We are getting ready to build a home in se minnesota and am wondering which way to go and benefits / drawbacks to blown in fiberglass insulation in the walls or blown in foam. Dont really know much about either but I would like to look a little intelligent to the contractor we choose! Thansk for the input!
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Dense pack cellouse can be blown in either wet or dry. Cellouse has a green ratting being that a percentage is from post consumer pproducts. When blown in dry it is done after you have sheet rocked and you patch small whole after. When done wet like on steep cielings or poteial mois areas ofr ares that will be exposed you can apply the material wet and then is shaved off.
denscells can be blown thru nett stapeled over studs before sheetrock goes up. Irt does not settle.
Same with BIBBs blown chopped fibreglas.
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Thanks! Do you feel as thouhgh the pressurized gun that applies denscell is adaquate post sheetrock? Have you experienced setlling via this method? What are folks thoughts about hot/ unvented roofs? Is a dense cell or a foam preferred?
Edited 10/4/2004 7:16 am ET by Kev
My experience with cellulose is primarily in removing it for remodels after it has been installed either by open blowing before sheetrock or by retro blowing in finished walls. Seems to me that the blown into finished older walls ends up with some settling but that when they can see what they are doing through the net mesh, they get it all full.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
My understanding is that the icynene foam insulation is more effective and doesn't sag or settle over time as the blow in cellulose is reported to do. In my area it is also 15% or so more expensive. The installation crew has a lot to do with the quality of the finished product, also. The last icynene foam job I saw was rather sloppy and the installers overfilled the tops of the walls so the insulation crushed the plastic soffit baffles. But the homeowner said that the insulation was the best he had ever seen, especially in the ceiling of his bonus room. He is a general contractor, too.
Blown to a reasonable density in cavities, cellulose won't settle and provides a good air seal. Cellulose will settle in loose fill applications such as an open attic, but the FTC requires that the R-values for a given thickness published by the manufacturer be derated to reflect this settlement. You get settled what the bag says you get freshly blown.
AndyArguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
I have yet to decide on the pros and cons of icynene vs corbond - both camps have their sales pitch. But I am leaning towards corbond. Foam insulation is considerably more expensive than blown. I will use the blown in my vented truss areas and corbond for the unvented vaulted ceilings. The advantages of foam is no air penetraton and therefore no R-value. Vapor barrier is not required. I also have a whole-house ventalation system to remove interior moisture.
Is Corbond a closed cell foam? I believe Icynene is open cell. I'm pretty sure that the IRC requires either engineering or the use of closed cell foam in unvented roof assemblies.
AndyArguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
From what I understand (and I'm no expert just an owner builder trying to do due diligence) you are right. The closed cell and open cell both have their arguments. I have had three "foamers" visit the site, take measurements and provide estimates. They have all been foaming in the Seattle area for over 10 years (one corbond, two icynene). They all "spray to the lid". And they are aware that in my county they could be a little behind the learning curve on foaming technique but in the counties they primarily work in, spray on unvented roofs is the only way to do it. I have collected information from both suppliers with studies on foamed unvented roofs. They are very thorough, backed by long term experience. I believe this is the correct way to do it and will work to "convince" my building department of it.
PS I need to reread "Zen and the art...." it's been almost 30 years.
Corbond is closed cell insulation. I had it sprayed directly to our roof deck with no venting. The attic is not hot in the summer or cold in the winter. The dew point is eliminated so there is no condensation.
Thanks for the info.
AndyArguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
Andy, the building science people have studies showing no vent neeeded with foam there, but some local jurisdictions still fight for the old ways without understanding. Corbond has been on the forfront of proving to them that they need to wake up and smell the coffee, speaking of which...
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
>>but some local jurisdictions still fight for the old ways without understanding.
