What to do with poorly installed open cell foam?
tomsweets
| Posted in Energy Efficiency and Durability on
I have a 1200 sq. foot california ranch with an attached carport. Recently I had a local contractor downspray the attic. He agreed to take up all existing insulation and perform the downspray. After the job I dug into the foam in 3 places just to make sure he did it right. Unfortunately, I found 2 inches of our old, old fiberclass batt insulation under his 5 inches of open cell spray foam. Should I have him demo the whole thing and redo it, or should I negotiate a reduced rate? If so, should that be 1/2 off his $1600 fee, or more or less? He understands his workers messed this up and he is ready to work with me.
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Replies
Thomas,
I would base my decision on the quality of the job. If an attic inspection shows that the foam was installed in a way that creates a decent air barrier, I might leave well enough alone and negotiate for a lower price. However, if the job is sloppy and possibly not even air tight, then the cured foam absolutely needs to be removed.
Can it be airtight if there are possible paths to the exterior walls under the foam but above the drywall? It would be possible but likely expensive to test the air-sealing, and it it only cost $1600 in the first place (sounds cheap to me for a SPF job), it may not be economical to approach the issue by testing it--I might just ask the guy to remove all the foam that's encapsulating fiberglass and re-spray those areas including enough extra to tie into the existing foam completely.
Also, why did you decide to dig into the foam? Did you have a suspicion it was not done right?
I assumed I would see scraps of fiberglass around the hatch to the attic, which is over the carport, and we didn't see anyone carting off bags of old insulation during the job
I took off a couple of sofit vents and also went up in the attic today and investigated further. The fiberglass appears to extend all the way to the edge of the roof at the wall plate, so I guess that could be a path under the foam to the outside air. Also, there are multiple areas in the attic where there are "holes" in the foam.
Also, I assumed they were going to install baffles, but they didn't, so I have no venting from the eaves to the attic.
My idea is this:
1 Have them take up all the foam and fiberglass around the perimeter of the attic. Vacuum this area totally clean
2 install baffles to communicate between the attic and the wall plate.
3. Respray the perimiter of the attic, and add a layer of foam on top of the already cured foam which is still over the living quarters. I figure that another 4 or 5 inches here would air lock that area from the time, and the perimeter spray would air lock around the outside.
4. I think they may need to spray some into the eaves after the baffles are installed because I can see uncovered wall plate through the eaves when I look into there.
I'd just ask them to re-do the entire job correctly. Either (a) the contractor accidentally failed to follow the terms of the job, and would want to make it right, or (b) the contractor willfully ignored the terms and should be compelled to do it right. Leaving all the fiberglass and blowing foam over it... that's nuts... they need to know that they blew it completely.