Thursday, November 13, 2008

My house has rabies

My house doesn't have rabies, but it looks like it does. It's foaming everywhere.

Let me backtrack. As you know the house is from 1859. There was zero insulation in the walls (which was nice for gutting). Most places there was plaster&lathe, lap sheathing and siding. And some parts of the house didn't even have the sheathing. One small part of the house that was rebuilt did have some R13 fiberglass insulation...but not much and by the time i had gotten to the house a raccoon had made that his home.

I wanted some high efficiency insulation. Because I plan on making this my homestead I was willing to pay the incremental cost up front for lower heating/cooling bills in the long run. I hired Arbor Insulation, one of the few 'open cell Poly-urethane' players around, to take care of me.



There are a lot of 'closed cell' guys out there who will try and convince you that it's 'structural' and 'waterproof', but the truth is unless an architect is specifying that it will be used in a structural capacity that does you no good, and unless it is below grade, it also does not need to be waterproof-that should be taken care of by an exterior weather barrier. Beyond those two things, closed cell just doesn't perform like open cell.



I haven't blogged about the inside of my house recently on account I didn't want to advertise that my electrical was completed. Now that insulation covers 90% of it everything is probably cool. Oh and i have a fancy security system.




The white stuff is open cell Poly-Urethane spray in insulation. A modern 2"x4" wall with a single layer of traditional fiberglass insulation provides an R13. 3" of open cell sprayed in insulation yields an R value of 13.4. But R-value only models conduction, the spray in severely cuts down on convection also. So that number gets 'adjusted' for the fantastic convection stopping power to a comparable R 26.7. In addition I have a 1" exterior insulation that gives me an additional R5. So the total system gives me an effective R 31.7 in the walls.....that is more then most people have in their attic. And honestly looking over the house in most places it is more then 3", more on the average of 3.5" - 4".

In the attic/cathedral ceilings they said they would spray me 5" effective at R 44.5, but again in a lot of places they out the entire 7.25" rafter.



In the basement/crawl space they sprayed 'closed cell' poly-urathane-which comes out green, but if left uncovered it needs to be sprayed with an intumescent paint. The paint is tan. I'm also using the close cell to seal a leaking brick basement wall I have.





Potentially one redeeming thing about a slowing economy is that the price of copper is plummeting due to decreased demand. It's hard to say if this will stop or slow scrappers because the slow economy might bring more desperation. But that remains to be seen.

Now I just have to pass an easy inspection on monday and drywall is en route