# Spray Foam vs. Fiberglass, anyone done the math?



## hammerlane

What kind of costs are you getting for each?

Cost for fiberglass batt about $800??

Cost for spray foam about $6000??

Am I close?


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## AGWhitehouse

If you are planning on being alive long enough or are going to pass this house down to your kids, I'd stay away from spray foam unless you're doing a flash/batt method. When it comes time to renovate/upgrade that structure, spray foam will only add significant $$...You can't snake, you have to demo. So you'll pay more now and pay more later for a full foam install while flash/batt system will give you the sealing quality at a cheaper price and allow for renovations, etc. in the future.


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## vtboy51

I haven't even gotten that far, I just figured someone has already done some rough homework on the extra cost and what the heating cost benefits are.



hammerlane said:


> What kind of costs are you getting for each?
> 
> Cost for fiberglass batt about $800??
> 
> Cost for spray foam about $6000??
> 
> Am I close?


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## AGWhitehouse

The talk around the water cooler is that foam is, on average, 3x the cost of fiberglass...

There is more to consider on all this than just what type of insulation. Foam creates an air-tight seal that is not found in "traditionally" built homes. When you seal a house that tight, you now need to introduce mechanical ventilation to achieve the code required air changes and eliminate the risk of "sick house syndrome". These are costs that go above an beyond the additional insulation costs. Not taking into account the air change requirements, could lead to increased health risks and bouts of common illnesses due to airborn pathogens and debris that is not being filtered or exchanged.

The "traditional" home design accommodated the required air exchanges via leaky walls, windows, and doors. You turn on the kit/bath exhaust and it pulled in air through all the cracks. If you seal all those cracks and get nice tight doors/windows, you'll need to provide a source for fresh air intake.


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## jklingel

As stated, foam is expensive; over 3x what cellulose would have cost me. On top of that, the environmental impact is significant. If you want to use batts, I would suggest you consider leaving the fiberglass at the store, and get Roxul or one of the other batt products. FG is lowest on the list for overall R value. Too, consider a double stud wall with dense packed cellulose; one of the cheapest, $/R, and most environmentally positive ways to build. And DO build tight, then get an HRV.


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## AGWhitehouse

jklingel said:


> And DO build tight, then get an HRV.


Thanks for clarifying. I do agree and also recommend building tight and providing mechanical means of ventilation. The initial cost is quickly paid back through operational efficiency.


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## hammerlane

vtboy51 said:


> I just figured someone has already done some rough homework on the extra cost and what the heating cost benefits are.


Very hard to calculate with a degree of scientific certainty the cost benefit of when you would recoup the spray foam money.

To do this you would need two identical homes..well almost identical except one has spray foam and one has fiberglass insulation. Home would need to be situated in the same geographic orientation to take advantage of the sun's orientation.

Then you could calculate energy usage on each.


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## jklingel

AGWhitehouse said:


> Thanks for clarifying. I do agree and also recommend building tight and providing mechanical means of ventilation. The initial cost is quickly paid back through operational efficiency.


 Roger that. One thing that surprised me is how "cheap" it is to provide fresh air. Ignoring the trivial cost of the HRV laughing, it was only going to cost me a few hundred bucks in heat loss to operate it. I have no idea how that compares to what a leaky house costs you, but it made it clear that the HRV was really not a huge difference, and then you get the air moved properly, etc. I think the "build it tight, ventilate right" mantra is a good deal. I hope so, 'cause I'm gonna spend the $$ on one soon.....


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## AGWhitehouse

That is going to be the future of building when the new energy codes kick in. My uncle is building an "experiment house" and is purchasing HRV's he says have a 95% efficiency rating and only require 1A to operate. He said he was going to get me the cuts, but if he wasn't exagerating, those are some awesome performance specs. I can't imagine a leaky house is better than that considering the added benefit of actually filtered air exchanges.


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## NEFoamer

vtboy51 said:


> I haven't even gotten that far, I just figured someone has already done some rough homework on the extra cost and what the heating cost benefits are.


