|Air sealing the duct work to the subfloor. The interior side of the duct work is taped as well. I like redundancy in air sealed layers.|
The last step in air sealing this house is sealing the duct work and connections in the crawlspace. I don't know if John's house technically has what you call a crawlspace because it is built on piers and the space is open to the outside, but it seems like a crawlspace when you have to crawl and duck floor joists for hours at a time.
As I noted in an April post, the HVAC ducts are sealed with some kind of DUCK tape which really doesn't hold well for any length of time - meaning for years of the usefulness of the duct work. I did not take off all the fiberglass insulation and re-tape the ducts with a more long-lasting tape. I just could not make myself do that, but I did reinforce EVERY SINGLE JOINT and EVERY SINGLE PIECE of DUCK TAPE with a very adherent and long-lasting tape, mostly Siga Wigluv. I am hoping that the ducts are so well encased that they won't move much and the tape underneath the fiberglass insulation sheets holding the ducts together will last better.
|This tape has only been on for a couple of months and is already loosening. You can see here I have reinforced other areas with Siga Wigluv. I did that on every duct.|
|You can see all the little strips of paper from taping the pipes.|
After the sealing is complete, then I will insulate the 9.25" joist bays with 2 layers of Roxul Mineral Wool insulation - 5.5" layer and a 3.5" layer. The ducts themselves will be encased in the leftover polyisocyanurate foam which you see on your left. I haven't figured all those details for insulating around the ducts yet.
Rich finished the interior painting, John is building bathroom vanities and I am crawling around underneath the house, sneezing like crazy - air sealing which is what I do best. That's where we are today.