Speaking of hot humid TX. When I went down and visited George Swanson author of Breathable Walls (great book) in Austin last year he told me of Passivhaus homes that were certified at .6 air changes per hour, a very tight air seal but were a 100% vapor breathable with fast drying rates. Baffling how Germany can get that rating that most can only with vapor barriers. Now a similar entity called PHIUS has started in Chicago but we can't get there with toxic materials so they got a divorce and are not trying to figure it out. The big issue ventilation rates that have no reference to sick homes as if the issue is being ignored.
Also baffling how many of the better natural building materials we discuss out here are never promoted by the "green" building scientist nor is there much proof, testing, or discussions on IAQ. Wonder why? No sponsors.
I was at a home show lately explaining IAQ and natural materials. The hemp was big draw. Many did know it is a great building material that absorbs
CO2 like a plant and gets harder and harder with as high of r-value and far better dynamic hygrothermal mass we have built with for centuries. I explained I am not doing anything new, just bringing back better materials and building practices along with tested and proven IAQ. I told people to go get another builder to provide a third party IAQ, if not call me
Many parts of the country have worse outdoor air quality than indoor. Many do not want to open windows or whole house fans due to allergies, farmers around here that stir up dust. Dusty winds are a big problem in dry desert climates like out west. I think we are moving to a condition air demand with HEPAs, MERVs, etc....
Air sealing makes sense only if done properly.
I was talking to our
local fire marshal at a local
city meeting late last week about hempcrete he referred to as a "alternate building material" since it is not in international or local codes. Why?
Politics and $$$$. I explained the burn rate of rock (limestone slag) and soil is better, lower than what we use today. Imagine that when does rock and soil burn?
Saves lives. He was very supportive but may want me to dig up some test info from centuries ago. I also explained I don't use combustible appliances or gas, or fossil fuels, to power my homes. More "alternative building methods" I guess
See that plastic bag of weed I mean hemp on the table I labeled it. Very entertaining!
To the right is a hemp casted cube with a lime plaster. To the left of the mineral
wood board is a hemp batt. I also have mag board, and was doing
water demos on all. I let people smell our eatable food grade mineral silicate paint vs latex that almost knocked them out most builders use. ROMA and Heim are the only to mfgs I know, I have to ship in since quality paint is not available. When I say quality I mean no MVOC, not low VOC sales hype.
The best part was competition and suppliers coming over to learn about what I was doing and hear my presentations to potential clients I had to kick to the curb