It's generally going to cost around 3x more for closed cell insulation, which is what you would want in vermont. I would NOT recommend flash and batt to anybody unless you're spraying at least 2" of closed cell, and at that point you might as well add the 3rd inch. The average payback is generally going to be around 7-10 years, but that is largely going to depend on your initial costs, heating costs, and future heating costs. You'll generally save 40%-50% on heating and cooling costs. You can usually also reduce the size of HVAC equipment, which can offset some of the cost of an HRV.


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## NEFoamer

Here is one case study, I'm sure you can find some more out there, hopefully more specific to your location. 

http://advancedinsulationla.com/casestudy.pdf


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## hammerlane

NEFoamer said:


> You'll generally save 40%-50% on heating and cooling costs.


I think that comment is such a crock and a common "talking point" in the window and insulation industry. I wonder how many companies would back that up with a guarantee to pay anything over a 3 year average of your gas bill in the winter.


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## hammerlane

NEFoamer said:


> Here is one case study, I'm sure you can find some more out there, hopefully more specific to your location.
> 
> http://advancedinsulationla.com/casestudy.pdf


 
Interesting reading


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## NEFoamer

hammerlane said:


> I think that comment is such a crock and a common "talking point" in the window and insulation industry. I wonder how many companies would back that up with a guarantee to pay anything over a 3 year average of your gas bill in the winter.


Feel free to google richard rue and energywise. Former nasa scientist who developed a program to do just that.


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## jklingel

AG: The future, no doubt about it. It will likely be in codes more and more, which means we'll have to do something to clean up the AIR in some places. That will be an interesting dilema; do we require ventilation in houses if the air outside the house is worse than inside? This is from Martin Holladay on greenbuildingadvisor.com, back in March of '12. "....this HRV has a sensible heat-recovery efficiency ranging from 64% at -13°F to 75% at 32°F at 49 cfm." See if your uncle has more data, like efficiency at what temps, etc. 95% would be incredible. NEFoamer: 40-50% over WHAT?


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## NEFoamer

What is the OP asking about?? Foam will perform 40-50% better than filterglass, that's for sure. Even during "perfect" installation it does not perform to rated R-value. Independent studies have said that typical installation results in around 25% loss of it's r-value. Foam certainly isn't the end all, be all, but it's a great product and the people who pay 3x more for it understand the value.


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## jklingel

NEFoamer said:


> Foam will perform 40-50% better than filterglass, that's for sure.


 Oh. OK. No doubt about foam being far superior to fg batts.


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## Windows on Wash

I just fell out of my chair...40-50% savings...?


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## AGWhitehouse

NEFoamer said:


> Here is one case study, I'm sure you can find some more out there, hopefully more specific to your location.
> 
> http://advancedinsulationla.com/casestudy.pdf


Looks like you didn't air seal the FG house. That report is like comparing the thermal efficiency of a storm door with gasketing and one without. Of course the leaky one will perform worse... But it's a perfect marketing tool for a spray foam contractor. "Here gullible home owner, see!"

Lets be clear though, foam will perform better than FG, but it won't perform THAT MUCH better if the FG home had been air sealed properly.

In 25 years, when the foam degrades, how will you repair it? You can't just take it out like FG, you have to chip/scrape/cut it out which = $$$. The sustainability of spray foams is deplorable...


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## anglii

Go with the spray foam!

Why?

1: You save up to 50% on heating and cooling costs over conventional insulation. Spray foam also creates an air barrier which cannot be achieved with batt insulation because of the seams. It doesn't lose R value in cold or wind las does any type of batt insulation, and when fiberglass in particular gets wet from any leaks its R value is rendered useless.

You can realize a real world profit of 74% per month on your utility bills over fiberglass insulation. The added cost to your mortgage of spray foam to an average home is about $20.80/mth. But this average home saves $88 on HVOC costs per month! Energy costs will only go up and in the 30 years of your mortgage the savings will only increase = money in your pocket and reducing your carbon footprint.

