Job-Site Danger

Your article about the death of worker Lorenzo Pavia and the homicide conviction of contractor Kenneth Formic (In the News, 4/07) affected me profoundly. I talked about it with my fellow crew members on the job site. We spoke of the dangers we face daily and how our safety is dependent on the whims of employers struggling to make a profit and meet a deadline in a competitive business.

I'm a 60-year-old carpenter; I've had my share of accidents. My life is a series of calculated risks: questionable planks, ladders set on uneven muddy ground, frayed extension cords, slippery roof slopes, and, yes, deep trenches.

With the downturn in the housing industry, more workers will be vying for fewer jobs. As business becomes more competitive, men and women will do whatever it takes to keep a job. The young, the foolish, and the hungry will ignore these dangers, and unfortunately, contractors often view taking the time to set up properly as money out of pocket.

Sandy Ray Chapin

Mountain Grove, Mo.

Slap on the Wrist

Sixteen Saturdays and 16 Sundays in jail plus $5,000 equals one dead worker plus one injured co-worker? How fortunate for the perpetrator and his slapped wrist that he had our enlightened plea-bargain rules at his disposal. Look no further than this case if you think redress by civil action is "frivolous."

Ron Kardon, Architect

San Francisco

Problems With Spray Foam in Cathedral Ceilings

Regarding the article "Insulating Unvented Attics With Spray Foam" (3/07): I am a retired professional engineer who has inspected more than 1,500 homes in southeast Alaska. During those inspections, I found three houses that had from 2 1/2 inches to 4 1/2 inches of spray foam applied to the bottom of the roof sheathing, as described in the article. The houses were built between 1972 and 1977. The roof sheathing was 5/8-inch CDX plywood. Between 30 percent and 50 percent of the roof sheathing was rotted because of small air leaks in the spray foam. Most of these leaks seemed to be associated with the spray foam partially curing before a rafter bay was completely sprayed. The owners struggled for years with what they thought were roof leaks but was actually condensation from the air leaks in the foam.

Indeed, such moisture accumulation is more likely to occur in a wet maritime climate like Alaska's, where there is no hot, dry summer weather to dry out the roof sheathing. The problem is that builders nationwide are using OSB instead of plywood for roof sheathing, and OSB is much less forgiving of moisture presence.

It isn't that spray foam couldn't work; the concern is that it must be perfectly applied. A vented attic is very forgiving even of fairly gross errors in workmanship. The beauty of most of our currently used house building methods is that we don't have to be perfect — we only need to be reasonably correct.

John Bowman, PE

Tomahawk, Wis.

Author James Morshead responds: From your description, I can't tell exactly what material was used and why it failed. It could have been because the chemical ratio was off or because the foam was sprayed at the wrong temperature or onto a substrate that was wet or too cold. The foam used might have been a foam meant for roofing, a low-density foam, or one of the older formulations discontinued 30 years ago. For example, one type used in Alaska before being discontinued in the late '70s was a nonpolyurethane foam that was difficult to mix properly and contained urea formaldehyde. While the failure is unfortunate and could happen today, it isn't likely given the better equipment, the new types of polyurethane foam being used, and the improved training in the spray-foam industry. Many materials can fail when installed improperly, but it's unreasonable to suggest that because you can point to a few failures in an extreme climate, unvented systems don't work. There are thousands of new and older installations working well in far-northern climates, including Alaska. Even the current spray foams can fail if they aren't applied correctly. Like many high-performance or energy-saving methods, this is not an idiot-proof system. And yes, there is a trade-off between energy savings and a simple build-by-numbers approach. But if we are serious about energy conservation, then construction is only going to get more complicated. The days may be gone for good when we build the simplest way possible just so no one can make a mistake.

Use Stainless With ACQ

Regarding Merritt Kline's recommendation to use hot-dipped galvanized fasteners for permanent wood foundations (Q&A, 4/07), I would like to add that in the ASTM specification, that is the minimum standard. It's best to use stainless steel fasteners, which do not corrode at all when they are used with ACQ-treated products.

From field observations, it's known that hot-dipped galvanized fasteners in 20-year-old CCA-treated wood structures show signs of corrosion and failure. It's also known that ACQ — especially .60 ACQ — is significantly more corrosive than CCA.

Time will tell how corrosive ACQ is, but if I built the house, I would want to avoid potential liability by using stainless steel fasteners.

Mike Smith

Anna, Ill.

Chain-Saw Gang-Cut Plate

Where I can get a chain-saw guide plate like the one in the article "Getting Organized for Fast Framing" (4/07)?

Emery Boehs

Leland, Mich.

Commercially made models are available from Prazi (800/262-0211, www.praziusa.com/beamcutter.html) and Big Foot (888/798-4499, www.bigfoottools.com/headcutter.html). — The Editors