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Author	Comments
charles hogan Posted: Apr 08, 2007 01:52 PM	Foam Shrinkage Has anybody else had a problem with Insulstar 2lb foam shrinking? I applied on top of ceiling sheetrock and it shrunk 3/8 of an inch two months later when it turned cold and pulled the rock up, now the ceiling looks like a washboard. I applied 5.5 inches as needed to meet state insulation specs in multiple passes. Haven't had any help from NCFI. I have been told by Corebond to apply no more than 2" per pass to prevent such problems but was told nothing from NCFI when I started spraying their foam. Now looking at paying thousands of dollars to replace the ceiling, there go's the profit!!!
Posted: Apr 08, 2007 08:41 PM	Was the substrate dry and warm that you applied the foam to? If it was done this winter and you did not heat it may have been too cold for proper adhesion. Or if you used heat and condensation occured and did not evaporate before you applied you could have similar results. Tim Granite State Spray Foam Co.
charles hogan Posted: Apr 09, 2007 12:06 AM	I installed it in late summer and it was dry with no vissible signs of any problems, it appeared to expand normaly. I cut samples and could see no sign of charring or discoloration through out the foam. It was when it turned cold that it began to shrink slowwly over a five week period. I think maybe a bad batch but no support from manufacturer.
Posted: Apr 09, 2007 08:24 AM	It sounds like spraying down onto a cieling is a big risk for the applicator. I'll think twice before I ever do that. Would .5lb foam have had the strength to pull up the sheetrock? Best of luck with that thing.
SprayFoamSupply.com Posted: Apr 09, 2007 09:06 PM	I have sprayed .5lb down onto the drywall on numerous jobs without issue, George
Thomas Kasper Posted: Apr 09, 2007 09:25 PM	George, What is the minimum thickness of .5 pound foam that you will put down on drywall? Using the hybrid method of foam, then blown insulation on top of foam. Or, do you just sell the required r value for the attic with the foam to the correct thickness?
Gerry Wagoner Posted: Apr 10, 2007 04:22 PM	Hello pardner. The problem is not "shrinkage" but rather the cooling contraction of spraying the material too heavy in one pass. In this case the weak link was the .5" drywall span across the joists/truss chords. I have a small section of my office ceiling where the same thing happened, and that was 141b foam (2003). We didn't even notice it until I saw that the knockdown ceiling was real uneven, and I got on the ceiling contractor for it and he said that the thing was super uneven. "Sure", I thought. We got a 4' level out and sure enough it was uniformly wavy across the area. If we had caught it in time we could have had the spackler fix it. Insulstar is excellent foam, and it has a lot of strength if applied too heavy. I wish I had a better answer. A good spackler should be able to level it out, although it will take some material & time. all the best, olger
charles hogan Posted: Apr 11, 2007 03:44 PM	I don't believe it was contaction due to application since the shrinkage did not happen until it got very cold a few weeks later. I have used at least 40+ sets of insulstar and have had only minor problems before, none related to shrinkage. Local salesman and his boss claimed in their 20+ years they never have seen this happen before. If it was contraction I would think it would of happen right after application and not waited for weeks.I don't believe spackle will fill 3/8 of an inch void and keep my customer happy. What is 141b foam?
SprayFoamSupply.com Posted: Apr 11, 2007 08:55 PM	Tom, I install the required 10" to get R-38. I do not do hybrid systems. George
Thomas Kasper Posted: Apr 11, 2007 08:55 PM	141 B was the blowing agent that was used prior to the 245 blowing agent. It was used until 12-04 when the price of foam materials skyrocketed.
Posted: Apr 12, 2007 12:47 AM	r-49 for energy star,,,doe recommendation for my cold climate zone...this is what our energy supplier wants for rebates... r49@3.8/inch=12.8inches physics is physics r19 oc in an attic in our cold climate zone is not enough insulation to stop the convective flow of air...when hot meets cold,,,condensation occurs... we cant tell someone that by buying the upgrade to foam that they are going to save bu-coo bucks and then apply 1/2 to 1/3 the neccessary r value and expect it to happen... 3x the performance at equal rvalues means apply to r 38 or better and then you may see the savings... i too, do not apply the hybrid systems,,i let the competition have that business,,, they like me,,,kinda,,, foam-it!
Gerry Wagoner Posted: Apr 13, 2007 10:15 AM	3/8" Of an inch across 16" framing (or is it 24") is excessive. Big time excessive! A water-blown foam might have been better in this case. 141b was the standard blowing agent from April `93 to 2004. Prior to that it was the best foam ever: R-11 Freon foam. Carry on, olger
charles hogan Posted: Apr 13, 2007 11:47 AM	The rafter spacing was 16 inches on center, I used to use water blown insulation and have never had any problems but I believed the salesman and the co. After asking them if there was any difference in installation between waterblown and their product they claimed no, now it's been 5 months and they still have not decided what they are going to do. Be careful with what they tell you.
Jason Kron Posted: Apr 18, 2007 09:52 PM	I have seen one or two projects where the drywall ceiling has had a wavy finish a couple of months later. Some of my guys have did one of two things to keep this from happening the first is not to apply more then two inches ( acually they are trying to stick with 1.5") the second is putting down a tar paper to break the bond just the drywall not your structural memebers. In my opinion spray it a little thinner in first lift. Also I would be catious in spraying anyones foam thicker then 2" per lift. Or at least try to stay in that range give or take. I haven't seen anyone's that have really worked yet.
Timothy Sonney Posted: Apr 19, 2007 12:58 AM	What we have done is no more than a 2" pass at a time, but also sprayed directly on the 2x8 or 2x10 over top and continue on to the next rafter cavity. This glues everything, and we have yet to see any issues.

