Cold Roof, Warm House (Part 2)
After the foam insulation contractors had come and gone, the house had an entirely new feel. Of course the house was still in its "gutted to the studs" state, and it was March and I wasn't heating the place so it was still cold, but I was surprised at how much quieter the house felt both in terms of sound and air flow. The hammers banging didn't echo quite as much and whatever heat that was generated by bodies working actually raised the ambient temperature.
Unfortunately, the contractors had left quite a mess. Despite their promise to use drop cloths, they didn't. The foam overspray was everywhere. And even though the house was clearly a construction site which might give some excuse to their negligence, there were bathroom fixtures and original flooring that got covered with foam insulation droplets. Two years later, I'm still cleaning it off of the upstairs floor.
Not having worked with many subcontractors to that point, I made the mistake of not supervising them closely. I tend to want to stay out of the way and let professionals do their work, but the bottom line is that I was paying them. They came back and cleaned up a reasonable amount of their mess before I mailed the check.
The next task for insulating was sealing up obvious points of infiltration with spray can foam. As I mentioned in my last post, this is a messy job. It just seems impossible to apply this stuff without getting on places you don't want it.
Installing fiberglass batts in the exterior walls was next. The original walls are timber framing, sheathed in 1" pine. With this kind of construction, studs are placed only as needed to provide nailers for the sheathing and windows, and to provide support during construction. Knowing that I was going to cover the interior walls with sheetrock, I added more studs for mounting the panels. In most cases I was able to place the studs 16 inches on center and this allowed me to use the standard size fiberglass batts but there were a lot of places where I had to cut the batts and place them at odd angles to fill all the spaces.
After installing the batts, I then installed 1/2 inch foil-faced foam board over the top of the fiberglass. This not only increases the R-value of the walls but also provides a vapor barrier. The seams between the foamboard were sealed with foil tape to increase the effectiveness of the vapor barrier.
My efforts were not in vain. Whereas the prior owners had burned 1300 gallons of fuel oil the last year they were in the house, we burned 475 gallons of fuel oil, and 2 and half cord of wood the first year. Using today's prices ($2.60/gal oil and $150/cord green wood) we saved $1770 in just the first winter, and that was before insulating the upstairs walls. (The priority was to get the downstairs in move-in condition before working on the upstairs.) So far this year, after getting the upstairs insulated, we've only had 200 gallons of oil delivered and I don't expect to burn more than 2 cord of wood. We might just get out of this winter spending less than $1000 on heating.
Super-insulating the house and relying as much as possible on wood heat is more than just an economical and comfort-based decision. The battles we're fighting for energy resources are real and far-reaching. Shrinking our "carbon footprint" is a moral issue as much as it is economical. (At least that's what I keep reminding myself when I'm splitting wood and lugging it into the house.)
p.s. Check out the following Builders Square animated How-to Tutorials associated with this post:
Climate Control: Insulating an Unfinished Attic
Hanging Drywall
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