2: You save by being able to install smaller furnaces and air conditioning units.

3: You save by being able to use 2X4 studs instead of 2X6 studs during construction of your house.

4: You save by not needing interior and exterior vapor barrier during construction as spray foam is also a vapor barrier if 3 inches thick or more.

5: Installation costs of spray foam is also cheaper than fiberglass or other batt insulation.

Sources: 
http://www.ecologicinsulation.com/Questions.html
http://kinlar.ca/residential.aspx


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## anglii

Go with the spray foam!

Why?

1: You save up to 50% on heating and cooling costs over conventional insulation. Spray foam also creates an air barrier which cannot be achieved with batt insulation because of the seams. It doesn't lose R value in cold or wind las does any type of batt insulation, and when fiberglass in particular gets wet from any leaks its R value is rendered useless.

You can realize a real world profit of 74% per month on your utility bills over fiberglass insulation. The added cost to your mortgage of spray foam to an average home is about $20.80/mth. But this average home saves $88 on HVOC costs per month! Energy costs will only go up and in the 30 years of your mortgage the savings will only increase = money in your pocket and reducing your carbon footprint.

2: You save by being able to install smaller furnaces and air conditioning units.

3: You save by being able to use 2X4 studs instead of 2X6 studs during construction of your house.

4: You save by not needing interior and exterior vapor barrier during construction as spray foam is also a vapor barrier if 3 inches thick or more.

5: The labor cost of installing spray foam is also cheaper than fiberglass or other batt insulation.

Sources: 
http://www.ecologicinsulation.com/Questions.html
http://kinlar.ca/residential.aspx


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## framer52

here is a place to start in Vermont. the instructor with the answer is sourced for you

www.yestermorrow.org/instructors/view/96


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## jklingel

framer52 said:


> here is a place to start in Vermont. the instructor with the answer is sourced for you
> 
> www.yestermorrow.org/instructors/view/96


Riversong knows his stink, too. Very knowledgeable individual. He has contributed on a variety of forums and blogs as well, and is one of the builders who is focused on us minimizing our negative impact on the world.
Anglii: You must work for a foam company. I read a little hyperbole in your comments, and some are true no matter what you insulate w/ (needing smaller boiler, etc). If one really wants to build cheap ($/R), far less expensively than spray foam, be able to super-insulate, be environmentally friendly, ward off bugs and rodents, etc, then build a double stud wall w/ dense packed cellulose. Spray foam has its place, but not in my place; way too expensive and torturous to the environment. To me, its a last-resort product to be used sparingly. Good stuff, just don't get carried away w/ it.


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## anglii

AGWhitehouse said:


> Lets be clear though, foam will perform better than FG, but it won't perform THAT MUCH better if the FG home had been air sealed properly. . .
> 
> In 25 years, when the foam degrades, how will you repair it? You can't just take it out like FG, you have to chip/scrape/cut it out which = $$$. The sustainability of spray foams is deplorable...


.

Studies show you cannot achieve the same kind of air seal with batt insulation and the real world R-value of batt is decreased depending on the environmental temperature and wind speed. I.E._ "R-13 fiberglass batt in the presence of a 10 mile per hour breeze diminishes the insulating power of a batt to an R-5".
_ 
Where did you get your information that spray foam degrades? Because if parts A and B are mixed properly it is inert and does not degrade after it has cured (in about 4 hours).

But you do have to get an experienced installer to make sure it cures properly. Some risks include allergy to the petrochemicals used. But staying away from the building site until it's cured and looking at soy based options would prevent sensitization.

http://www.greenbuildingadvisor.com...spray-foam-insulation-out-gas-poisonous-fumes


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## NEFoamer

AGWhitehouse said:


> Looks like you didn't air seal the FG house. That report is like comparing the thermal efficiency of a storm door with gasketing and one without. Of course the leaky one will perform worse... But it's a perfect marketing tool for a spray foam contractor. "Here gullible home owner, see!"
> 
> Lets be clear though, foam will perform better than FG, but it won't perform THAT MUCH better if the FG home had been air sealed properly.
> 
> In 25 years, when the foam degrades, how will you repair it? You can't just take it out like FG, you have to chip/scrape/cut it out which = $$$. The sustainability of spray foams is deplorable...


