More Mold Mania Ahead
To the Editor:
The story "Mold Mania" (In the News, 1/03) is strange and disturbing. One item that the article failed to point out, however, was the underlying cause for the water damage in the claimant's home. Was it a construction defect, an accident, owner negligence, or something else? How the insurance industry responds to each of those causes may be legitimately different.
There are no licensing requirements for home builders or home designers in Texas. As a result, shoddy and inappropriate construction techniques have become the accepted norm here. For example, one standard residential construction uses brick veneer exterior walls on a concrete slab-on-grade. Usually, the exterior sheathing is OSB without any moisture resistant membrane. The flashing, if used at all, is typically 6-mil poly, installed haphazardly at best. I have never witnessed flashing being used at any lintel condition. I often see a poly vapor barrier used on the inside of exterior walls, even though that practice runs counter to the International Energy Code, which was adopted by the state in September 2001. Under the code, this region is considered a warm, humid climate. Because of the tighter construction required by the code, which drastically changes the rate of drying compared to the rate of wetting, I predict that Texas hasn't yet seen the worst of mold-related claims.
James J. White, AIA
Fort Worth, Texas
JLC senior editor Ted Cushman responds: The heart of the Ballard case was never about mold or construction defects. Although "toxic mold" (whatever that is) dominated the media coverage of the case, mold and health issues were not allowed in the courtroom. Construction defect liability never entered into it, either. It was a case about homeowner's insurance on an existing home that Ballard had purchased at a foreclosure auction, and the builder was never involved. The only part of the case that survived appeal is the part based on the insurance company's tardiness in assessing and paying the original water damage claim for Ballard's oak floor -- a technical violation of Texas business practices law. Ballard simply seized the opportunity to profit from a legal vulnerability that the insurance company had left itself open to. It's not clear from the record what the original water source was, but it seems to have been a leaking shower pan. If there's one lesson for contractors to learn, it's this: Water and moisture complaints should be addressed promptly -- not next week, not tomorrow, but today.
Old School Lives On
To the Editor:
I'm writing regarding the article "Metal Roofing Options" (1/03). In 1988, I installed Imperial Rib 38-inch-wide by 36-foot-long Galvalume roof panels on my own home. At the time, I explained to a company engineer that, given the length of the panels and the different rates of expansion of wood and steel, it would actually be better to screw through the 3/4-inch-high ridge rather than in the pan. This would allow room for the screw to "lean" back and forth during temperature changes, putting less stress on the screw, preventing the circumference of the hole from enlarging, and avoiding distortion of the whole panel, for that matter. That, plus a local farmer's advice that a hole in a ridge rarely leaks, while a hole in the pan is a sure leak, put me squarely in the old school. The engineer said, "Gee, I never thought of that," and off I went.
Twelve years later, I found a small drip in a heavy rain while inspecting the attic. On closer inspection, I found many screws backed out on the south-facing roof panels, probably because I hadn't used long enough screws. Still, only one leak!
So I got out the climbing gear and replaced all those backed-out screws with longer ones. And by the way, there was no elongation of holes, either. So I'm still firmly back in the old school on exposed-fasteners metal roofing.
Incidentally, screwing through the ridge is much more forgiving if your screw is off at an angle a bit, since, as I've pointed out, holes in the ridge rarely leak anyway. Just look up from under a barn roof that has roofing recycled from another barn; even with all those holes, there's hardly a leak in a hard rain.
Your Tax Dollars at Work
To the Editor:
I read with interest your article "Trouble-Free Foundations for Expansive Soils" (11/02). I'd like to tell your readers that the Engineering Properties and Universal Classifications of Soils is available free to virtually all U.S. citizens. Visit your county U.S.D.A. Natural Resources Conservation Service office, which has mapped all soils in the U.S. and has published a soil survey for each county. Find your land via legal descriptions or just look at the aerial photos in the book, then check the keys for your soil type. The appendix has a chart with the engineering characteristics for each soil in that county.
It still pays to double-check the soils for a particular site, but these soil surveys come pretty close to the mark. NRCS offices can be located in the phone book blue pages under U.S. Government, Agriculture subheading.
Oklahoma State University Cooperative Extension Service
Tulsa County, Okla.
Strength of Adhesive in Laminated Rafters
To the Editor:
The strength of the built-up rafters described in the article "Cutting Barrel-Vault Rafters" (12/02) depends to some extent on the bond of the "construction adhesive" used between the 2x12 core and the plywood joint scabs. Though the variety of adhesive was not identified, from the photo it appears to be the type that is not suitable for use where the joint is under continuous stress, because this kind of adhesive remains pliable after curing. Under long-term loading, such nonhardening adhesives tend to creep and may allow the glued parts to gradually slide out of position. If the strength of the adhesive was relied upon by the engineer, it would be important to select a hardening adhesive rated for continuous loading in a critical application such as this.
Carl Mezoff, P.E.
Author Mark Lord responds: The engineer who designed the rafters specified "standard construction adhesive," so we used the brand that we have had the best results with. Had we been using only adhesive to bond these materials together, it would clearly have been of paramount importance to use the correct structural adhesive, as Mr. Mezoff points out. However, the engineer's design called for a rigorous schedule of clinched 16-penny nails to do the structural work. The construction adhesive was very useful for holding the laminated layers in alignment as we worked.
Another Crown Jig
To the Editor:
The gauge I use places the molding perfectly and shows where compromise is necessary. Using the jig, I can also hold the molding with one hand while nailing it with the other hand. I generally make the gauge out of 1/2-inch plywood and cut it at least 12 inches long. You simply cradle the molding in the jig as you press it to the wall; you don't need to make any marks on the wall.
As I measure the length for each piece, I start by striking a "bash block" at each inside corner of the room to make sure the drywall is tight to the framing and that there is framing there to support the pressure.
Collins Trim and Remodel
To the Editor:
Joe Stoddard's article on digital cameras (Computers, 1/03) doesn't mention floppy-disk storage cameras like the Sony Mavicas. Sure, floppies are "old" technology, but they're cheap, you can get them anywhere, and the pictures can be read without a special program. There are tons of cameras out there, all the way up to and higher than the Nikon D100 my photographer wife uses, but I'd vote for the Mavicas as being highly friendly technology in comparison to others.
Joe Stoddard responds: I had originally included a section on Mavicas but dropped it when I edited the article for length. The upside of Mavicas is that the files are easy to share; real estate salespeople love them because it's so easy to hand off the images. On the downside, the 1.44-MB image isn't that great, plus the cameras are big, bulky, and relatively expensive. A source at Sony also recently told me that floppy-disk models are not long for this world; Sony plans to move everything to CD-R.