Ain't that the truth. Around here some local BOs inspect insulation. You jump through all the whoops to do what really should be done and then they insist that you need those vents and read you the code verbatium. Another sore spot with me is crawl space ventilation. They really need to get up to speed with these things. Likewise, there are a lot of us builders out here who need to be up to speed as well.
They also need to understand that what works in Buffalo, doesn't work in FLA. And what works in one of these areas doesn't work here in VA.
k
Well, if your area has adapted the 2003 IRC, then your AHJ has some 'splainin' to do. Yeah, they do tend to be sticks in the mud, some of 'em. Others are right on top of change.
AndyArguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
I just put blown in cellulose in my new house. We drilled 1 1/4" holes
in all the exterior cavities thru the drywall.. 2x6 construction The blower has to be set right in order to get a good density. There were instructions on the side of the blower. We didnt see the instructions at first, just started
filling. Lucky for us we figured out that the density wasnt tight enough. After following the instructions on the setup we got the cavities packed really tight.
Its a big mess, Anything that ended up on the floor was bagged up. I will dump that in the attic. We did blow the attic. Put baffles in the
soffit areas then stuffed R-19 batt around the baffles. We get alot of very strong winds. I didnt want the wind to blow the blown insulation
into my soffits.
The machine created a very strong static charge. I kept getting shocked.
A very fine dust has attached itself to the walls. They need to be vacumed up. Several times I think. Plus use a towel to wipe the walls ( and Ceiling).
Put the drywall plugs back in using a liberal amount of joint compound. leaving them recessed about 1/8". That will make it easier
to smooth the plugs over with your next couple coats.
It tooki us 2 days to do all the exterior walls and the attic in our 4000 sq ft house.
My area hasn't adopted anuything, but I'm curious what and AHJ is
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Authority Having Jurisdiction. Local building office.
Jon Blakemore
I could see remolding being a nightmare with dense pack. Boy and how do you remove the foam stuff? I have also foam if preferred in roofs with steep pitches do to gravity, settling. What are your thoughts on house wrap materials? I use the remay brand house wrap as well as their roof wrap. There are those ballistic gore-Tex wraps that are nicer than some jackets. I feel as though you really just want to keep you insides dry. I am not sold on this dual beathabilty thing. Most folks need fans in their kitchen,bath and basement dry. Knew construction can do this these days.
House wrap is not one of those things that sets me off. There are bigger issues in the world I live in.
But I'll argue about hanging cabinets with SR screws 'till the cows come home
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"The advantages of foam is no air penetraton and therefore no R-value. "
You want to re-phrase that one? You are right that sprayed on foam eliminates conductive heat loss which is what I think you were trying to say. That fact eliminates dew-point condensation.
R-value is resistance to heat loss, which is the goal here.
Corbond has the best R-value of the lot, flowed by Icy, then cells, then bibbs, then the poorest - FG batts
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I had the same issue as you and am also in SE MN. If you read these replies, you'll get a good primer on the value of FG versus cells...only problem here being you'll have a hard time finding a contractor that will blow in or dense pack cellulose.
But here's johnnyd to the rescue...try Advantage Insulation...507-932-4089. They specialize in cellulose, gave me a reasonable quote, got there on time and did a nice job.
Here's thier site:
http://www.nuwool.com/contractors/finddealer/minnesota.html
Here's another one to try:
http://www.cocooninsulation.com/sales-contractors2.asp
Edited 9/29/2004 12:16 pm ET by johnnyd
Edited 9/29/2004 12:19 pm ET by johnnyd
Edited 9/29/2004 12:22 pm ET by johnnyd
Thanks forthe reply on the blown cellulose. You mentioned you are in se minnesota, anywhere near Winona? Could probably use some of your contacts! Thanks!
Just about an hour west and south of winona, near Spring Valley. Did you try advantage insulation? The guy that runs Advantage is also a GC for general residential, I believe.
Thanks for those links! A wealth of good imformation.
k
Blown FG is not a great material. You can't get a dense pack with it. Try for cellulose instead.