the caulk, but that’s not the case. The caulk is actually disintegrating in spots, and what you see behind the caulk is the tile grout. I’ve enclosed five pictures that I hope will provide a clearer explanation of my problem. OK — stop laughing. I already know I’m not proficient at caulking! Can you tell me why this is happening?

A. Thank you for sending the photos; they help a lot. And I am not laughing. Caulking is not an easy job, and I have seen professional jobs, including some of my own, end up not looking very good. It’s almost an art.

From your photos, it looks like the original caulking job was done with silicone, which would explain why the caulking did not last. It also would make it impossible for any other application to stick properly unless the silicone and all of its residue were totally removed, which you may attempt using WD-40 or DSR-5 (www.dsr5.com) and a putty knife, paper towels, clean rags — whatever works best.

Next, you need to make sure the crack has no mold or mildew and is clean and completely dry.

As to which product to use, the silicone industry has done a great job of selling its product as the best, and you’ll find most “advisers” recommend it as the product to use. But in my 55 years experience in the construction business, I have seen innumerable silicone failures in many varied applications. Silicone caulking has a tendency to separate from surfaces after awhile, which allows water penetration. Silicone is also prone to mildewing, which cannot be removed. And contrary to some claims, it is quite easy to remove silicone by simply peeling it off if you free one end. (Try that with polyurethane — the choice of commercial builders!)

Some time ago, I tried DAP Kwik Seal Plus Premium Kitchen & Bath Adhesive Caulk with Microban because of its claim that it is mildew-proof. I caulked half of our tub with it and the other half with Sikaflex-1a polyurethane caulking/sealant, which I have used for more than 40 years in all applications.

I decided to give DAP’s product a try because some of my readers had reported that Sikaflex-1a turned pink after awhile, or simply did not remain as white as when first applied, which does happen if Sikaflex-1a is not allowed to air-cure without being repeatedly wet for a week. (This is hard to do if your tub or shower is the only one in the house.)

Although the DAP caulk remained sparkling white and did not mildew, I found that it began to peel off the wall in about a year, whereas Sikaflex-1a was still firmly stuck to both the tub and the wall.

You also can buy Sikaflex-1a tubes for about $5 from DHC Supplies (www.dhcsupplies.com). Home Depot stores do not carry Sikaflex-1a but do sell Sika Construction Sealant, which looks quite the same to me.

Ÿ Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. Write to him in care of the Daily Herald, P.O. Box 280, Arlington Heights, IL 60006, or via email at henridemarne@gmavt.net. His book, “About the House,” is available at www.upperaccess.com and in bookstores.

© 2012, United Feature Syndicate Inc.