Be careful with structural eaves

Q. Our home, built in 2000, has two eaves that are accessed through our master-bedroom walk-in closets. These eaves are above the garage, one on each side of our master bath. We would like to finish the eaves to expand our living space, but wonder if there are reasons why we should not or cannot. There are soffits in each eave, which we are aware are used for ventilation. We would appreciate your advice.

A. Although unlikely, assuming that you want to remove the knee walls to enlarge the space, you must make sure that they are not structural (helping to support the rafters if they were not designed to be "free spanning" from eaves to ridge). If your roof is built with trusses, you can remove the knee walls safely.

If the ventilation from the soffits has an uninterrupted air space to a ridge vent, you can simply install baffles from the soffits to where the knee walls are attached to the rafters. If the rafter spacing is 16 inches on center, avoid using any thin foam baffles that only provide 8 to 9 inches of ventilation, and can easily collapse under the expansion of fiberglass batt insulation.

A better system is to tack 1-by-2-inch wood strips to the sides of the rafters against the roof sheathing and use 1-inch-thick rigid insulation as a baffle. If the rafters are spaced 24 inches on center, or you have trusses, off-the-shelf foam baffles are OK, as they are stronger than the narrower ones because they have a stiffening leg in the middle. They also offer more ventilation area. Then insulate between the rafters or trusses and staple a 6-mil plastic vapor retarder to the bottom of the framing members.

If there is no connection between the soffit venting and the ridge vent, the ventilation is not effective anyway. In that case, I would not advise the use of fiberglass insulation. Closed-cell polyurethane is safer, but expensive. Instead, try layering 2-inch-thick rigid insulation, making sure that you leave a 1/4-inch space on each side along the framing members and then spray foam (Polycel or Great Stuff) to fill those spaces. If the length of the roof framing members in the eaves crawl spaces is longer than 8 feet, be sure that you alternate the cross seams and foam all of the ends. The goal is to prevent any moisture from reaching the roof sheathing. This is particularly important because there is an adjacent bathroom.

I cut out your column on caulking a tub, but unfortunately misplaced it. I am a single woman trying to save some money by caulking it myself. Can you tell me the best caulk to use and if there is any caulk that you don't have to use a caulking gun with?

A. I have used DAP Kwik Seal Plus Premium Kitchen & Bath Adhesive Caulk with Microban with great success. It comes in a squeezable tube; perfect for what you want. You may wish to check the DAP Web site, www.dap.com. Click on "Products," "Caulks and Sealants" and then "Kitchen/Bath." You will see several choices. The advantage of the caulks with Microban is that they contain a mildew-resistant ingredient.

Could you please give me the name of the caulking you recommend for bathtubs? After removing the old caulking, I have used DAP Kwik Seal two or three times. After a few months, this caulking has come up and I have had to re-caulk.

A. I have had great success with their DAP Kwik Seal Plus Premium Kitchen & Bath Adhesive Caulk with Microban. It has held up very well on our tub for several years without separating from the cast-iron tub or the wall finish. Did you thoroughly clean the surfaces before applying the product you used? Any residue from an earlier silicone-based caulk may have been responsible for your problem.

A product that is claimed to remove old silicone caulking is Digesil Gel that de-polymerizes the silicone so it can be wiped off the surface. The manufacturer's Web site is rpm-technology.com.

We read your recent response to a question about caulking material. We would appreciate it if you would comment on the following caulk (marine caulk), which we've been using around our house with good results so far. It's called Boat Life by Life Industries, boatlife.com. The label says it is mildew resistant, fast curing, nonshrinking. It can be used above or below a waterline. Says it will not corrode or yellow. Adheres to fiberglass, metal, wood, aluminum, nylon, etc.

A. It sounds wonderful. I have not used it, so cannot comment on it.

There was an article by you about a water softener that does not use salt. I am actually interested in the Web site you listed to check out the product claims.

