Home repair: It's always a good idea to seal cedar

Posted10/16/2011 12:01 AM

Q. We built our home in 2004 and have conflicting opinions as to whether the cedar shake roof should be sealed. Your opinion?

A. It is best to apply a suitable semitransparent stain on any cedar product, be it roof, wall siding, cedar log home, fencing or deck. In my experience and research, the best such product is Amteco TWP, which is specifically manufactured for use on cedar but also is suitable for other types of wood. This is what I am using on our newly pressure-washed, pressure-treated wood deck. Many readers who have used other products have written about their bad experiences and asked what to use instead. The many clients to whom I have recommended, and who have used, Amteco have been very happy with the results.

If there is a Glidden Professional store in your area, you should be able to find Amteco products there. You can also buy it online at www.amteco.com, where you can select the best product for your cedar shakes -- probably the Series 200, since roof shakes are exposed to more weather than siding would be.

Q. We are thinking of building in the next year or two, using ICF walls. Insulated concrete forms seem to be a green, efficient way to go. We realize the cost is higher, $9,000 to $12,000 more. The house would be a walkout plan. The architect says ICF is too costly and we would be better off doing just the basement walls. He said there wouldn't be much difference in the green factor or in savings on heating and cooling using the newer sprayed-on insulation, which is tight around pipes and so forth. Plans can't be drawn up until we decide which way to build because of the difference in the thickness of ICF walls. If we don't have plans drawn, then we can't get an idea of the cost to build, whether it be the ICF or the ICF and regular wood construction.

If you have any thoughts on this or on how we can weigh the two against each other, we would be grateful.

A. Your architect is right. Building the foundation with ICFs (insulated concrete forms, for those not familiar with the acronym) is a good idea, but effectively designed and built stick construction, with closed-cell sprayed foam insulation, is very energy-efficient. It would also be very desirable to sheath the entire framed structure with rigid insulation to prevent thermal shorts through all the framing members.

The advantage of stick-built construction is that it is a lot easier to install wiring or make other changes as the project is under construction. Regardless of how well the project is planned, it is likely you will see things you would like to change as construction progresses.

Q. After reading your column in the Daily Herald, we got some Sikaflex-1a. Cleaned off all the silicone from our shower surround and applied it. We let it cure for the full seven days with the shower door off so it would have good ventilation. It looked great until the first cleaning.

I normally use 3 cups of water, 1 cup of vinegar and some Dawn liquid dish soap in a spray bottle to clean the bathroom. The Sikaflex turned yellow.

Needless to say, I am very disappointed and won't be using it around the tub in our other bathroom. We will be going back to bathroom, mildew-resistant silicone.

A. Yours is the first complaint I have heard about Sikaflex-1a when properly used. Seven days of curing is essential to let the polyurethane compound cure and become resistant to wetting. Something does not sound right in the case you present.

I just finished a long conversation with Sika tech services, and the gist of it is that, if you truly did not subject the caulking to water for seven days, the vinegar is responsible for your problem. Vinegar will cause the compound to "pickle" and change color. Why did you feel you had to use vinegar? I have never heard of vinegar being used to clean caulking before. Water and a mild detergent, such as the one you used, are sufficient.

I have used Sikaflex-1a indoors and out for more than 50 years and never had this problem. Over time -- years -- Sikaflex-1a will turn a very slight gray, which is not objectionable; it looks very much like the color of weathered tile grout. I am sorry that you are disappointed with it.

Sikaflex-1a is such a wonderful product that my favorite contractor and his crews to whom I recommended it a few years ago no longer say that they are caulking something; they "Sikaflex" everything now.

Q. We bought our house new 21 years ago. The bathroom has been painted a few times, and eventually the paint begins to spiderweb and peel. The builder used run-of-the-mill wallboard, and we are thinking the only way to stop this condition is to replace the wallboard with the blue or green kind used in bathrooms. This is going to be a messy job. I suggested tile, but my wife thinks that if paint doesn't stick to walls, how do we know tile will? Any suggestions?

Also, our house is a raised ranch with vinyl siding. We moved the dryer and cut a new hole for the vent. Any thoughts on how to patch the hole so it looks decent? I have the piece that was cut from the old opening, but how do I get the siding to look like no hole had ever been there?

