Q. I am a faithful reader of your column. I have learned so much from you -- enough to know that I need advice before we invest in a new roof for our Cape Cod-style house.
The house has two front dormers and one large dormer off the back of the house where the original owner added a bedroom upstairs. The roof on that dormer has been leaking around a vent pipe and has to be replaced. We are thinking about replacing the rest of the roof as well. When the main roof was installed 17 years ago, we bought the "upgraded" 35- to 40-year long-life shingles. We are not happy with the condition of these shingles. A contractor who replaced the siding on the rear dormer this spring said the roof was "cooking" and needed to be replaced. I am sure this is related to the heat problem on the second floor.
The house has a high-efficiency, two-stage air conditioner that is 10 years old. It cools the first floor fine, but the upstairs bedrooms are not cool at all. We have added two window air-conditioning units because it is too hot to sleep in the summer. The sloped roof in the upstairs bathroom feels warm to the touch. The front of the house takes direct sun all day. There are a few crawl spaces, but no true attic in the house.
We are wondering if the type of roof vent we have is the best for this situation. Should we add a fan in the front crawl space? Should we add more insulation? We would like to do whatever is appropriate to try to keep the upstairs cooler and keep the roof from cooking. If the vents should be changed or improved somehow, I will want the roof contractor to do so.
A. Thank you for sending photos. Unfortunately, those labeled as showing the leaky vent do not show the vent. I do see a plumbing vent on the right side above the covered deck, and it is installed incorrectly. The top and the sides of the boot should be covered with shingles, but the apron at its bottom must be over the shingles.
The large dormer roof looks quite shallow, and shingles may not be suitable for it; a synthetic rubber roof would be better. This could be done independently from the rest of the roof.
The photos are too small to show the "cooked" condition of the shingles. You may have read in my column over the years that there is a history of early shingle failure, so the fact that they are not in good shape after only 17 years is not surprising. But do not expect better results with new shingles. The industry is fraught with problems and has been the subject of many lawsuits.
The excessive heat on the second floor is probably due to poor insulation and a lack of adequate ventilation. If you can ascertain that the spaces between the shallow roof rafters of the large dormer are filled with insulation (without ventilation space), you may want to consider having 2-inch-thick rigid insulation applied over the sheathing, and 2-inch by 3-inch sleepers fastened over the rigid insulation to provide a vented space. The sleepers should extend 3 inches beyond the eaves so that a continuous metal vent strip can be installed on their bottoms. A ridge vent will complete the ventilation chutes. New sheathing and rubber roofing will complete the job with a slight alteration at the peak to accommodate the added thickness. The added insulation and newly created ventilation should help a lot in cooling the bedroom.
You haven't said what type of roof vent you have, but I see what looks like a ridge vent on some parts of the roof. If there are soffit vents in the eaves overhang, and if there is a continuous, unimpeded airspace between the soffit and the new full-length ridge vent, this should help.
If the ceilings of the steeper roof are hot, rigid insulation can be installed over the existing ceiling finishes and new drywall put up. I am not in favor of attic fans.
Q. Your column has provided very helpful information; please keep up the good work! Now I need your advice. I have a patio that is between our house and garage. Over the years, due to the cold and snow, cracks have developed. I finally seem to have licked the cracking problem, since none have developed in a while. (I used a combination of silicone-based caulk and a self-leveling caulk.)
Rainwater now accumulates in the center of the patio where the biggest repaired crack is. The water accumulates to between one-eighth inch and one-quarter inch (see photos). How can I prevent water from accumulating on the patio? I thought of using self-leveling cement, but I'm not sure what type.
A. Hose off the wet spot to remove all loose material. Let it dry and apply one of the patching cement mixes on the market, following the directions on the package. Thorocrete, Top 'N Bond and Quikrete are some of the products to use. You'll find them in hardware, building supply and big box stores.
Q. I don't know how many readers are women, but here's one granny who reads your column every week. Love it!
Last fall we had dead branches cleaned out of large oak trees around our home. In the process, the arborist told us that moss is growing on the north side of our roof -- that would be the highest part of the house. The house is 12 years old.
I have read in your column about using a vinegar solution to remove moss. Would this work on the roof? What is the ratio of vinegar to water?
