Use of plastics in modern construction

Modern construction wraps us up in plastic. I think its to prevent moisture in the walls, but someone correct that if it's for a different purpose. Also our paints are acrylic, a type of plastic. I would like to hear more ways it's used in building, as I believe the plastic homes are a large contributor to society's disconnected state.

Hello Ilyusha,

I could not agree more. I am often having this debate on several fronts. Most recently on Linkedin (http://www.linkedin.com/groups/Tyvek-applicability-in-Historical-Conservation-2740091.S.246938153?qid=19b476c8-bb1b-4ad3-8fdd-e09a4ecad12d&goback=%2Egmp_2740091) I find many moder paints, house wraps, and their equivalent, unhealthy and, just as important, unecessary for healthy and enduring architecture.

Regards,

jay

If someone wants to build a home without any use of plastics that's their choice. I think its more than a stretch to blame the ills of society on plastic housewrap and paint.

Plastic obviously comes from oil. Oil is an incredibly useful resource but is often wasted and misused. I dont think its fair to entirely condemn such an abundant, useful resource any more than it is to condemn a race or group of people.

If you could use a small bucket of oil to prevent the burning of 5 tons of dirty coal and avoid 100 hours of manual labor is this not a wise use of resources? Transportation is the real problem when it comes to the misuse of oil. With buildings and homes, oil goes a long way in reduced future maintenance but more importantly, the burning of un-renewable resources to heat and cool our building long into the future.

With buildings and homes, oil goes a long way in reduced future maintenance but more importantly, the burning of un-renewable resources to heat and cool our building long into the future.

Hi Brian,

As is the case with you and I, we see this issue differently. I would not blame the ills of society on plastic, but it would be a cleaner and healthier place if we did not abuse it the way we have. As for the use of plastic in architecture. It just is not necessary to use it to have an efficient home. The outgassing of most of these products is a "tiger" in the room that most mainstream builders do not want to talk about or acknowledge. It's the "emperor's new clothes," all over again, every time a major manufacturer creates a new paint, house wrap, carpet pad, etc. etc....WE DON'T NEED THEM.

New and Modern is just that, "New and Modern"...it's not better, or even more efficient in the long run. I just helped another client tear off all their housewrap, as it trapped moisture in the walls and was facilitating the growth of black mold, lowering what little R factor they had and generally destroying the health of the home and it's occupants. Housewrap is now gone, timber frame is cleaned, siding looks great, and used less heat than they have in 3 years. These products, once buried in a wall are unseen and hard to truly evaluate. Homes need to be draft free, not air tight, which I still read on a daily basis in more propaganda bassist literature be pumped out from these chemical and plastics laden manufacturers.

I have written this here many times now, but it deserves repeating once more. We have built efficient warm and extremely enduring homes for thousands of years without all the fancy gadgets, gizmos and gimmicks that every major manufacturer wants to convince the consumer culture they "really must have and use," to have a safe, warm, efficient home. It is simply not the truth.

Regards,

jay

Thanks for keeping things balanced Jay. This thread certainly has the potential to become a debate and discussion on society and technology and there are certainly no losers or winners here. This is a fascinating subject that I hope fits in well to the world of permaculture.

Details first, I agree that things would be better without the abuse and that its not necessary to use plastic. However, plastic is a resource and a tool that can have appropriate uses in our dwellings. I feel that a balanced approach is to reduce its use as much as possible but not restrict it to the point that it makes things more expensive, less durable or less comfortable.

As for off-gassing, hard plastics are much less of a concern than soft plastics. Carpet, in my opinion, should never be used, ever. Even the stuff that doesnt off-gas traps dust which is the bigger Indoor Air Quality IAQ concern to me. For those that are familiar with my views on IAQ: Outdoor air is always cleaner than indoor air. IAQ is best served with mechanical ventilation. You can build a home entirely out of completely natural materials but the 100% plastic home with a properly installed HRV (or meets the ASHRAE 62.2 ventilation standard) will probably have better IAQ than the 100% natural home. Plastic is a major component of most ERVs and HRVs. In this example, the device made by manufacturers out of plastic parts is doing more to clean the air inside of the home than any natural material could. I find it a tad ironic that the electronics inside of the computers we are on are probably poisoning us more than our old carpets or rugs. We dont need computers but damn they make life easier.. or do they?

As for the housewrap example, it sounds like you are talking about an interior vapor barrier (installed to the inside of exterior walls) which are not used anymore except the most extreme northern climates. By all means, interior vapor barriers cause problems and should be removed when possible. If the problems you found were indeed at the housewrap layer then it usually means that there is too little insulation to keep the structural sheathing layer above the dewpoint. Air leaks are another source of moisture intrusion and scientists consistently find more problems with condensation from air leaks than vapor diffusion.

Housewrap should be completely outside of the building envelope and in a tight home would not off-gas to the interior at all. Plastic housewrap has taken the place of tarpaper and is meant as a weather resistive barrier WRB. It blocks the bulk water that makes it past our siding or cladding systems. I dont feel strongly either way about plastic housewrap vs tar paper as long there is a WRB to protect the structural elements. The nice thing about WRBs is the ability to mechanically lap them over flashings. I know that Jay specializes in construction that dates long before tar paper and perhaps you can enlighten us on good or better options for dealing with this issue.

Iam curious how you are distinguishing from draft-free and air-tight. To me, it sounds like the same thing. Many natural builders advocate vapor permeable walls. I think its ok to have at least one layer that is vapor impermeable as long as vapor can dry in either direction. Two different vapor impermeable layers can trap moisture between them.

Yes big companies are jumping on the airtight bandwagon but this movement was not started by them. Air-tight super insulated construction was born in the US and Canada during the energy crises of the 70s. The movement was pioneered by hippies and engineers looking to become energy independent. As the crises died, so largely did this important building movement in NA. Europe picked it up and has transformed the way they build over there. Some may say for the worse but for those interested in energy use and global warming the housing stock has drastically improved. Luckily, things like the passive house movement are catching on over here and we are contributing to the mix with Net-zero homes and buildings which may offer a more cost-effective approach to energy sustainable building.

I think people strolling out on the green building path tend to focus on materials. Energy use is the tiger as I see it. 40-80% of our nation's energy use goes to heat and cool our buildings. If we were all building traditionally, then the forests would be in even worse shape than they are now and energy use would be unimaginable. Most of the older structures (that didnt burn down) used ridiculous amounts of BTUs to stay comfortable. Building codes enforcing insulation although very weak, have made an enormous impact on the amount of energy our country uses.

Society is not the same as it was. Almost everyone has some amount of gizmos and gadgets from refrigerators, water heaters, well pumps and heat pumps; they arguably make our lives better. New and modern plumbing systems are arguably better for the environment than the old way and much more convenient. Do we need all that stuff? Probably not. Does it make our lives better? According to some Sociologists, people had more enjoyment of life in hunter and gatherer times. Many of the newer and modern things that make our lives better and more convenient contribute to over population. The long term effects of all this stuff could very well hurt human society in the long run.

Its easy to see both sides of this paradox. I consider myself a realist and optimist. I think our society is evolving for the better overall. I have a strong connection to nature and feel that its our energy use that is hurting our environment and society more than anything else. My vision and solutions of the future includes super efficient homes that are grid tied with renewable energy and have the ability to charge their electric vehicles. It will take plastic and even big manufacturers (that are owned and operated by people like you and me) to make this vision possible.