Saturday, October 22, 2016

Insulation sandwich

My walls are now an insulation sandwich!

When I was in college and participating in the University of Chicago Scavenger Hunt, we tried to make an Earth sandwich.  You have to get two people on opposite sides of the earth to put a slice of bread on the ground, thereby creating a sandwich filled with the entire Earth.  We kind of succeeded.  Someone in Australia did one half, and someone asked someone's TA from Spain to see if one of his friends back home could do it, but the obliging friend didn't quite understand and, instead of putting the bread on the ground, sent us a photo of a slice of bread artistically arranged on the railing of some bridge in Barcelona.  I think we got points for it anyway.

But this post isn't really about sandwiches or silly things I did in college.  It's about my grown-up life and how I got my walls insulated.

A while ago when I had a not-very-helpful home energy audit, I was told that insulating the walls would probably be the most effective thing I could do to improve comfort and energy efficiency in my house (since easier things have already been done).  Since my walls already exist, the only practical way to insulate them is to cut small holes in them and blow in loose insulation material.  However, after some back-and-forth with me, the company that did the audit told me they couldn't insulate my walls because the cellulose material used for blown-in insulation has problems with moisture and mold in old houses like mine that don't have a vapor barrier to keep moisture out of the walls, as described here.

So, for a while, I wrote off the possibility of wall insulation, even though I really wanted it.  On one of our hot Southern California summer days, I could put my hand on the interior wall, and it would feel like an oven.  In the winter, it's immediately freezing again inside as soon as the heat cycles off because the cold walls just suck it right up.

One lovely 120-degree day, I started researching wall insulation again, and I found some other resources describing different materials.  The consensus seemed to be that cellulose has moisture problems, and its fire-retardant treatment breaks down after 20 years or so.  On the other hand, fiberglass, while not as environmentally friendly to manufacture, doesn't burn, isn't attractive to pests, and doesn't grow mold if it gets wet.  So, blown-in fiberglass insulation started to sound like an option.

To do blown-in wall insulation, you have to cut a small hole in the walls every 16 inches or so (between each stud), usually one high in the wall and one low if there's a horizontal beam blocking the cavity.  You use a big blower device that shoots loose material into the wall cavity until it's full, and then you patch the holes.

Since the energy audit company didn't seem to know anything about fiberglass, I had to look elsewhere for an insulation contractor.  Searching on Yelp, I was really surprised to find that there were very few in this area, none in my town at all.  I would think there would be a lot more demand for this kind of service.

I got three quotes.  Guy #1 was super professional and willing to answer all my questions patiently, and he was willing to blow the insulation in from the outside and patch the holes when he was done.  Guy #2 didn't seem to know what lath and plaster wall construction was, didn't seem to really take measurements, and kept teasing me about all the questions I was asking, so he was immediately out (Apple Valley Insulation - avoid them).  Guy #3 seemed polite and conscientious but was difficult to schedule with, and he wasn't willing to blow it in from the outside, only the inside, and he would leave the holes for me to patch myself.

I started watching some videos and decided I really didn't want to do it from the inside.  It would have been a complete mess, the kind of thing you only do if you aren't actively living in a place.  Plus, cutting into lath and plaster is always a mess because it crumbles.  Cutting into the wood siding would be much easier.  So, even though Guy #1's price was a good bit above Guy #3, it was totally worth it to have it done from the outside and to have him patch the holes for me.  So I hired Guy #1, Superior Insulation & Acoustics out of Murrieta.  I felt like I was spending a lot of money, but I calculated it out later: three guys working for a day and a half and driving over an hour to get here, plus materials...they definitely aren't getting rich off this business.  It seemed like a fair price.

They did some exploratory drilling and determined that the newer add-on in the back was already insulated, as was the ceiling in the older add-on/laundry room.  So they did the remaining exterior walls, and they very neatly cut up some foam blocks and pieced them into the weird refrigerator alcove in the laundry room which is basically just a plywood box that sticks out of the wall.  All that was left for me to do was to paint the patches!

The weather's been too nice lately to tell if the insulation has made a difference.  Perhaps I'll post again in a year's time with a before-and-after analysis of my energy usage.

They drilled lots of holes in the exterior siding
They blew it in with a hose

The walls were empty, just siding, air, and lath & plaster.

Full of insulation
Wood plug

Patched holes ready for painting

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