A. You may have excess humidity, which green drywall is unlikely to help. It is more important to reduce the humidity by using the bathroom fan regularly. If you are concerned about forgetting to turn it off, a timer that allows you to choose between five, 10, 20 and 30 minutes would eliminate that concern. If you have not done so, you may want to try a high-gloss enamel paint such as Aura by Benjamin Moore. But for it to look good, you would have to cover the "spiderwebs" to prevent them from being telegraphed through the new paint. Depending on what you call spiderwebs, you may have to do some spackling.

As for your dryer hole, the only way to get the results you want is to replace the affected vinyl siding panel. You may have a hard time matching the color, but vinyl siding can be painted.

Q. I live in a two-story colonial in a Northern Chicago suburb. Half of the basement is a 4-foot-high crawl space with a concrete floor. The remaining full basement space is used for stairway access, a utility/workshop and a 12-by-15-foot activity/playroom. This room was partitioned off from the full basement and includes two drywall walls, indoor/outdoor carpeting, full entry door and crawl space access door. The room was built and passed code, but no insulated drywalls were required on the two external foundation walls. During three of the four seasons, the room temperature is comfortable -- in the high 60s. However, in winter the room doors need to be closed and a 500-watt heater turned on to boost the temperature to the upper 60s.

I would like to investigate applying coatings to the external walls of both the crawl space and full basement that would reduce some of the heat lost through the foundation walls. Are there any coatings sold to homeowners that would provide some insulation, yet not trip any code violations?

A. The rule of thumb is that you can safely insulate exterior basement walls to 3 feet below grade unless you are sure you have a working foundation drain, the backfill around the foundation consists of coarse material to within 12 to 18 inches of the final grade and the final grade slopes away from the foundation to prevent water from pooling or running against it.

The reason for this is that insulating deeper than 3 feet below grade can cause deeper frost penetration, which can crack foundation walls. Obviously, anyone living in mild climates does not have the same concern.

So the crawl space walls can easily be dealt with. It is unfortunate that the drywall walls were not insulated prior to their construction.

In light of the cautionary statement above, is it worth tearing down the drywall to insulate just the top few feet of the playroom exterior walls unless you know that you have met all the criteria and can insulate down to the floor?

You do have another option that can solve the potential problem and allow you to insulate the walls to the floor, although the end result may not warrant the effort or expense. A 4-foot-wide, 2-inch-thick layer of rigid XPS (extruded polystyrene -- gray, blue, pink or green, but not white bead board or polyisocyanurate) can be buried in the ground around the foundation. These panels should be buried about 1 foot below grade at the foundation and slope gently away on a smooth bed, free of stones and other obstructions. They will prevent frost from penetrating deeply and retain the natural warmth of the soil.

Q. I recently read your article about sealing concrete because salt from the roads during the winter was causing problems. However, my problem may be different. The floor in the basement and garage was poured during the cold weather in Pennsylvania. It was a new home that was being built. I remember they used calcium of some nature so it wouldn't freeze. However, now when I sweep the basement or garage floor, I get a powder that looks like concrete powder. It's not a very large amount, but it does this every time I sweep. I was wondering if you are familiar with this problem and if there is something I can do to stop this powdering.

A. There are several possible reasons the concrete surface is dusting: finishing was performed with bleed water still on the surface; condensation resulted when the concrete was poured in winter on cold substrate and with very humid ambient air -- a frequent occurrence at such times; concrete was poured directly over a plastic vapor retarder or clay soil, which increases bleeding of the mixture; carbon dioxide from the use of heating sources such as generators, gasoline engines and salamanders caused carbonation; and insufficient curing.

You can use a high-pressure, gas-powered washer to remove the soft layer in the garage, but that is not practical in the basement. The application of a commercially available chemical floor hardener such as sodium silicate (there are others) may significantly reduce, and perhaps even eliminate, dusting.

Follow-up: I have had a few questions over the years about the best way to remove newspaper ink from kitchen countertops. I have successfully used a Clorox Bleach Pen on laminate and Corian, but not on granite or marble.

The following is a tip from a resourceful Vermont reader who uses Mr. Clean Magic Eraser to remove stains from her countertops. She says: "I've used it on newspaper ink, rust rings, food coloring and red wine stains. I hope this is of some help. My husband and I really enjoy your column."

Another helpful hint to cut out and stash away for future use.

• 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.

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