Mill glaze leaves homeowner with paint problems

Q. We put an addition onto our home in 1989. At that time, we had cedar clapboard put onto the entire house. I don't believe anything like Tyvek was put down. We have had trouble from the beginning keeping stain and paint on the house. The paint bubbles and peels off down to the bare wood. It starts within six months to a year after a paint job. The last painter suggested taking everything off down to the bare wood and painting again. At this point, we're inclined to try vinyl or possibly cement siding. However, if moisture is involved, and we cover the house with artificial siding, could we end up with a mold problem? One contractor recommended removing the old siding before putting on the new, and another contractor thought keeping the wood would be more advisable, since there would be more insulation on the house.

A. Diagnosing a stain or paint failure requires more information than you have given me. What was on the house before you installed cedar clapboards? Was it removed, and were there any problems with it or underneath it? What trouble did you have with the stain that made you decide to paint instead? Bubbling paint - if the bubbles contain water - generally indicates that the wood is wet. This can be from internal moisture working through the walls, but that would also have happened with the previous siding, and the omission of a housewrap would have little if any effect on this problem. However, most paint problems are caused by external factors: Does the bubbling and peeling take place all over the siding or only in a few places? Where are those places? Was there water in the bubbles, or are you referring to dry bubblelike blisters? If the stain was a solid-color stain - really a thin paint - and also peeled off, it can be that the cedar clapboards were installed with the smooth side facing out and that they are suffering from mill glaze - a glass-like surface caused by the milling process. The fact that the failure occurred shortly after the clapboards were installed makes me suspect that this may be your problem. That is why I have always installed clapboards with the rough side out. Mill glaze can either be removed by several exposures to wetting or by sanding. If this has not answered the peeling question, please give me a lot more details.

It would be a shame to cover cedar clapboards with either vinyl or fiber-cement siding if they can be coated to last. If the problem has been caused by mill glaze, all paint must be removed, the clapboards sanded vigorously and all sawdust removed by pressure-washing. Then consider applying a semitransparent preservative that will emphasize the beauty of cedar. My favorite coating is Amteco TWP. Visit the Web site www.twp-amteco.com to learn about its excellent coatings.

Q. With the recent dramatic increase in the price of heating fuel, the question of closing up a home while on extended winter vacation takes on a new dimension. Many of us keep a minimum level of heat in a home, perhaps 50 degrees. Now that option is becoming increasingly unattractive. Even 40 degrees will be very costly. I keep hearing horror stories of the damage done to furniture and fixtures by our Vermont winter cold. Are they true? Will my antique furnishings split and crack? Will the cabinets also split and crack? Will the refrigerator never function again? Naturally, I would drain all water, purge the lines with compressed air and fill the traps with RV antifreeze. Your comments would be greatly appreciated, as would reference to any writings on the subject.

A. Yes, all the things you mention will be at risk, except the refrigerator if it is turned off. It is best to keep a modicum of heat, even though all plumbing has been drained or the traps filled with RV antifreeze. Try keeping your house at 40 degrees (5 Celsius), which should be sufficient to reduce energy bills and maintain the thermal envelope of the house.

Q. I have a concrete crawl space, and it is below my living room and kitchen. In the wintertime, my hardwood floors above the crawl space are very cold and drafty. Should a crawl space be insulated? If so, what is the procedure, and can I do it myself? What would I need?

A. You haven't given me much information. How deep below grade is your crawl space foundation? How much headroom is there between the soil and the bottom of the floor joists - 2 feet or more? What is the foundation made of - concrete or blocks? Where do you live? In climates subject to substantial winter frost, it is risky to insulate foundations any deeper than 2 feet below grade unless you are sure that:

• There is a properly functioning foundation drain.

• The backfill is made with coarse material and not with heavy native soil.

• The ground slopes away from the foundation to prevent deep water penetration that could freeze and push the walls in - a greater risk with block foundations than with concrete.

Knowing these caveats, it is usually easier and less expensive to insulate the walls of a crawl space than the spaces between the floor joists because you work on your knees rather than on your back. Insulating between floor joists can also run the risk of condensation forming and being trapped within those confined spaces. This can cause serious problems if allowed to continue undetected for long periods of time.

If you can get sizable sheets of 1-inch-thick rigid insulation into the crawl space, you can adhere them to the foundation walls with daubs of Styrobond or a polyurethane caulk as long as you clean the spots before applying the adhesive. Use extruded polystyrene (XPS - blue, gray, pink or green, but not white beadboard known as EPS). Be sure to insulate the band joists with 6-inch-thick (R-19) fiberglass with an integral vapor retarder. Staple its flanges to the sides of the joists. If you can't bring rigid insulation panels into the crawl space, you can insulate the walls with R-11, 13 or 15 fiberglass with an integral vapor retarder. Staple the top of the batts to the mudsill and let the batts drape down the walls. Staple the vapor retarder's flanges together to form a solid blanket.

Q. We have a 1950s ranch with an attic that has pull-down stair access. The attic fan that is installed now is a portable, plug-in type. We'd like to replace it but have seen exhaust fans that run from $200 to $1,000. How do we know what we really need, what will be most cost effective and which supplier to use? Be generous with praise and careful with criticism!

A. I will try to heed your admonition but will restrain myself from gushing with praise. Am I to assume that the existing fan is sitting on the attic's floor, perhaps near a louver, and supposed to draw air from an opposite louver? If it works, and you are happy with the results, why bother replacing it? If you need to replace it, you don't need an expensive model. Most reasonably priced fans today are good and will last a long time. Be aware that attic fans need to have an intake of net free ventilation area (NFVA) that satisfies their cubic-feet-per-minute (CFM) rating or they will draw air from the conditioned space below, wasting energy if you use air-conditioning. A more eco-friendly and economical way of keeping the conditioned space cooler in summer - and warmer in winter - is to add significant amounts of insulation to the floor of the attic. If the attic is used for storage, the floor can be raised to increase the depth of the insulation.

• Henri de Marne's column appears Sundays. He 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 e-mail at henridemarne@gmavt.net.

© 2008, United Feature Syndicate Inc.