Finding cause of ice dams is critical for protecting house

Q. I need help with my icicles. My home is a frame ranch built in the 1950s. I have a one-car, unheated, attached garage. I have huge, some 3-foot-long, icicles around my entire house, including the garage. The attic had insulation blown in when I moved in 10 years ago.

I found many causes for icicles on the Internet with the bottom line indicating that heat is getting into the attic. Among the reasons are no insulation, heat transfer from ceiling drywall, from attic fans, etc. I have no recessed can lights, but I do have a pull-down attic stairway where I added some foam strips around the door. Maybe it wasn't enough?

I have hot water baseboard heat. Could heat be going up the wall where the baseboard heaters are and also through the ceiling in the semi-enclosed closet where the boiler is?

What I can't understand is why I also have huge icicles from the garage roof, which, again, is not heated and very cold. Any suggestions for what I might do?

A. Such large icicles are indeed a sign of a warm attic causing the snow pack to melt from the bottom. As the meltwater reaches cold eaves, it freezes - and icicles form.

Heat loss from the living spaces into the attic can occur through many avenues, but in your case, it seems that the attic's pull-down stairway is the main culprit. It is not enough to weatherstrip the perimeter of the opening. You need to insulate it, and this can be done in several ways. You can buy insulated covers online or in big-box stores such as Home Depot, or you can have one built. Google: "Insulated attic stairs covers" and you will find many choices.

It is common in ranches built in the '50s to have the main attic and the garage attic open to each other. It is not only a fire hazard, but also why you have such huge icicles at the eaves of an unheated garage. You should have a fire-rated partition built to isolate the two attics from each other.

It is also important to check for other paths that allow warm air to convect into the attic: separation in drywall tape, electrical switches and receptacles (you can buy closed-cell gaskets to install under their covers), etc.

An energy audit may point out all these paths and save you energy once they are taken care of.

Q. I would appreciate receiving your thoughts on comments I have concerning the following item in a recent column. It concerns the "duct mystery." Because the fan is axial, I wonder if the yellowish coloration could be caused by moisture collecting on a rusted galvanized reducing joint and running down onto the fan and the surrounding ceiling and wall (some oxides of iron are yellow). Galvanized steel does not last forever, and in 20 to 30 years it could be rusted through, especially in a humid/moist environment. Also, could the "stuff" clinging to the transition piece be voluminous rust?

A: Your comment is in reference to the following question from another reader: "However, in the summer of 2014, we began seeing a faint yellowish discoloration of the grid covering the fan inlet. Later on we began seeing the same discoloration, faint at first, but becoming brighter yellow, on the ceiling and walls surrounding the fan and extending to the floor of the bathroom. Today, using a mirror and flashlight, I examined the ductwork and found something clinging to the inside wall of the plastic pipe and the transition piece."

Another reader made the following comment: "It might be a mold or fungus. The 'something clinging' might be 'fruiting bodies.' Perhaps a friendly consultation with the questioner's local university biology department could help clarify."

Thank you both. I always appreciate any help I can get from readers who have either experienced and solved problems or have good suggestions to offer, which often provide helpful solutions.

Q. In a recent column you suggested laying plastic over sand in a crawl space and sealing up the vents to prevent mold. My crawl space is cement with a sump pump. Around the perimeter there are rocks covering perforated pipes that lead to the sump pump to help eliminate water penetration. My question is: Do I need to cover the air vents to the outside or should they be left open? Currently, I keep them open in the summer and closed in the winter, since there are water pipes running through the crawl space to the house.

A. You seem to have a perfect setup, but crawl space vents should be closed year-round. In the summer, they admit hot, humid air, which is undesirable.

Q. When we built our house in Shelburne, Vermont, 9½ years ago, we had bamboo flooring put in the kitchen. Over the years some nicks and scratches have occurred, and they now are black. I am wondering if the steamer that my wife bought to clean the floor has in some way created the black color in the nicks and scratches. I know you are not a fan of water on wood floors. We have ceased using the steamer after reading your column.

If the blackness was created by the steam-cleaning (or something else), what can be used to try to clean out the black color that won't harm the bamboo?

A. The wood flooring industry does not recommend using water or steam to clean wood floors. A damp cloth is OK to remove spills, but leave no remaining water on the floor.

The best way to clean wood floors is with Bona hardwood floor cleaner.

You may try removing the black marks with full-strength bleach applied with a small brush to the blackened areas.

Q. Our home is 2 years old and we are having ice damming problems. They are occurring over the front porch and on the side of an unheated garage. Both of these gutters are frozen solid to the top.

I don't think they are hung properly, and I won't know until I check them when the weather breaks. If they aren't pitched correctly, I'll fix it myself.

My question is do you think or know if a Gutter Helmet or a Leaf Guard system would help alleviate ice damming, or is a correctly installed gutter sufficient?

A. Ice dams form when the attic or cathedral ceiling is kept above freezing because of heat loss from the living space. The snow cap on the roof is melting from the bottom, and the melted snow runs down the roof until it reaches a cold surface. It freezes, and more snowmelt backs up behind the growing ice dam. The water may eventually leak inside the house.

The solution is to find out what is causing the roof to be above freezing; the best way to do this is to have an energy audit.

No gutter cover is going to fix this.

Q. My husband and I recently bought a home, and the driveway is sloped downward and has no drainage at the end. We are in desperate need of a new driveway as it's pitted, cracking and bumpy. We are unsure of how to proceed. Estimates are warranted, yes, but we want to make sure we don't get taken for a ride. Please see attached pictures. Thank you.

A. If the land slopes downward on the free side of the garage, the grade may be altered to allow drainage down that side. The new driveway will need to be poured with a swale before the garage door to direct the water away from the garage.

If this is not possible, you should consider a drainage trench with a cast iron cover across the entire width of the garage opening. Ideally, this trench should daylight in the backyard, but if this is not possible, it should be connected to a dry well sized to accommodate any expected downpour. Keep in mind that dry wells may eventually silt up, so there should be some way to have access to it to clean it out.

Check out several reputable asphalt contractors and get bids and references, and check their references.

Q. My question concerns insulation. I recently moved into the farmhouse built by my great-grandparents in the 1880s. It was constructed with no insulation in the exterior walls. During the energy crisis of the 1970s, my parents had foam insulation blown into the walls from the outside.

Since then, it appears the foam has deteriorated and crumbled, leaving the walls basically without insulation. I would like to have new insulation blown in, but am unsure which kind is best.

I looked online and saw that there are several types: fiberglass, cellulose, spray-in foam and soy-based foam. I understand the spray-in foam has the highest R-value, but is expensive and may contain harmful chemicals. However, living in western Pennsylvania, I would really like to use a product that will provide the best result. Which would you recommend?

The house is a two-story, wood-frame structure that still has the original clapboard siding. Another question: Since my parents had insulation blown in previously, the holes that were drilled into the siding by the installer are still there. Will it be possible to open and re-use those same holes for the new insulation?

A. I vote for closed-cell polyurethane, and, yes, you should be able to use the same holes.

Be sure you select a foaming contractor with a lot of experience in order to avoid the same problem your parents had.

• Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. His website is www.henridemarne.com. Email questions to henridemarne@gmavt.net.

© 2015, United Feature Syndicate Inc.