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Larry iverson
Posted: Jun 08, 2011 07:46 PM
debating on removal
hi first time user to website
I live in a 1970s era tri level home in northern ca I personally removed all attic insulation and sealed all vent to drywall gaps,and every sheetrock seam,all wall plate holes I had the ointention of having open cell sprayed on ceiling about 6 inch and then adding cellouse on top.In addition all duct work was replaced with r8 flex duct.the lower level is raised.

what i did was change my mind because of the salesman.i changed at the last minute and had them spray the under side of roof deck with open cell I also had the lower raised level sprayed under the floor decking thus supposedley creating a envelope.i have not installed any barrier on the foam.

the question is i am not exactly happy with the results and I am debating removing it. maybe you have some suggestions before i get carried away. the a/c runs all the time and the furance runs all the time to maintain temp if i shut it off it gets hot in the summer and cold in the winter the home was more effecient before I did this i have all other details but wanted to start somewhere.i do believe in the concept of the envelope and realize that i do not have a true envelope. thanks so much larry
SprayFoamSupply.com
Posted: Jun 09, 2011 07:43 AM
In my opinion, 6" of open cell foam is not enough to give you the performance you are looking for. What are is the required Rvalue in your area for under the roof deck? How consistent is the surface of the foam? Do you have many high and low spots? If there are alot of low spots, how thick is the foam in them? Are there alot of voids in the foam? Were the gable end walls sprayed and all vents to the outside closed off? With ductwork in the attic, you did the right thing spraying the underside of the roof to create a conditioned space for your ductwork.

George
mason
Posted: Jun 09, 2011 10:04 AM
I say ditto to what George suggested. You do need to fill all the cracks and crevices to seal the space and provide a minimum amount of foam to be energy efficient. 6 inches of open cell foam only provides an R value of 21-24. You would want more than that in your area. Check out the kneewall areas to see if they are sealed properly and take some foam samples to check for voids and gaps in the foam. You might want to use an infra-red camera to assist your investigation.
Larry iverson
Posted: Jun 09, 2011 12:19 PM
good morning
thnak you for the replies.
all roof vents were close of with a solid foam board first and then sprayed over,all knee walls were sprayed to the same consistancy. I did have the sprayer come out an dhe did do a infared test an dfound a couple small places on the knee wall near the ceiling.the foam appears to me a mostly consistent but not like snow untouched.is it feasable to spray closed cell over the open cell in the attic to create the barrier and to make it as consistent as possible?
Iam not sure what rvalue is required to be on the roof but I believe its r38 on ceiling I will check on the roof the area sees snow once every 30 years and freezing temps maybe 10 nights per year
Posted: Jun 10, 2011 04:12 AM
consider..load calcs..
you went from the flat lid(insulatin on the deck) assembly to the conditioned lid assembly,,,
you added xxx amount of cubic ft of now passively conditioned space to the load required by your hvac system...
you probably removed twice as much "r" of filterglass or other off the deck and got sold half as much "r" of foam on the conditined lid assembly...less "r",,more load,,,run forestt run,,,
not sure of your zone,,3 or 4,,nor of what your attic assembly's call for,,but thats where this hillbilly foamer would go,,,r40 oc on the deck and we wouldnt be having this dialoge,,you would be happy as a bug on grape vine,,

good luck
dude
John Shockney
Posted: Jun 12, 2011 05:48 PM
dude,

I agree with most of what you are saying, but it is not the added cubic feet of space that adds to the heating or cooling load! It is the 20 to 30% added square footage of surface that is exposed to the outside, also the insulation (on the underside of the roof) doesn’t have the advantage of a dead air space above it protecting it from the direct effects of wind washing and heat transfer due to conduction to water during rain.

And as dude said if R-38 to R-40 had been installed this system would work better than any insulation system installed on the ceiling, because with the foam on the underside of the roof the attic becomes an additional dead air space adding to the insulation system and providing additional thermo mass.

