Keep Bath Vents Away From Soffits
To the Editor:
I am currently involved with a whole-house rehab on a ten-year-old ranch house. The bathroom vent fan exhausted to the outside near the soffit vent strip. Inside the attic, the roof sheathing was nearly completely black with mold from the soffit (in the truss bay directly above the exhaust) all the way to the ridge vent, with the mold fanning out in a V pattern about 6 to 8 feet wide at the top.
While I did not find it necessary to "fit my cap with a chin strap" while working near the soffit vent, as Arne Waldstein wondered (Letters, 2/04), it might have been helpful to keep my jaw from dropping so far when I reviewed the proposed remediation cost of $6,488. (The attic did have some other minor areas of mold, as well.)
It may not be common sense, but I'll be locating vents away from soffits!
Jim Conneman
Conneman & Associates, Inc.
Barre, Vt.
Top-Down Roofing
To the Editor:
The article about top-down roofing by Mike Guertin (1/04) was interesting. However, Mr. Guertin states, "A roofing nailer helps, since you don't have to lift the shingle very high in order to sneak the nailer nose in place."
If you are not lifting the shingle very high, I assume that the nail is not being driven into the shingle at a 90-degree angle. Therefore the nail head is not flat on the shingle, and the shingle is possibly cut where the nail head is at an angle. This can cause premature shingle failure from high winds.
Ken Kammerer
Building Official
Redwood Falls, Minn.
Mike Guertin responds: I'm in complete agreement with you regarding the proper way to nail asphalt roof shingles. I can see how my phrasing in the article could cause concern. Nails must be driven perpendicular to the roof surface so that the nail heads lie flat, not only for the wind resistance you note but also to prevent raised edges of nail heads, which can damage the underside of overlying shingles.
Here's how I position the nailer (see photo, above). Since nails are positioned about 5/8 inch above the butt edge of overlying shingles, I only have to gently bend up the exposed portion of the shingles above the row I'm nailing. This avoids putting stress on the line of nails holding those shingles down. To squarely position the nose of the nailer, I need only lift the butt edge about 2 to 3 inches. By contrast, hand nailing would require the top shingle to be curled back in order for the hammer swing to clear.
Saw Is a Winner, but...
To the Editor:
I couldn't agree with Tim Uhler more ("Tool Test: Wormdrive Saws," 2/04). The DeWalt saw that he and his crew agree to be their favorite is definitely a winner. I've only had the opportunity to use the Skil HD 77 and the Skil Mag 77 while framing and running exterior trim. Both saws are bulletproof, but heavy.
The first time I saw the DeWalt saw, I liked it immediately. For two years the saw seemed perfect, then it was downhill from there. Unlike the Skil saws, DeWalt made no provisions to add to or change the gear lube in the hypoid gears. Thus, as the factory-installed gear lube dried up, the gears proceeded to shred themselves. The only way to change the lube was to completely disassemble the saw or send it to a service shop, which meant downtime.
DeWalt has made a winner of a saw, but they need to make it a proven champion by redesigning it so that carpenters can add or completely change the gear lube! I went through two of these saws in two years. I haven't bought one since, but if DeWalt changes the design, I'm sure the price will continue to be appealing to all who love this saw.
Kevin Jewell
Anderson, Ind.
APA Recommends Building Paper
To the Editor:
In his article "Fixing the Holes Where the Air Gets In" (1/04), Mr. Torrey is right in believing that very little air moves through the wood structural panels (plywood or OSB). He therefore recommends using only sealing tape on the horizontal joints, rather than the usual housewrap. For air infiltration alone, which is the subject of the article, the tape alone probably works.
Unfortunately, the article makes no mention of protecting against water intrusion — plain old leaks — which can lead to mold and structural decay if prolonged. Weather resistant barriers such as housewrap or building paper create a drainage plane to help protect against moisture damage within the wall.
This concern over leaks through siding joints and around doors and windows led the International Building Code and International Residential Code to require paper behind all exterior sidings. APA also recommends it as inexpensive insurance against potentially damaging water leaks.
Fulton Desler
APAThe Engineered Wood Association
Tacoma, Wash.
Likes ASHRAE 62.2
To the Editor:
As usual, the January issue of JLC has excellent coverage of building science issues. Your consistent inclusion of balanced, results-oriented, and science-based content on moisture, air quality, energy, combustion, and hvac issues is the main reason I subscribe to JLC. But I was disappointed by the news piece about the new ASHRAE ventilation standard 62.2 (In the News, 1/04). While you cover the basic facts and history accurately, it seemed to me strangely biased toward the reactionary, suspicious stance of NAHB and GAMA regarding the standard.
Just because there are no established residential exposure limits for most indoor pollutants, does that mean we should do nothing? Why do we have ventilation standards in commercial and office buildings and yet none for homes, when home is where many of us — especially our children — spend more hours than any other single place? It is largely because of the building industry's reluctance to accept the benefits of mechanical fresh air ventilation. Years ago I taught people about ventilation almost as an apology, as a strategy to employ when you build a house tightly on purpose. But a lot of homes get built "too tight" by accident, and I've seen plenty of leaky homes with mold or other air quality problems that ventilation has helped solve.
A simple, inexpensive ventilation system — at a minimum — is a good idea in every house. Once installed, you don't have to worry about "too tight," and many callbacks can be solved quickly over the phone. Ventilation doesn't fix everything, but it's cheap insurance. Let's not be afraid of this becoming established practice in the residential building industry.
Bruce Harley
Conservation Services Group
Westboro, Mass.