A. I believe you are referring to Kinetico home water systems. Their Web site is kinetico.com.

Our home is in need of new carpeting and my allergies have worsened to the point where I can't walk into a carpeting store or newly carpeted home or business without getting ill. My problem may be out of your realm of expertise but worth a try for your help. We have heard that there is available carpeting made from ground glass and other materials that are safe for people with extreme allergies and environmental sensitivities. We've had no luck when checking with local stores for manufacturers of this type of carpeting. Might you know of any such product? We would rather not go to all hardwood floors as we like and prefer carpeting, especially in the winter months.

A. Interestingly enough, I have heard of a German study that mentioned air in homes with hardwood floors is less environmentally safe than the air in carpeted homes. The reason is quite interesting, and will be, for sure, decried by hardwood-flooring manufacturers. Most types of carpeting generate electrostatic electricity that attracts the dust particles in the air, whereas hardwood floors do not. I've noticed that TV screens in rooms with hardwood floors becomes covered with dust every time it is turned on and off, but televisions in carpeted rooms remain less dusty.

For the air in a carpeted room to remain healthier, the carpet needs to be vacuumed more frequently either with a whole-house system that discharges to the outside or with a HEPA vacuum cleaner. I have not been able to find out anything about ground-glass carpeting. There is carpeting made with corn oil instead of a petroleum derivative, and it is supposed to be more environmentally safe. Nylon is also supposed to be less allergenic than other materials.

What can I do? I have Pergo Laminate flooring in my kitchen. I have always washed it with only water as the manufacturer suggests. However, I had my wall-to-wall carpeting cleaned in the dining room and walked barefoot on the kitchen floor, which caused stains. The carpet was cleaned using the OxyMagic System. The carpet is great, the kitchen floor is awful. How can I rescue my kitchen floor?

A. That's a new one for me. Pergo and other laminates on the market have polymer finishes that are supposed to be impervious to most stains. I assume that you have tried washing the floor with water as soon as you discovered the stains. I have checked with people in the flooring industry, and they are as baffled as I am. My only suggestion at this time is to contact the carpet-cleaning firm and ask them if they have any idea what could have caused these stains. Sorry I can't be of more help.

We purchased a brand-new home four years ago. The kitchen had stick-on tiles and the hallway had carpeting. We had someone pull all that up and lay porcelain. He pulled up the old floor and glued and screwed cement board down before laying the tile. Now I see the grout is cracking in quite a few places right at the edge of the tiles (We also have a 90-pound dog, which is the reason we took the carpeting out). Why would the grout be cracking?

Also, we were supposed to seal the grout after he did the flooring, and my husband only did a third of the floor. The floor has a light grout on it and some is a different color. Can I stain all the grout darker to make it look the same? Will the grout that has been sealed take a stain and what kind of product would I use?

A. When you say that the grout is cracking "right at the edge of the tiles," are you referring to the perimeter of the tile installation? If so, the installer did not place any movement joints. If you are referring to the grout around individual tiles, there is either a grout, adhesion or structural problem. An experienced tile installer should be able to discern which is responsible for the grout cracking. As for the seal/not sealed issue, obviously, the problem was caused by sealing only one-third of the floor. That, after four years, is now a permanent condition. Any attempt to stain or color the grout is likely to produce another floor with two different grout colors - especially since the sealed floor may reject any attempt to stain or color. The entire floor should be cleaned professionally (using products made by the manufacturer of the original sealer, if possible), and after it has dried sufficiently, sealed again, this time in its entirety.

We installed IKO Cambridge 30 AR shingles on three of our apartment buildings this summer. We used the IKO because our roofing contractor recommended them. We recently read your column and you would not recommend the IKO 30. What should we expect of the shingles we installed this year, and what shingle should we consider for the remaining 17 buildings?

A. You have read of my personal experience with IKO shingles that were installed 12 to 14 years ago and have failed miserably in half or less than half of their warranty life. I cannot guess at what the life expectancy of IKO shingles installed now will be. I do not know if their manufacturing process has changed. I only know that they have refused to make good in one case that I am very familiar with and several others from readers who have e-mailed me. I have just had BP shingles installed on our house. I understand that they have not suffered from premature failure.

• 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 e-mail at henridemarne@gmavt.net.

© 2009, United Feature Syndicate Inc.