Q: The soffits on the addition to our house rot out after only a few years. The soffits themselves are not vented, but there is a large gable vent. There are identical gable vents on the main part of the house. The soffits on that portion of the house are not vented, yet they are still in great shape after nearly 30 years. Since the roof of the addition meets the side wall of the house, could the problem be that the soffits trap condensation because the gable vent does not have a free outlet at both ends? When we install new soffits this summer, should we have vent holes in them?
A: Yes. The new soffits should be vented. Although I do feel that the attic is not properly ventilated, I suspect that moisture is also being introduced into the attic from interior sources. A typical source of interior moisture is a bathroom exhaust fan that discharges into the attic rather than outside.
On the exterior, check the roof to be sure that damaged shingles aren't allowing moisture to penetrate and that there are no open joints in chimney flashing, or around vent stacks or skylights.
Once these checks are complete, remove the soffit and push any insulation away from the eaves to ensure that the vents won't be blocked. Install polystyrene baffles in the attic above the soffits to ensure that airflow through the soffit vents won't be obstructed.
Next, make new soffits with vent cutouts. It's important to prime the interior and exterior soffit surfaces, the endgrain and all cut surfaces before installing the soffits. This is known as backpriming. Apply a coat of exterior paint to the soffits, install the vents, then install the soffits. At some point, you will need to reroof the addition. When you do, install a ridge vent to improve airflow.
Several do-it-yourselfers read our recent piece on fastener extraction and wrote to say, "Hey, what about Spin-It-Out bits?" Good point. These useful bits are made by Eazypower (eazypower.com). They have a 1/4-in. hex shank that fits nicely into a drill or a multibit screwdriver. At the tip, the bits have aggressive serrated edges that dig into stripped-out screw slots, mangled fastener heads or even a broken piece of screw shank. They also work on paint-covered screws.
Roy Bellon, Oak Park, CA: Roy Bellon has been reading POPULAR MECHANICS for 40 years and servicing air-conditioning equipment for 30. So he seems well qualified to write on this topic. After reading our advice on cleaning ducts, he wrote to tell us of a likely cause of dirty air-conditioning vents. Rather than dirty ducts, the real culprit is dirt in the room's airstream, he says. A vortex forms in the air as it discharges through the vent. This imparts a static charge to the grille. The charge causes dirt in the room's air to stick to the grille. His advice: Use high-efficiency air filters in the air-conditioning system and clean the vent cover with detergent and hot water.
Q: I found PM's recent tip on using foam sealants to fix a loose shower head very interesting. I use Dow Great Stuff a lot, and I really like the product. How do I find an MSDS for it?
A: An MSDS, or Material Safety Data Sheet, must be provided by a manufacturer for any product that contains chemicals deemed to be hazardous by the Occupational Safety and Health Administration. The things it may list are the product's chemical composition, the dangers posed by those chemicals if ignited or spilled, and first-aid and fire-suppression measures. The MSDS for Dow Great Stuff Big Gap Filler, for example, states that the product emits dense smoke when it burns, and notes that corn oil is more effective than soap and water for removing it from skin.
To get the MSDS for this product, go to the Construction/Professionals section of greatstuff.dow.com.
When a company does not post an MSDS on its Web site, contact its technical service department.
Q: A branch fell onto my shed and put a big dent in the roof. How can I repair the roof without ripping off all its shingles?
A: Whether you strip all the shingles off the roof depends on their general condition. If the dent is small, and if the shingles other than the damaged ones are in good condition, then replace only those shingles necessary to fix the roof deck.
Aside from replacing the shingles, you will need to make structural repairs to the shed's rafters or to its roof deck. If the falling tree branch cracked a rafter, attach a piece of framing lumber to it using 12d common nails in a staggered pattern. Space the nails about 12 in. apart. The lumber should be as wide as the rafter and long enough to span the damaged area plus 2 to 3 ft. on either side of it. To replace a damaged section of roof deck, cut out the damaged section to the center of the nearest rafter or install blocking on the rafter's side that will allow you to fasten the repair piece of plywood.
Q: My home has a family room with a vaulted ceiling that runs to the ridgeline of the house. The room looks great, but it's hard to keep it heated and cooled to the same temperature as the rest of the house. What can I do?
A: The most common way to deal with this problem is to install a ceiling fan. In winter, for example, heated air rises toward the ceiling, and cool air settles toward the floor. Depending on the room size and shape, it's not unusual to find as much as a 15-degree difference between the floor and ceiling. The ceiling fan can be used both winter and summer to mix air layers with different temperatures, making the room more comfortable.
It seems counterintuitive, but the fan should force air down during the summer because the downward airflow cools a person as it moves over the skin. During the winter, the fan should produce an upward airflow to force the layer of heated air at the upper level to wash down the walls. This will raise the temperature in the occupied area of the room.
An easy way to determine whether the fan airflow is up or down is to look at the fan blades as they rotate. The blades are installed on a slight angle. If the blade's leading edge (the edge facing the direction of rotation) is up, the airflow is down. When the leading edge is down, the airflow is up.
If you have a ceiling fan and find that it's not effective, you may be able to achieve better air distribution by having a heating-cooling contractor install an inline fan in the ducts leading to the room.
Q: Can I adjust my Allister garage door opener? The door gets close to the floor, then goes back up.
A: The problem may be due to a pinched door track, an improperly adjusted remote control or a malfunctioning photo-sensing device. A garage door operated by a pre-1993 opener reverses downward travel if it encounters resistance. Doors with post-'93 openers reverse from resistance and have a second -safety device, the most common being a photo-sensing beam.
First, check the track. Disengage the opener, then operate the door by hand. If the door binds, adjust or replace the track. If the door moves freely, try adjusting its remote control. If you don't have an owner's manual that explains this, download one from allstarcorp.com. (Allstar owns the Allister brand.) Likewise, if the opener's photo sensor is out of alignment, check the manual.
Just ask Norman about it. Send your questions to Homeowners Clinic, Popular Mechanics, 810 Seventh Ave., New York, NY 10019 or pmhomeclinic@hearst.com. While letters cannot be answered individually, problems of general interest will be discussed in the column.
Pat Porzio III, a master plumber and electrical contractor, runs Porzio Heating & Cooling in Haskell, N.J.
Sometime in June we get our first desperate phone call from a homeowner: "Hi. I've turned on my central air conditioner for the first time this season, and it isn't working. How soon can you get here?" I can only reply: "Not as soon as I would like." By the second 90-degree day of the season, our phones will go nuts, and we will be inundated with a wave of service calls.
To avoid the crush and to reduce the burden on an a/c system that has sat idle for several months, I urge people to test their system as soon as the weather is in the 70s. Here are the basic steps that every homeowner should take at the onset of the cooling season.