Is "Wiring for the Future" Really Needed?
Many things have amused me over the years in the field of home construction, but none more than so-called high-tech wiring (see "Wiring the High-Tech House," 5/05). This makes about as much sense as those craftsmen who built ornate outhouses in the 1920s. The trend today is clearly toward wireless. We already have wireless phones, speakers, keyboards, and routers. It's clear that the house of the future will have far less wire than we have today. I can imagine how workmen in the future will react when remodeling today's home to find the partitions crammed full of unused wires.
Sayre, Pa.
Author Helen Heneveld responds: It might amuse you, but I can tell you from experience that it's not amusing to the homeowner who tries to print a document using his wireless network, only to learn that the document is printing to the next-door neighbor's printer. Although your perception is quite common, it's actually a misconception: Wired networks are here to stay. Wireless technology certainly has its place, but as a complement to a hard-wired network. Builders interested in providing home networking for their clients should always install structured wiring as the foundation for the network. Dedicated wiring is more secure, faster, and less prone to signal interference. It's then a simple matter to add the convenience of wireless devices.
Painting Stucco: Questions & Answers
Although the article by Joe Lstiburek ("Why Stucco Walls Got Wet," 7/05) had lots of information that made sense, there are a few things I question.
I have found no evidence that painting stucco is a good idea, yet the author matter-of-factly addresses painting as a must-do. The only stucco houses I've seen that have no problems are the unpainted ones. The painted stucco homes I've seen show bulging problems over the years, ironically for the same reason the article points out — trapped moisture.
Furthermore, the author advises sealing cracks with caulking or a cementitious crack-repair formula. I daresay there is no caulk or cement that is watertight used in this application. Even if someone develops a product that does the job, you can't tell by looking at the repair if it is watertight or how long it will stay that way. Certainly after it is painted, you cannot tell. Following that advice is a recipe for destroying the stucco.
It's better to leave the cracks alone and not paint the stucco. Sure, the cracks will allow some moisture to penetrate the surface, but they will also allow a way for moisture to get out. Moisture-proofing should be done behind the stucco, as the article shows very well — not on the face of the stucco. That's true for all siding.
Les Deal
Cedar Rapids, Iowa
Author Joe Lstiburek responds: The vast majority of stucco installations in the U.S. are painted. Most stucco installations are found in hot-humid and hot-dry climates, not cold climates. However, even in cold climates, most stucco installations are painted — not always successfully, but they are typically painted. In cold climates, any coating that is hygrophobic and vapor-permeable is good for absorptive claddings, including stucco. Latex-based coatings that are at least 10 perms or more (as mentioned in the article) can also be effective for cold-climate applications. However, as you note, many stucco systems perform well in cold climates when left unpainted. These systems have to be "good" — that is, well-mixed, correctly applied, and properly cured. Aged, deteriorated stucco is a different story, and is typically a candidate for surface coating and surface consolidation systems. These systems have a long track record of successful performance if they are vapor-permeable. Older paint systems typically did not meet these breathability requirements, and so tended to trap moisture and blister. Thus "painting" stucco in cold climates has historically been fraught with problems. But this is not the case with the highly permeable coatings available today. As for crack repair, there are effective techniques and materials that can do the job — not perfectly, but effectively. In mass wall assemblies (that is, assemblies that do not have building-paper drainage layers), reducing entry through cracks is essential. In drained assemblies, the cracks are irrelevant and can be left open. They may be aesthetically unpleasing, but they do not constitute a performance problem. I remind readers that there are two types of walls common in Florida and both types of walls were discussed in the article: mass walls (stucco applied directly on block) and frame walls (stucco applied over building paper, wood sheathing, and framing). The frame walls should be designed to drain via secondary drainage behind the stucco as discussed in the article (see also my previous article, "Water-Managed Wall Systems," 3/03). In mass walls, the primary rainwater control is done on the surface of the stucco, as there is no other option. Leaving the cracks alone and not painting the stucco in mass walls has been shown to be ineffective, whereas fixing the cracks and painting the stucco has proven effective.
Are Membranes "Flashing"?
Someday, I hope, we can all collectively agree on how a window really needs to be installed. Carl Hagstrom's article ("Flashing a Flanged Window," 6/05) was JLC's latest attempt to make the process simple, but once again fell short. What happened to drip caps? Have the window manufacturers now gone back to the thought that nailing flanges make drip caps — also known as head flashing or Z-flashing — obsolete? Or are we to believe flashing membranes provide this function?
Section R703.8 of the International Residential Code says: "Approved corrosion-resistive flashing shall be provided in the exterior wall envelope in such a manner as to prevent entry of water into the wall cavity. ... The flashing shall extend to the surface of the exterior wall finish and shall be installed to prevent water from reentering the wall envelope. Approved … flashings shall be installed at … top of all exterior window and door openings in such a manner as to be leakproof."
I question whether the "flashing" in this article is really flashing or corrosion-resistive, whether it is extending to the surface of the exterior wall finish, and whether it is making that window opening leakproof. Is it really a sound idea to "flash" to the secondary water-resistive barrier rather than to the primary exterior wall finish?
The code does not think so and neither do I, but we have been relegated to these Rube Goldberg experiments by the window companies, which committed to a fundamental marketing error in developing these flanged albatrosses. The unfortunate result is that they are bound to this deception because to admit otherwise would be an admission that their products are defective.
Someday, some entrepreneur is going to get wise and make a plastic or metal window that actually does flash to the exterior. Until then, I guess we must be satisfied with JLC's latest valiant attempt on this controversial subject.
Steven Pedracine
Director, Minnesota Lath and Plaster Bureau St. Paul, Minn.
Author Carl Hagstrom responds: I think the issue of whether drip-cap flashing is needed depends on the configuration of the flange connection details on the window unit. I feel that the flange detailing on many of the windows I've installed performs the same function as a drip cap. I've seen window units with "open" corners, where the flanges aren't integral; these types of units would certainly benefit from a drip-cap flashing. Incorporating a drip-cap flashing detail is straightforward: You just place the drip cap on the window head after the jamb-flashing membrane has been installed. The next step — installing the self-healing head-flashing membrane — will cover the vertical flange of the drip cap, and since the head-flashing membrane adheres directly to the sheathing, it will intercept moisture that migrates down either the housewrap or the sheathing and direct it back out to the primary drainage plane (siding). Adding a drip cap to any window unit isn't a bad idea. It's also important to remember that as the wall height increases, the need for intermediate exit flashing details (weeps, for example) increases as well. If moisture gets behind the siding on a one-story structure, it doesn't have far to go before it exits at the drainage detail where the siding overlaps the foundation. In a multistory structure, relying on the housewrap to direct moisture to the foundation weep becomes much more of a gamble. Providing intermediate flashing details that direct moisture from the secondary drainage plane back out onto the siding is important. These details are common in multistory commercial construction, but are often overlooked in residential construction, and, in many cases, present aesthetic challenges. Hopefully, as residential builders become more aware of the importance of proper flashing details, they will add these intermediate exit flashings to their flashing bag of tricks.