Deplorable??? Please. Show me some examples of closed cell spray polyurethane foam degrading in an interior wall. Spray foam has been around since the 50's so I'm sure you can find plenty of examples. The only thing that will deteriorate foam is direct exposure to sunlight. 

As far as the case study goes, I didn't forget to do anything as this was done by the Habitat for Humanity. I don't know what was or wasn't done as far as air sealing goes. You can use all the caulk you want and spray foam will still do a better job. Hence the fact tens of thousands of people use it every year.


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## framer52

NEFoamer said:


> Deplorable??? Please. Show me some examples of closed cell spray polyurethane foam degrading in an interior wall. Spray foam has been around since the 50's so I'm sure you can find plenty of examples. The only thing that will deteriorate foam is direct exposure to sunlight.
> 
> As far as the case study goes, I didn't forget to do anything as this was done by the Habitat for Humanity. I don't know what was or wasn't done as far as air sealing goes. You can use all the caulk you want and spray foam will still do a better job. Hence the fact tens of thousands of people use it every year.



Come visit my house I will show you foam disintegration after use in my walls since the 70's.

I am wondering if they have ever come out with a true R value for foam as off gassing continues for years after installation.

Now my private concerns with site foam blowing has to do with the mixing on site without precise computer control of the mixing agents which will give foam site blowing different than factory foam.


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## AGWhitehouse

Yes...Deplorable...current foams are made from oil. Being that oil IS finite and being consumed a mind boggling rate, it's safe to say an end WILL eventually come. The essence of sustainability is a product that is "natural" and therefore can be found readily available through the existence of earth (barring no apacolypse of course).

And thank you framer for the rea-world example. Foam degrades people...sorry to burst the "cure all" sentiment. Most rigid foam manufacturer's don't warranty their products for more than 20 years. And most pro-rate the R-value to accommodate the degredation over the lifetime. Polyiso, when blown, is around R-7+ an inch, but they advertise around R-6.5 an inch to account from degredation.


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## AGWhitehouse

See next post


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## AGWhitehouse

anglii said:


> .Where did you get your information that spray foam degrades?


Here's one manufacturer noting the degredation of their polyiso foam: http://www.hpanels.com/images/stories/pdfs/lit_prod_color/english/H-Shield.pdf

Notice on the Thermal values chart the asterisk next to "LTTR R VALUE" and the sentence below. The "weighted average" is the technical jargon to account for foam degredation over a 15 year period. Essentially if the foam is an R-7.5 when new and assuming constant degredation it would be approx. R-4.6 after 15 years making the average the R-6.0 as depicted.


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## NEFoamer

My bad I thought we were talking about something other than an exterior polyiso rigid board insulating panels....oh wait. So your arguement is that foam MAY not last for eternity? What building materials will?? Should we reconsider using concrete? Wood rots eventually.... 

As far degrading in interior walls i've never heard of such a thing. I'd be willing to bet however that it was installation issue and ol' father time had little to do with it.

There have been great strides in the industry and it continues to become more enviromentally friendly and sustainable(soybased).


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## jklingel

A "small" problem I have read about w/ foam, that can not be cured (no pun intended), is spraying only between studs/rafters instead of a continuous layer. Wood shrinks a tad, and then you get a crack. So, were I to use spray foam, I'd ensure that there was a continuous layer over everything, just in case this cracking really does happen. I hope the spray foam industry continues to evolve, too.


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## framer52

I am trying to figure out how to answer your post.

Foam will and has degraded r value over time. Does the foam itself? sometimes.....


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## framer52

if you think soy based foam is great, spend a little time and read the MSDS.

Trust me, a lot of chemicals other than soy.....