Author

Comments

charles hogan

Posted: Apr 08, 2007 01:52 PM

Foam Shrinkage

Has anybody else had a problem with Insulstar 2lb foam shrinking? I applied on top of ceiling sheetrock and it shrunk 3/8 of an inch two months later when it turned cold and pulled the rock up, now the ceiling looks like a washboard. I applied 5.5 inches as needed to meet state insulation specs in multiple passes. Haven't had any help from NCFI. I have been told by Corebond to apply no more than 2" per pass to prevent such problems but was told nothing from NCFI when I started spraying their foam. Now looking at paying thousands of dollars to replace the ceiling, there go's the profit!!!

Posted: Apr 08, 2007 08:41 PM

Was the substrate dry and warm that you applied the foam to? If it was done this winter and you did not heat it may have been too cold for proper adhesion. Or if you used heat and condensation occured and did not evaporate before you applied you could have similar results.

Tim
Granite State Spray Foam Co.

charles hogan

Posted: Apr 09, 2007 12:06 AM

I installed it in late summer and it was dry with no vissible signs of any problems, it appeared to expand normaly. I cut samples and could see no sign of charring or discoloration through out the foam. It was when it turned cold that it began to shrink slowwly over a five week period. I think maybe a bad batch but no support from manufacturer.

Posted: Apr 09, 2007 08:24 AM

It sounds like spraying down onto a cieling is a big risk for the applicator. I'll think twice before I ever do that. Would .5lb foam have had the strength to pull up the sheetrock?

Best of luck with that thing.

SprayFoamSupply.com

Posted: Apr 09, 2007 09:06 PM

I have sprayed .5lb down onto the drywall on numerous jobs without issue,

George

Thomas Kasper

Posted: Apr 09, 2007 09:25 PM

George,
What is the minimum thickness of .5 pound foam that you will put down on drywall?
Using the hybrid method of foam, then blown insulation on top of foam.

Or, do you just sell the required r value for the attic with the foam to the correct thickness?

Gerry Wagoner

Posted: Apr 10, 2007 04:22 PM

Hello pardner. The problem is not "shrinkage" but rather the cooling contraction of spraying the material too heavy in one pass. In this case the weak link was the .5" drywall span across the joists/truss chords. I have a small section of my office ceiling where the same thing happened, and that was 141b foam (2003). We didn't even notice it until I saw that the knockdown ceiling was real uneven, and I got on the ceiling contractor for it and he said that the thing was super uneven. "Sure", I thought. We got a 4' level out and sure enough it was uniformly wavy across the area. If we had caught it in time we could have had the spackler fix it.

Insulstar is excellent foam, and it has a lot of strength if applied too heavy. I wish I had a better answer. A good spackler should be able to level it out, although it will take some material & time.

all the best,

olger

charles hogan

Posted: Apr 11, 2007 03:44 PM

I don't believe it was contaction due to application since the shrinkage did not happen until it got very cold a few weeks later. I have used at least 40+ sets of insulstar and have had only minor problems before, none related to shrinkage. Local salesman and his boss claimed in their 20+ years they never have seen this happen before. If it was contraction I would think it would of happen right after application and not waited for weeks.I don't believe spackle will fill 3/8 of an inch void and keep my customer happy. What is 141b foam?

SprayFoamSupply.com

Posted: Apr 11, 2007 08:55 PM

Tom,

I install the required 10" to get R-38. I do not do hybrid systems.

George

Thomas Kasper

Posted: Apr 11, 2007 08:55 PM

141 B was the blowing agent that was used prior to the 245 blowing agent. It was used until 12-04 when the price of foam materials skyrocketed.

Posted: Apr 12, 2007 12:47 AM

r-49 for energy star,,,doe recommendation for my cold climate zone...this is what our energy supplier wants for rebates...
r49@3.8/inch=12.8inches

physics is physics
r19 oc in an attic in our cold climate zone is not enough insulation to stop the convective flow of air...when hot meets cold,,,condensation occurs...

we cant tell someone that by buying the upgrade to foam that they are going to save bu-coo bucks and then apply 1/2 to 1/3 the neccessary r value and expect it to happen...
3x the performance at equal rvalues means apply to r 38 or better and then you may see the savings...

i too, do not apply the hybrid systems,,i let the competition have that business,,,
they like me,,,kinda,,,
foam-it!

Gerry Wagoner

Posted: Apr 13, 2007 10:15 AM

3/8" Of an inch across 16" framing (or is it 24") is excessive. Big time excessive!
A water-blown foam might have been better in this case.

141b was the standard blowing agent from April `93 to 2004. Prior to that it was the best foam ever: R-11 Freon foam.

Carry on,

olger

charles hogan

Posted: Apr 13, 2007 11:47 AM

The rafter spacing was 16 inches on center, I used to use water blown insulation and have never had any problems but I believed the salesman and the co. After asking them if there was any difference in installation between waterblown and their product they claimed no, now it's been 5 months and they still have not decided what they are going to do. Be careful with what they tell you.

Jason Kron

Posted: Apr 18, 2007 09:52 PM

I have seen one or two projects where the drywall ceiling has had a wavy finish a couple of months later. Some of my guys have did one of two things to keep this from happening the first is not to apply more then two inches ( acually they are trying to stick with 1.5") the second is putting down a tar paper to break the bond just the drywall not your structural memebers. In my opinion spray it a little thinner in first lift. Also I would be catious in spraying anyones foam thicker then 2" per lift. Or at least try to stay in that range give or take. I haven't seen anyone's that have really worked yet.

Timothy Sonney

Posted: Apr 19, 2007 12:58 AM

What we have done is no more than a 2" pass at a time, but also sprayed directly on the 2x8 or 2x10 over top and continue on to the next rafter cavity. This glues everything, and we have yet to see any issues.

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