OSB on the Roof
Bill Rose's article on roof ventilation ("Roof Ventilation Update," 10/07) was an excellent review of the factors that influence vapor accumulation in vented and unvented attics. At the APA/Engineered Wood Association, we have been testing, certifying, and studying the properties of OSB for over 25 years, so we do not share the concern that "we still know too little about the moisture performance of this material."
We know the structural, dimensional, and physical limitations of the product and provide installation guidance to ensure proper performance. We also know that, similar to other untreated wood products, OSB is subject to biological degradation absent proper design, installation, and maintenance of the structure.
An extensive source of technical and installation guidelines on the topic can be downloaded for free at www.apawood.org.
Steve Zylkowski
APA/Engineered Wood Association
Tacoma, Wash.
Drywall Butt Joints
Nice article ("Taming Butt Joints," 12/07) — but Greg DiBernardo didn't mention one shortcoming: The wheel on the ButtTaper is aluminum and picks up tiny crumbs of drywall that get stuck because of the pressure you apply. This makes for a bumpy ride after a while, and scraping the wheel clean many times a day with your fingernail is no fun.
For the price charged, I would expect a hard stainless wheel with a polished rim so the drywall crumbs don't stick to it. In fact, I'm having my local machine shop make me a stainless wheel.
By the way, for small patches you can do the bevels easier with a smooth, rounded tool; I use the top of my Channellocks.
Dorian Gluckman
Gluckman & Co.
Birmingham, Mich.
Author Greg DiBernardo responds: That problem has never been an issue for me. I assume anyone using setting compounds keeps a water bucket close by for cleaning tools and the like as work progresses; I just dunk the wheel in the water occasionally and everything slides right off.
Siding Solo
Because fiber-cement siding is so heavy, it's difficult when working alone to hold it to a line, match up a butt joint, and start the first nail or screw. Here's a simple solution:
I use two gauge blocks, one near each end, to provide stable, accurate support until two or three fasteners are in place (see illustration). If the siding needs to be tweaked a little, I just slide a shim in between the block and the bottom of the siding. Once the piece is fastened, I back out the screws in the coil stock and reset the blocks for the next course.
Roger Stenhoff
Spring Grove, Minn.