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## Windows on Wash

AGWhitehouse said:


> Yes...Deplorable...current foams are made from oil. Being that oil IS finite and being consumed a mind boggling rate, it's safe to say an end WILL eventually come. The essence of sustainability is a product that is "natural" and therefore can be found readily available through the existence of earth (barring no apacolypse of course).
> 
> And thank you framer for the rea-world example. Foam degrades people...sorry to burst the "cure all" sentiment. Most rigid foam manufacturer's don't warranty their products for more than 20 years. And most pro-rate the R-value to accommodate the degredation over the lifetime. Polyiso, when blown, is around R-7+ an inch, but they advertise around R-6.5 an inch to account from degredation.


+1

Foams are worthwhile consideration but they are all oil based and you get nearly every bit of performance out of a properly designed and sealed wall assembly.


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## AGWhitehouse

framer52 said:


> I am trying to figure out how to answer your post.


It doesn't seem to be worth the time, couple the handle with the logic and you're better off spending your time elsewhere...spraying stud/rafter bays is becoming increasingly shunned as the economic and secondary (refurbishing, remodeling) effects are become weighty enough to persuade most to alternative methods of insulation.

And to add to JK's comment about the wood shrinkage. This is real and closed cell foams are so rigid that they have troubles accomodating it. My uncle faced it himself a few months ago. It's similar to filling stud bays with grout and saying it won't crack...

Anywho...enjoy, I'll be unsubscribing from this post...


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## anglii

AGWhitehouse said:


> Here's one manufacturer noting the degredation of their polyiso foam: http://www.hpanels.com/images/stories/pdfs/lit_prod_color/english/H-Shield.pdf
> 
> Notice on the Thermal values chart the asterisk next to "LTTR R VALUE" and the sentence below. The "weighted average" is the technical jargon to account for foam degredation over a 15 year period. Essentially if the foam is an R-7.5 when new and assuming constant degredation it would be approx. R-4.6 after 15 years making the average the R-6.0 as depicted.



AG you're comparing apples to oranges. You link to a rigid insulation product not spray foam. You wouldn't get the same seal with rigid sheets as with spray foam. Also, the "weighted average" takes other components of a wall into account such as framing and the effect of environmental temperature and wind on R-value. Obviously the R-value of a product with seams such as rigid insulation would fluctuate more over 15 years than a spray foam not necessarily proof of degradation.


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## NEFoamer

anglii said:


> AG you're comparing apples to oranges. You link to a rigid insulation product not spray foam. You wouldn't get the same seal with rigid sheets as with spray foam. Also, the "weighted average" takes other components of a wall into account such as framing and the effect of environmental temperature and wind on R-value. Obviously the R-value of a product with seams such as rigid insulation would fluctuate more over 15 years than a spray foam not necessarily proof of degradation.


Try not to confuse him more than he already is.


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## NEFoamer

Windows on Wash said:


> +1
> 
> Foams are worthwhile consideration but they are all oil based and you get nearly every bit of performance out of a properly designed and sealed wall assembly.


I understand everyone's concern with foam being oil based. What the heck isn't though? I think there are much bigger fish to fry as far that arguement goes, and a well insulated, air sealed home like spray foam provides will save more over time than it uses.


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## NEFoamer

framer52 said:


> if you think soy based foam is great, spend a little time and read the MSDS.
> 
> Trust me, a lot of chemicals other than soy.....


I didn't say it was great, just a step in the right direction.


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## NEFoamer

jklingel said:


> A "small" problem I have read about w/ foam, that can not be cured (no pun intended), is spraying only between studs/rafters instead of a continuous layer. Wood shrinks a tad, and then you get a crack. So, were I to use spray foam, I'd ensure that there was a continuous layer over everything, just in case this cracking really does happen. I hope the spray foam industry continues to evolve, too.


