Foam or fiber insulation

[JSPANIER]

So I'm building on and got a quote on urethane foam vs. fiberglass. The foam was nearly double. Anyone else ever made the comparison? The price difference doesn't seem worth it. I figure the energy payoff is a decade out but that's just a guess.

 

[AdvantageR1]

My friends are building a house right now. They are trying for a four or five star energy rating. After all of their research they decided that the cost/benefit did not outweigh the cost/benefit of the spray insulation that is not foam. They are doing 6" exterior walls.

 

[JSPANIER]

I thought about doing the exterior walls in foam but using fiber between the attic and living spaces.

 

[ssgrock3]

spray foam is worth the difference. don't know what vender you are using or what size of home you are building, but for a larger home, it is well worth the money. Seals them up tight, less noise, less dusting. Contact Agile foam, he does a great job. You will also want to ensure you properly size your ac unit for foam. btw, we were calculating a ROI of about 4.5 years. With a full foam envelope, your attic can be nearly the same temp as your inner home.

 

[JSPANIER]

I never thought about the AC unit. The room is big and has a dedicated 2.5 ton unit. Should I reduce a 1/2 ton?

 

[ahamay6]

We are about to build and our builder actually discouraged the use of foam because it required a $3k dehydrater unit ith the hvac. He stated that full foam would result in mold problems without it due to a regular hvac not having the neccessary water removal ability. He reccomends cellulose over fiber because it has higher r value and they dont have the settling issues that they used to with it.

 

[Hampton]

You need to have a heat load calculation done to determine how much heating and cooling capacity you need.

 

[doctorjj]

We are about to build and our builder actually discouraged the use of foam because it required a $3k dehydrater unit ith the hvac. He stated that full foam would result in mold problems without it due to a regular hvac not having the neccessary water removal ability. He reccomends cellulose over fiber because it has higher r value and they dont have the settling issues that they used to with it.

I would run from any builder who discouraged the use of foam.

 

[4play]

I cant speak for the price but I went through a few open houses by the same builder in the same area and some were foam and some were fiber. The foam houses were significantly cooler, especially in the garages and attics. The houses with foam were cooler in the attic than the fiber homes were in the garage. I would say if you really planned on it being your last home it would probably be worth doing the foam. I would want the foam and might even consider ducting the garage for HVAC.

 

[10Seconds]

We are about to build and our builder actually discouraged the use of foam because it required a $3k dehydrater unit ith the hvac. He stated that full foam would result in mold problems without it due to a regular hvac not having the neccessary water removal ability. He reccomends cellulose over fiber because it has higher r value and they dont have the settling issues that they used to with it.

This could not be more false! I am a NAHB Certified Green Building Professional and can say with certainty that your builder has no clue what he is talking about.

I can give you a ton on info on this but in a nutshell, foam is the way to go if you can afford the upfront costs. It has a payback period of 3-5 yrs depending on the project.

For a fee, you can also get your home certified too. We did this on a home just under 5000 sq ft and got a guarantee that the utility bills would not exceed $160 per month for 2 yrs or else they would pay it. Guess what - they never exceeded that amount.

Foam insulation, properly installed, is the best thing you can do energy wise for your new home.

Period.