...........The Cajun Contractor
Home Improvement Broadcasting Network
Excellence In Home Improvement Information
Call Toll Free
Michael King’s. . .
Top Ten Dumbest Things To Do in the South
This is a no-brainer. Negative air pressures in buildings in hot, humid climates induce infiltration of hot, humid air. Period. Leaky ducts in vented attics and vented crawl spaces lead to negative air pressures.
You can never clean them. When they are wet and
dirty they grow bad stuff. They get wet and dirty. When they are wet
and dirty and when they grow bad stuff the only thing you can do is
throw them out. At least you can clean and decontaminate the metal
This is a vapor barrier on the wrong side of the wall. It should be put on the outside of buildings, not on the inside in the South.
If a carpet is dry, at the same temperature as the occupied space, and cleaned it is great. Especially if it has a vapor permeable backing. Now, it allows the concrete floor slab to "breathe" into the occupied space (vinyl floor coverings don't breathe, just like vinyl wall coverings). I like carpets that are dry, have no (or a "very small") temperature gradient across them and are cleaned. In schools which are slab on grade, forget it. The carpet is regularly colder than the air, especially when the a/c is turned off and you get the thermal lag. Now you have a higher relative humidity in the carpet than in the air. Now you get mold and dust mites. When was the last time you saw a school with a decent housekeeping budget? They can't afford to pay the teachers! Of course there is always money to pay the 16 levels of administrators. Then carpet is maintained and in a building which is operated correctly (HVAC system-wise), it is one of the best floor coverings around. But, if you aren't going to use carpet properly, you are better off not using it at all.
These systems are a disaster when they are applied over metal studs and gypsum or wood sheathing. They don't work because the do not have a drainage plane. For those of you who remember traditional stucco, the drainage plane was the building paper or tar paper installed shingle fashion over the exterior sheathing and under the metal lath. Traditional stucco always leaked rainwater. The function of the building paper or tar paper was to drain this leaking rainwater to the exterior. Brick leaks, wood siding leaks, vinyl siding leaks, etc. That is why all of these exterior claddings have building paper behind them to drain this water back to the exterior. These type of systems are called "forgiving" or water managed. Synthetic stucco systems typically do not have a drainage plane and therefore are a disaster.
I love brick. I also hate brick. Let me tell you when I hate it. I hate it when it does not have a drainage plane behind it that is also an exterior vapor barrier. Wet brick exposed to the sun is like a moisture capacitor which discharges to the cold side. The cold side is the interior air conditioned space. I love brick when there is a vapor barrier acting as a drainage plane between the brick and the rest of the wall assembly. Most brick in the South is installed without functioning drainage planes and effective vapor barriers. If you are not going to use it right don't use it. When it is used right, it is the best exterior cladding system around (just don't paint it).
They can't handle part load conditions. Most
systems that use them are inherently destined to be negative pressure
systems (meaning the building conditioned space operates negative). I
like them when they only do cooling and supply no outside r.
Dilution is not the solution to indoor pollution in the south. A bunch of cowardly Yankees refused to target the real issue of source control in many buildings due to the related issue of material off-gassing. Too many manufacturers of building products would get pissed off. What? You want me to actually tell you what I put in my product? And then tell me I can't put it in? No way! Hey, why don't we increase air change and flush out the nasties? Everyone wins! You get to sell more energy. You get to sell more and bigger equipment. Every existing system is now obsolete and now you have to make it bigger. Engineers get to charge more. Contractors really win. And you can continue to put the bad stuff in the products and sell them. Of course, no true Southerners were in that meeting. In the South there is more bad stuff in the outside air than there is bad stuff in the inside air. It's the charm of the South.
© 2006 Home Talk USA.