That is possible. I haven't seen it personally. I had to remove drywall in my basement due to a window leak and I didn't see any signs cracking along the studs, though this was only 2 years after application. I would suspect any cracking would be pretty minimal. A much more common culprit of foam pulling from the studs is usually an applicator error by either spraying on too cold of substrate or spraying the foam at the wrong temp. Even a closed cell rigid foam has a some flex to it, unlike, say grout for example...:whistling2:


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## jklingel

NEFoamer said:


> I understand everyone's concern with foam being oil based. What the heck isn't though? I think there are much bigger fish to fry as far that arguement goes, and a well insulated, air sealed home like spray foam provides will save more over time than it uses.


 For one, cellulose is not oil based, but it ain't free of embodied energy, either; just better so. Foam, done well, will seal and insulate enough (for most locations), and it sure will therefor save energy. It is just that, IMO, it is not the best sole insulation in a wall. You can air seal down to Zipsville with plywood, airtight drywall approach, etc, so the argument that foam seals, though true enough, is not a great shout to use it just for that. Places that are nearly inaccessible or extremely tedious to work on properly? Spray foam 'em and be gone. Best luck to all; choosing "the best" ain't always straight forward.


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## Thunder Chicken

I used spray foam for a renovation a few years ago. We have a cottage with a membrane roof on the front that tends to get hot in summer. The rafters in that area were pretty shallow, not deep enough to put enough fiberglass in to keep things cool. So we shelled out for spray foam for that section of the ceiling, in order to stuff as much R into the rafters as possible. It does a nice job of keeping that area cool in the summer. I don't know what that saves energy-wise as I did it my first summer here, but it is comfortable. It was pricey, but I only did one 18' by 8' ceiling so it wasn't a big deal.

I wouldn't pay to do the whole house with it, but in tight spots or places with irregular cavities (irregular spaced joists in the floor, for example) it is not a bad way to go. The R value is nice but the real savings comes from ease of installation in these areas. Insulating a 70 year old crawlspace otherwise would be a real PITA.


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## FrancisABoyd

I used this site and they have a expanding foam insulation vs traditional insulation savings calculator...it might help. I like sprayfoam. If you follow the instructions it's really quite easy to do yourself. It's expensive but worth it in the long run. We redid our roof right before we inuslated and the amount of mold that was in the old blown cellulose was sick! One of the big selling features us, the expanding foam we chose to go with was that it is anitmicrobial. 
Good luck!!


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## princelake

i've just been skimming through this topic. in the past year or so at we we've done a handful of home that have spray foam. i find it horrible stuff and i'd definitley use batt insulation on my own home. i work in the insurance industry and i have been hearing rumours that the next biggest thing in 10years or so is mold because the wood in new homes shrink so much that there are now gaps and cracks and after so many years ppl open walls to do renos. working with it suckksss, if the guys missed a spots shaving it down good luck putting drywall on and our nail pops have increased alot! and what about the spray foam the window and door guy uses, its not a spray foam thats rated as a vapour barrier. when you put in batt insulation you know its there and you know its good. the only positive thing i see with spray foam is the speed of it and it gets into hard to reach places. i'd batt my walls and hard to reach places like between my floor joists i'd spray to save time.


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## concretemasonry

You cannot get an "exact" analysis of insulation based on the so-called "R-values" that are just short term lab tests (usually an hour or so) to measure the resistance to heat flow of the material itself and that does not accurately the insulation value of a wall. Just used very well by a cute pink feline with Henry Mancini music in the background.

The "R-value" of a material filling a void is very close to being a factitious number for advertising and not real life. Even ASHRE recognizes this effect.

The other factor is the ability of some insulation materials that supposedly do not absorb moisture but hold the moisture and feed mold growth on wood framing. I saw hundreds of those situations after Katrina when homes had to be re-done several times within months.

The newer chemicals in some loose fill can eliminate the mold, moisture and fire problems.

