One Week, Big Difference

It’s truly incredible how much can happen when a whole crew of people actually show up and work. We’ve seen this from friends and family during demo days, and we saw it when we had the second floor and attic framing done. Now, we’ve seen it with the exterior of the house, and it’s not done yet!

The house has been house-wrapped for quite a while now, and that house wrap has been slowly failing because it’s not meant to be exposed so long. The crew showed up last Thursday and we discussed two options, foam over house wrap, as I had planned, or house wrap over foam, which they were more familiar with.

I’ve come to believe that even when the information I’ve read suggests advantages to one way over another, if both ways work, you go with the one the contractor is familiar with. This is for a few reasons. First, obviously if they’re familiar with it, they’re more likely to do it correctly, quickly, and without unexpected issues. Second, if something goes wrong down the road, they can’t say it’s because you made them do it a different way.

In this case, there’s an additional advantage, which is that it really simplifies the flashing details. The possibility does exist that if water ever did get behind the wrap, the wood is less protected, but it’s both less likely because of the simpler drainage plane, and they’re using Blue Skin instead of traditional house wrap, which is both water tight but vapor permeable, and thus allows drying to the outside. That’s important when you’re using closed cell foam inside, like we are, which may prevent drying to the inside, because trapped water leads to mold and rot.

They also reset the windows, using the clips in the correct way to set the windows to the correct depth for the finished siding and trim. They installed the giant stack of rigid foam and when that ran out, they got some more. Here there was a hiccup, because I noticed a giant stack of pink XPS foam, rather than the polyiso foam I was using. There are a few reasons to use polyiso over XPS. Better insulation value, radiant barrier in the form of the foil face, less damaging to the environment in manufacturing, and most relevant to us, better fire protection.

We’re right on the property line on the North side, and three feet or less to the neighbor’s house. Our neighbors actually had to put exterior drywall over their sheathing for fire protection, but in our case, the polyiso foam acts as a fire barrier, not burning until it’s over 800 degrees.

With the windows reset and the foam installed, they covered everything with the Blue Skin and flashed the windows with tape. I had to scramble with my nephew Aaron over the weekend to get the back porch ledger blocking installed, so they can put the Blue Skin over it and I can put on the ledgers. When we though the house wrap was going on first, that blocking would go after, but with the foam going first, it needed to go on right away. We also got the mounting point for the wall-mounted AC unit bracket prepped. These are just pieces of 2x framing lumber backed by 1/2″ plywood to get flush with the 2″ depth of the foam.

This week, while the exterior was still going strong, both the electrician and the plumber showed up and started getting rough work done. Most of the electrical conduit in the second floor and attic is in at this point. Sarah ordered a porta-John to put in the back, since the GC never got one. I got really frustrated trying to finish up the rough install of the radiator lines in the attic, but I think I’ll have it done in the next few days.

We’ve got more nephew help this weekend and we’re going to try to knock out more of the interior wall sound insulation, both the acoustical tape as well as the batted mineral wool, and possibly start the radiant panel install.

Once the last of the Blue Skin is done, they’re going to start on the furring strips and the actual siding. In another week, the exterior of the house is going to go through yet another transformation. We’re pretty excited, even with all the constant banging and thumping while we work from home in the basement.