Thursday, January 19, 2017

American vernacular

Some years ago in college I had a nosebleed. Ended up in the small town ER where they shoved adrenaline up my nose and hooked me up to an IV to replenish my precious bodily fluids.

Kansas winters are no place for tropical island people such as myself. A room at 70 degrees when it's below freezing outside is easily drier than a desert. A humidifier solves this, but as anyone familiar with North American construction knows, you have to keep indoor relative humidity (RH) under 50% or else invite mold, rot, mildew, and who knows what else.

Outdoors, almost all places with a good climate have outdoor RH above 50% minimum. Most American homes don't just start rotting and molding over during the summer when temperature and humidity are high, so why is a humidifier a problem during the winter? Condensation.

Warm humid indoor air at 70F and 50% RH will condense on cold surfaces like windows; things like drywall and wood will absorb moisture. The current trend is to use complicated wall assemblies with sheathing, cavities, heavy insulation, vapor barriers, taping, etc. to ensure warm moist air doesn't contact cold surfaces.

It's a bit like the performance outdoor apparel industry where you are meant to wear a baselayer, insulating layer, wind resistant layer coated with a durable water repellent finish and taped seams. Theoretically it sounds optimal but then the durable water repellent finish wears off or simply gets soaked, the base layer stops wicking and all that fancy moisture and thermal management fluff you read on the card attached to the garment you bought at REI disappears.

In homes, insulation doesn't get applied properly, tape eventually stops holding, OSB delaminates, and moisture becomes a real problem as the organic material in drywall, frames, and sheathing, gets eaten away and all the plasticizers and stabilizers holding it together end up in the environment. Or in your lungs. So despite all the fine chemistry DuPont has embalmed our stick homes in, we still can't crank the humidifier to match an ideal climate.

Maybe two by fours and drywall made economic sense when lumber was cheap and high quality, but that's not the case anymore. Stick construction and the industry that supports it is a huge waste that reflect, as I suspect the American trade deficit also reflects, a generally high time preference culture.

High time preference means building roofs out of asphalt shingles that require replacing every 20 years instead of building a smaller house with a metal or slate roof that will last hundreds. My father's first impression of American homes was that "they looked good but then your realize you can punch through the sheetrock and it seems lousy". Middle class Filipinos as well as developing countries everywhere use reinforced concrete blocks. The engineering and quality are no doubt worse than American concrete construction (commonly used in commercial settings) but I have little doubt as to which material will stand the test of time.

There are tons of concrete buildings still around from Roman times and plenty of stone ones around the world. Not so much with wooden buildings.* So it's not like the technology doesn't exist to build long lasting low maintenance homes that can actually accommodate 50%+ indoor RH and are impervious to mold, insects, fire, flood damage, and whatever else concrete/stone has going for it.

But when you talk to contractors, most are used to doing things a certain way. "It's just not done here" Rather they talk about high performance within the context of wood stick construction which, even at its best, is mediocre in comparison. The way the industry markets its latest housewrap or pressure treatment though, you'd think disruption was a constant. It's an illusion.

* Maybe Shakespeare's Globe Theatre (if that didn't burn down) and there's this one Japanese temple made of wood that gets rebuilt every so often.