Also, do you have a recommendation for keeping the moss from growing back? I have heard of using zinc oxide-coated step flashing. Where on the roof would this be applied, and how? I've spoken with two different roofers, and neither had heard of this. Any information would be most appreciated.
A. The formula is three parts white vinegar to one part water.
Zinc strips are effective in removing and preventing the growth of moss, lichen and algae from roofs. You may have seen old barns where the shingles below galvanized roof vents are sparkling clean, whereas other sections of the roof are stained. You can buy zinc strips, called Shingle Shields, from www.rainhandler.com. They are installed just below the cap shingles at the peak of the roof.
Q. I would like to know what I can use to remove many black spots on my home siding, wood and aluminum doors that appear to be caused by overheated mulch nearby. It seems that the mulch sends explosions of material onto any nearby surface that then require fingernail scraping or more effort to remove. I have tried the usual siding cleaners with a soft brush, with no results. I also tried sodium percarbonate by OxiClean with no results. There are too many spots to do them individually. Can you suggest a way to remove these ugly spots?
A. The ballpoint-size black dots on your vinyl siding and doors are artillery fungus, and they are coming from decomposing mulch next to the foundation. The fungus explodes in the spring or fall when the temperature is ideal, propelling the spores 20-plus feet in the air.
It is difficult to remove the fungus without seriously damaging the vinyl siding and any surface to which the fungus attaches itself. On wood siding, repair is possible, but not on vinyl, aluminum or steel.
Short of replacing the affected pieces, one answer is to paint the surfaces after a thorough cleaning, although the dots will still be there.
The only way to prevent this in the future is to put new organic mulch over the old every year, remove the old mulch entirely or replace it with rubber mulch, available in garden-supply stores.
Q. Can you cover a flaw in a granite countertop with clear epoxy and wet sand to match the sheen of the countertop?
A. What type of flaw? If you know where the counter was bought and its manufacturer, call the dealer and discuss the problem with them. Either a photo of the flaw or an inspection visit by one of the dealer's representatives should elicit a suggestion for repair, if it is possible.
Q. My home, a two-story with attached garage, was built in 1998. For added space, we had the builder excavate under the garage and finished the area with walls and a drop ceiling.
My problem is this: The garage floor has developed small cracks (nothing major, but large enough to see). Water and road salt from our wet, snow-covered vehicles have found their way through these cracks and the concrete flooring and are rusting out the metal sheeting that the concrete was originally poured onto. In some areas, small pieces have been eaten away from the metal completely, and occasionally a staining, rust-colored drip finds its way through the channels in the drop ceiling and onto the carpet. I know the metal pans don't provide strength to the garage floor, but is this a bigger problem than I am giving it credit to be?
I would like to have my garage floor coated with an epoxy such as UCoat It, or even have a company come in and do it professionally to make it look nicer. Do you think this would fix the cracks and stop the water from rusting more of the metal panels, or would the cracks reappear?
I have attached a couple of photos. There are two that show the small cracks that have formed on the garage floor. The others are the metal panels from underneath.
A. You should make sure that the metal pans are not structural, as they are in danger of failing. A concrete contractor or structural engineer can detect any metal re-rods in the concrete to make sure that the concrete is reinforced and that the pans were used only as forms for the pouring.
The salt that has been oozing through the cracks in the concrete floor is also affecting the metal re-rods and causing them to rust.
This can present a long-range problem, which either of these professionals can address. They will also suggest a coating to seal the floor.
Q. My wife and I recently purchased a 1960 ranch-style home. It has an enclosed, three-season room with a concrete floor. Previous occupants kept one or more cats in this room, and the urine seems to have seeped into the concrete. Unfortunately, before this could be addressed, the owner painted the floor with an acrylic paint. The odor remains.
What can be done to remedy this? Can the concrete be cleaned or treated, or can we apply some type of coating over it?
A. It will be difficult to get rid of the odor now that the concrete has been painted, but you can try washing the floor with Nok-Out (nokout.com). The odor also may have permeated the walls, so you could spray Nok-Out on them after trying it first on a small, inconspicuous area to make sure it will not damage the finish.
If that does not work, you may have to remove the paint and treat the raw concrete with Nok-Out before repainting it.
• 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 firstname.lastname@example.org. His book, "About the House," is available at upperaccess.com and in bookstores.
© 2012, United Feature Syndicate Inc.