Wednesday, October 21, 2009

Foam Catastrophe

This summer, we decided it was about time to investigate some leaks we had in the roof. Water stains showed up on the front bedroom closet wall again, after I rinsed down the solar panels thoroughly, in a place where we had them three years ago. I thought we had the leak fixed, but it was just the drought, there hasn't been enough rain to really show up. So we had the drywall taken out on the front and back bedroom closet. The back bedroom closet was smelling of mold, as was the front, though there were no visible leak stains.

After finding and fixing the leaks, and having the mold treated, we were left with two open ceilings. Previously, they had been packed with fiberclass insulation, but I had some closed cell foam left over from the solar hot water closet installation, so yesterday I decided to try foaming the back closet ceiling. Since the temperature at night has been below the recommended temperature, I put on an electric heater for four hours in the morning to heat up the closet. After it seemed warmed up enough, I donned the foamer's Tyvak suit and went to work. Here's me in the suit.

 If you've ever done foaming, you know that these suits are absolutely essential because the foam goes literally everywhere and especially where you'd rather not have it, like in your hair and clinging to the hair on your arms.

I had two sets of tanks (2 tanks per set, one with the resin and one with the setting agent). I took the first tank and foamed up about three quarters of the ceiling before it started to run out of pressure. When pressurized foam dispensers run out of pressure, it's hard to get them to the target without actually being up against it, not possible on a high ceiling. In addition, the foam started peeling off the ceiling at the high side, possibly because the ceiling didn't get heated enough by the electric heater.

In any case, I shut down the first tank set and started up the second. This set was nearer the heater. Right away, I knew something was wrong. Instead of expanding out into billows of foam, the mix came out as a blue fluid that didn't blow out much. I tried it a while, thinking that maybe it was a startup transient, but the fluid started dripping down on the ladder and the tarp covering the floor. So I shut down the tanks. Here's what the tanks looked like after the ceiling had about stopped dripping;

You can see the blue fluid (kind of like the water in a toilet that has one of those sanitizers in it) dripping off the shelf. I think the problem was that the tanks were too warm. These foam systems have a relatively small temperature range over which they will set.

At any rate, there were small pools of fluid on the floor and the ladder was dripping with it. Trying to figure out what to do, I read the instructions and it suggested sopping up spills with sawdust. Seeing as I didn't have any, I decided to try kitty litter (works for oil spills for example). I went to the hardware store and got a box of kitty litter, a plastic trowel, and a couple of large plastic containers in which to put the refuse.

The kitty litter worked fine, sopped up the fluid, and I used newspapers to wipe down the ladder. Then I took the ladder outside on the driveway, washed it down with a mixture of ammonia and detergent (as recommended in the directions), and hosed it off. The chemicals in the foam are water soluable and nontoxic, so there was no problem with washing it outside. I disposed of the tanks in the plastic containers along with the kitty litter and the rest, but left the tarp on the floor to catch any remaining drips. Today, it looks as if it is done dripping.

The result was not what I had expected, but about three quarters of the ceiling is foamed up. Here's a picture:

The bluish color at the upper end of the rafter bay is where the second tank failed to foam.

I think I'll probably talk to a professional about finishing the ceiling. Closed cell foam is the best insulation available (R-6 per inch, 2x the R-3 of fiberglass batting and much better for moisture and air sealing) but it is a difficult material to work with which is probably why these larger two component systems aren't available through Home Depot. I've done a couple of major foam projects now, and I use it a lot for small touch ups, like around electrical outlets. I think there is a lot the manufacturers could do to make the dispensers easier to use and less likely to waste foam by spraying it everywhere, but I'll probably keep using foam (though not for a large job I do myself) since it is convenient and the best insulation for the price.

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