Dick


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## 6273909

*Fiberglass is better!*

I have fiberglass insulation in my 3500 square foot, all electric, home. My electric bill is less than my neighbors smaller home that has foam insulation. I have r-21 in the 2x6 walls and two layers of r30 in the attic. I spent 4k on insulation an my neighbor spent 16k. My last electric bill was $88.00. We have four people and two electric hot water heaters. My high winter bill was $220 and my high summer bill was $155. We are in South Alabama. 

I have double insulated low-e non-filled windows, 34 of them, and 9 exterior doors.


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## Windows on Wash

Poorly installed foam is going to get outperformed by properly installed fiberglass (assuming there is an attention to the envelope).

Spray foam's primary benefit is the combination of air sealant and insulation. 

If you are using it just as an insulation, it is expensive and probably wasteful.


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## cocobolo

OK, read the entire thread, and while I don't have much to add a lot of what has been said in here isn't terribly accurate.

One thing I can tell you from experience is this. Many years ago our trusty Canadian Government partially sponsored the installation of UFFI (Urea Formaldehyde Foam Insulation). It was intended to go in to older homes which had either no insulation at all, or possibly the aluminum foil that used to be popular back in the day.

When installed correctly, it only did a so-so job - and I will say why in a second. When installed poorly it was totally useless. 

Not only that, but it became dangerous in the event that any moisture got into a UFFI'd cavity.

Subsequent to getting many complaints about UFFI, our trusty Canadian Government (federal) did an about face and then had to sponsor part of the cost for removal of this self same product. I was one of a relatively small handful of people who got a license to remove UFFI. Let me tell you, it was NOT a fun job.

A homeowner could take the UFFI course and be granted a license to remove the UFFI from his own home and thus take advantage of the $5,000 grant for removal. But he could do no others. The course was intended for trades people, typically carpenters.

What I found was borderline disgraceful. It was always easy to tell when the installer knew what he was doing, because the cavities would be correctly filled. When they had no clue, well, some of the messes we uncovered were downright criminal. It was one of those times in our past construction history that every crook wanted to get in on the act and make a quick buck. OK, maybe that's stretching it a bit, but there were more lousy installs than good ones.

Here's what happens with the UFFI installs, and remember this is from personal experience.

I do not ever remember opening any cavity and seeing the whole thing 100% filled. The foam would invariably pull away from one or both sides of the studs, or it would be cracked into large pieces. Please be sure to understand that this had nothing at all to do with any stud shrinkage, as these houses were likely 30-40-50 years old before the UFFI install. The cavities would have been as dry as a bone. A very old bone at that!

So, from observation, I can say that this particular foam definitely shrank once it dried out.

It also caused some serious health problems if a cavity ever got damp or wet. I did find one such case in Trail, where the husband's bedroom was right next to a UFFI'd wall and the stucco outside had a massive crack down the entire wall. He got sick shortly after the install, and neither he nor his nurse wife could figure out what was wrong. His first night in that same room after we pulled the foam out eliminated the trouble, just like that. That was the only case of illness that I encountered, but many others were reported to CMHC as the removals took place.

Whether or not the current batch of foams act any better, I really do not know. But there has been a lot of chat in this thread about lumber shrinkage. If you use KD lumber, surely that shrinkage must be very small. Why could a foam not adhere to the studs in such a case? Is there no flexibility in the newer foams?

I'm in the process of designing a net zero energy home and I came here looking for help with insulation, particularly cellulose. I will post a new question about that.


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## jklingel

..."I came here looking for help with insulation, particularly cellulose." •• That's The Stuff!


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## parts

NEFoamer said:


> Here is one case study, I'm sure you can find some more out there, hopefully more specific to your location.
> 
> http://advancedinsulationla.com/casestudy.pdf


 I have worked on more than a few houses for Habitat and I don't think comparing a house professionally done by a foam company to one done most likely by volunteers makes a valid case study.


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## Windows on Wash

parts said:


> I have worked on more than a few houses for Habitat and I don't think comparing a house professionally done by a foam company to one done most likely by volunteers makes a valid case study.


+1

Insulation is probably one of the most improperly deployed items in home construction so I would tend to agree with you wholeheartedly.


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