I thought that bug was in a rug

Airpro
Larry iverson
Posted: Jun 12, 2011 06:17 PM
thanks for the constructive criticism
what I am looking for is what to do now. I am a homeowner looking for a solution to what a contractor did any other comments on what should have been done are mute at this point.Iam faced with adding more or removing it I guess
thanks Larry
Posted: Jun 12, 2011 08:50 PM
airpro...
spanx,,i always count on you for a way for this hillbilly foamer to get a grasp of this schtuff plays,,,can you send me a copy of manual j perty please???
but conceptually,,,
luvyouman,,,
dude
Larry iverson
Posted: Jun 12, 2011 09:09 PM
mmmm. foam dude are u saying i installed this foam and now im asking for help.
im sorry but your wrong i guess i asked for help from the wrong place. my question was sincere I did not spray on my own or even try too. sorry to waste evweryones time.
Larry iverson
Posted: Jun 12, 2011 09:09 PM
mmmm. foam dude are u saying i installed this foam and now im asking for help.
im sorry but your wrong i guess i asked for help from the wrong place. my question was sincere I did not spray on my own or even try too. sorry to waste evweryones time.
John Shockney
Posted: Jun 12, 2011 11:35 PM
Hi Larry

I’m sorry that dude and I took your thread in a different direction we have been debating this issue of spraying the ceiling or spraying the underside of the roof for some time here at sprayfoammagazine.com.

But you are in the same boat as other home owners out there that were over sold on the performance of spray foam and removed insulation that had higher R-value than the foam it was replaced with.

I can tell you that foam of a given R-value will perform almost twice as well as the same R-value of fiberglass at extreme temps, but compares almost the same as cellulose. This is mostly due to the air movement inside of the fiberglass caused by convection air currents.

The bottom line is that you probably need more insulation and the best thing would be to spray more foam to the roof deck here in Indiana we recommend 8-10 inches of open cell foam that puts you at the R-31 to 38. You could also add insulation to the ceiling but there is a danger of condensation forming on the underside of the foam depending on you climate and that I can’t advise you on as I don’t know all of your climate conditions.

I hope this is more helpful

Airpro
Posted: Jun 14, 2011 05:39 AM
larry,,no man,,my appologies,,
you did what you were to do here,,
posted your question into the world
for some real advice,,,and you got it..
thats the beauty of spf.com,,,
,,,and the smiles are free,,, :)
see,,,i am a blohard here on spf.com,,,
i like to beal to provoke dialoge,,
to make peeps think,,,hopefully,,
sometimes the thread will get off on a twist,,,
which is kinda where it went here,,

btw:it was clear by your initial post you werent a diy'er,,,and i for one took your question serious,,,and my response was serious as well,,,
again: forgive me,,,you did not waste my time and i invite you to post more,,,

hopefully you got some good advice from the posts???

peace
dude

(just re-read my original post,,,"you" is a figure of speach,,,re-read my other posts,,,i am the "hillbilly foamer" refered to,,do a search,,gawd dont be sensitive,,,we really dont have snipers here unless your a troll,,rofl)
Larry iverson
Posted: Jun 14, 2011 07:34 AM
foamdude
No problem I can appreciate a sense of humor.
I have had a tough year,My Daughter passed away in January so Im not all together and was reading more into than I should have, I just wanted to get to the point.I have gotten some good advice i believe I either need more foam or need to find some serious leaks or both
thanks again for the advice I do appreciate you taking the time to help and while Im not your customer I do appreciate it from a consumer point of view.
Have a nice day
Larry
mason
Posted: Jun 15, 2011 12:46 PM
Give me a call if you would like to discuss. The first 30 minutes are free. I don't sell or install the foam and can provide an independent view and analysis of the situration.

571-239-5221. I am traveling today but am availble tomorrow.
John Shockney
Posted: Jun 16, 2011 09:52 AM
dude,

I have never used "manual J" because my training wasn't through the ACCA most of my heat loss/gain training materal was provided by Copland compressors and I still use some of thouse figures.

But if you design a system today based solely on enough heating or cooling for the coldest or hottest days as manual J will provide. And if you install the system that it tells you to you will have too large of a heating or cooling system during mild weather so most of the systems that we are installing are multi-stage with electronic t-stats to maximize comfort and still provide enough heating or cooling in the extremes.
Also by using 2stage, 3 stage or variable speed equipment it is very hard to oversize a system, and they work great!!

Airpro

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