I’m ready to insulate the ceiling of my 1700 s.f. ICF house near Hagerstown, MD.
I wanted to have Icynene foam sprayed on the top of the ceiling drywall to seal the house completely. Just a thin coat, then blown fiberglass on top – the best of both worlds…just one problem:
the Icynene bid is $3,900 (and he can spray tomorrow if I give the word)
How do I determine if it is worth it?
I only have $65K in the house so far (owner built) and want to stay under $105K total, so naturally $4K is a big chunk to swallow. But I’d pay it if I knew the payoff would be forthcoming, but not if I am pursuing diminishing returns.
So…am I throwing my money away?
Also, the Icynene guy swears he cannot blow thinner that 3.5″ – sound right?
I thought about buying a foam kit and just sealing over the tops of the wall plates and can lights ~$600 – would this be a smart (cheapskate) option that would have similar results?
Any thoughts appreciated…
Replies
I wouldn't combine both systems. Save your money, use the fiberglass. As far as the 3.5" minimum he is right. I had an Icynene quote and he asked how thick I wanted it. I thought he was joking.........How can you control the thickness with a huge set-up like that I thought. I told him to make it as thin as he could and he wrote the bid accordingly. They ended up filling the 2X10 floor joists almost full!!!!!Anytime I have used it in an attic it was applied to the deck and not the drywall. I would think with it's great expansion and the fact that it basically starts as a liquid that it could cause some serious drywall problems. Have you ever seen someone overfoam a door and not be able to get it open? What if it got between the rafter/truss and drywall?
the half pound density foam, like Icynene, does not have a tremendous force during expansion. It simply expands in the direction of least resistance. So getting in a crack between the ceiling and the joist will never create enough force to blow it off or even seperate it from the joist. I have personally have one small portion of ceiling unexpectedly fail when I was spraying the attic. Of course the first thing through the rock was my foot, not the foam!!Stu
It's a toss-up
On a tight construction budget I'd probably use that self-help kit myself and blow chopped FG.
The thing is - one of the big advantages of a foamed house comes from controlling infiltration. To get that full benefit, you need to do whole house from sill to ciel.
You don't have an extreme climate so payback on the icy would be slower
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Thanks - I've decided to skip the foam. Y'all saved me $4K. The house is pretty small and I might do the penetrations and wall plates with the home foam kit.
Plus the cedar ceiling has some spots where the truss chord was high, and if foam gets in that gap, I'll have a mess to contend with.
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Great, now you mention cedar ceiling.
I would have said yes without a doubt if you have wood ceilings w/o an air barrier.
Impropper wood ceiling instilation can be the biggest heat loss in a home, and the most costly to fix.
I like hard (closedcell) foams better han soft in this situation. Around here it's $1.70-$2.00 for 2" of hard foam.
Best of luck
Garett
Garrett - somehow I missed your reply - I was out of town for a while... I have poly between the cedar and trusses, so air shouldn't move through.
Of course I could still change my mind since the ins. contrractor is taking his sweet time showing up...
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I'm doing much the same in Winnipeg Canada (-49c last night..with the windchill....just -34c without!)....I considered all the possibilities and came up with 6mil poly...well sealed...see a book called "building in a cold climate" or something darn close...(I don't have it here..its at work)with R60 of blown Roxul...it seems that fiberglass gets air currents in it the colder it gets outside...so the effective R factor decreases as the differance between interior and exterior temp increases...since its -30c outside and +20 inside that's a heck of a differance....think about the Roxul (rock wool)....anybody have thoughts about that recomendation...I'm all ears too!....Tim in Winnipeg
at those numbers he's charging $0.65 per bd ft. That is very high.
Are there any other spray foam outfits available to use?
I spray foam for a living so take it for what it's worth, but I feel foam is the best. It's much more fool proof than running around 1700 sq ft with a can of foam or caulk and trying to get ever penetration. Did the drywall guy miss ANY nails into the joists? Of course not!
I'm guessing a second bid could save you a grand right off the bat.
The 3.5" min thickness is exagerating a little bit but not too far off. I use ~2.5" for a min.
Sorry I didn't hit this post earier. Hope this helps.
Stu
Did the drywall guy miss ANY nails into the joists? Of course not!
Actually, the question is did they use any - the crew hung the 12' boards with a few nails on the perimeter, and only 2 SCREWS in the center. (plenty of glue though)
No one else with a foam rig is close or answers the phone.
Anyone near Hagerstown MD wanna come seal my 1700 s.f. (new construction) attic with foam? I'd still be game if your price is right...
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Hi MAsprayfoam.
Do you ever run into problems with local building inspectors regarding attic ventilation issues? My understanding is that if you totally air-seal the underside of the roof with Icynene, you don't need to vent the attic.
TFToolfanatic (a.k.a. The man formerly known as "Toolfreak")
I'm curious as to the minimum thicknesses that are needed to meet code. I do not know if there is a national code, or if they are all localized, but let's say one needs an R17 to meet code requirements for attic insulation. That's about 5" for Icynene, no? And at would thus equate to $3.25/SqFt to the original poster. At 1700 SqFt this should be >$5K. So, what am I missing here? I assumed Icynene was R3.5/inch thickness and seeking an R17 insulating goal.
Nuke - I (the original poster) was looking to seal the attic, then blow fiberglass on top to code.
The Icynene guy couldn't do less than 3-3.5 inches.
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I do run into the reluctant BI on occationally.
I try to simply educate them with literature from 3rd, independent, parties. Also show roofing manufactures that fully warrenty this type application.
The IBC recently approved an ammendment that approves this type insulation as long as the insulation in question allows no air movement (foam).
Stu
It's also reconized by the Connecticut Supplement to the IRC.Andy
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