what R value would you insulate to...

[Jaguar Fan]

If you were building your current house from scratch, what R Value would you insulate to? Would you use fiberglass batting, blown-in cellulose, expanding foam, etc?

What R value would you put in the attic versus walls?

 

[65Stang]

Some of this is dicated by code. For me, it would be R38 in ceiling, blow-in is cheaper usually, and R30 batt in the walls.

 

[twostory]

In Georgia, R13/R19 fiberglass in the walls, R38 in the attic (blown cellulose). This is what I did in my garage. I also used Tyvek, and was careful to tape the seams & seal all windows/doors.

Now if money was unlimited, I would pay for the best spray foam out there. It seals better & has more R value per inch.

 

[rickairmedic]

I agree if money wasnt an issue I would have the whole house done with Spray foam and be done with it.

Rick

 

[mvp dad]

If money is the issue than spray foam IS the way to go!! If you look at up front costs vs. energy savings foam pays for itself quickly 5 yrs +/-. I am in the HVAC industry in GA. I see lots of homes daily who suffer due to poor insulation and poor building practices. The foam insulation will solve those problems plus increase comfort.

 

[jtillery]

Like the others have said, if you are pulling a permit for the work their may be code requirements that you need to comply with.

Your location will change the insulation requirements drastically. One of the best things to do in my opinion, is google "insulation savings calculator". You need to input a bunch of information, location, building size, construction type, type of heating and cooling, insulation cost, gas/propane/electric cost (whichever is applicable). That will show you how much money you will save by insulating or adding additional insulation. Most people would be surprised that adding additional insulation has a very long payback time in alot of circumstances.

For my shop, I settled on R-11 fiberglass batts for both the walls and ceillings. I am in Cleveland, OH. According to the calculators, I will save 1.2 times the cost of my insulation each year. If I would have gone to R-13 in the walls and R-30 or R-38 in the ceiling (which is typically recommended for me area) it would have taken 30 years to payback the additional cost.

One thing that often gets overlook (I sure did), is how much more enjoyable an insulated space is. My shop is much quieter now, and overall the temperature is alot more consistent. It made a huge difference in how I will enjoy the space.

 

[walrus]

In Maine, I'd cut and fit seconds foam into a 2 by 6 wall, laying a sheet of 1 inch over the studs for r -42 in the walls. Depending on the ceiling I'd go for at least R-54, . It makes for a comfortable house, quiet and no drafts. I know from experience

 

[Dragster Racer]

How thick are R30 batts for the walls? 6" is R19 I think.

 

[IDASHO]

There are a few custom builders up here in Idaho building homes with 2x10 walls, to fit high density R38

And what do you put in the ceiling if you insulate the walls with R38??

R50 of course!

 

[IDASHO]

How thick are R30 batts for the walls? 6" is R19 I think.

standard is 9.5

"Cathedral", also sometimes referred to as high density is 8.25

 

[TRTOOLSUPPLY]

I would agree that spray foam is the way to go.They had problems with it years ago;bowed walls,windows that won't open,etc.The new foam works perfect.I know "THE SPRAY FOAM GUY'S" ,that work locally ,they have a great rep.TR TOOL SUPPLY(Richard)

 

[mmhouse]

I lived in Fairbanks, Alaska for a number of years. Custom builders got very creative with insulation techniques there. In colder climates it's not only the R-value but also the vapor barrier, sealing against air infiltration and providing thermal breaks (avoiding thermal bridging which allows heat to travel through the studs from inside to outside). Interesting stuff....particularly where it can get to and stay at -50 degrees fahrenheit for days at a time.

 

[rsanter]

if money was no object I would use spray foam in the walls, a layer of faom around the whole structure and use 2x6 perimeter walls.
I would be shooting for R40-R50 all around.

if building from scratch I would really look at ICF construction and SIP pannels for the roof

bob

 

[Jaguar Fan]

if money was no object I would use spray foam in the walls, a layer of faom around the whole structure and use 2x6 perimeter walls.
I would be shooting for R40-R50 all around.

if building from scratch I would really look at ICF construction and SIP pannels for the roof

bob

Thanks for the tip on SIP. I hadn't thought of that. I'll have to research it. In the desert of Las Vegas, it only gets down to about 20 degrees F or so in the winter, but up to 115 to 120 degrees F in the summer. Its the summer that is more of the concern than the winter.

Thanks!

 

[rsanter]

what kind of structure are you going to build?
if its a pole type building or a steel framed building then you can also look at the KINGSPAN insulated panels for the roof and the sides
for the roof you will also want to install something that is a 'coolroof'
we have an ICF building here on site where I work that has the SIP pannels for the roof with a white standing seam metal roof. that building always stays nice even during the summer.
we also have a small warehouse building that has SIP walls and ceiling and again has a light colored standing seam metal roof. this building has no AC and no swamp coolers and it stays nice all summer long

bob

 

[nate379]

R35-40 in the walls and R45-50 in the ceiling.

 

[hetkind]

I am about to start construction on a pole barn...conventional R-13 4" insulation batts on all walls and ceiling, with heat coming from a pot bellied stove. I suspect when I finish out the upper level, additional roof insulation will be installed.

Howard

 

[Dragster Racer]

I'm going to stick my neck out with an ignorant question: When did 9.5" walls become standard, and how in the world do you get R35-40 in the walls without foam? Most houses I see are 2X6 construction. Doesn't that leave a 6"cavity to fill? That would be R19? To double that with roll insulation, that would be a 12" cavity? What do the window casings look like? Unless we are talking about foam, I am lost. And if we are talking foam, that must be one expensive job for a house.

 

[brad d]

When my dad built his house it had two 2x4 walls spaced apart the whole wall was 16" thick...

a bit over kill but i bet it would be cheaper than foam.. I did 2x6 with 1.5" of SM foam

 

[overkill 19]

Around home some people have been doing the 2x6 or 2x8 plate with 2x4 studs, then weaving the batts so you don't get any heat loss through the studs. Way cheaper around here to do as wood is cheaper than Foam.

I have a 60 year old house, made of Fir. When I renovated I was changing out all my windows. I went with 1.5 Styrofoam and with my 2x4 walls it worked out perfect with buying 2x6 framed windows. The width matches perfect for your trim on the inside.

The garage I'm building this summer will be 2x8 walls with 2x4 studs staggered. No foam due to cost. 1.5 shiplap foam is $19 for 2x8 foot sheet. I work for Dow Chem. and we used to get a employee discount but that went south fast with our economy

 

[OldCarGuy]

My house was constructed in 1976. And all the walls have spray polyurethane foam. That seems to be doing an excellent job of insulating the walls. But the ceilings has about 8" to 9" of settled blown in cellulose insulation. That I'm not so sure of its' performance. The upstairs is always colder than the downstairs in the winter. And opposite when the air conditioning is running in the summer.

To hopefully solve this problem. I spent my past Sunday afternoon by adding 2,500 square feet of 12” thick un-faced Owen Corning's R-38 fiberglass insulation. To the house and attached garage attics..

 

[overkill 19]

My house was constructed in 1976. And all the walls have spray polyurethane foam. That seems to be doing an excellent job of insulating the walls. But the ceilings has about 8" to 9" of settled blown in cellulose insulation. That I'm not so sure of its' performance. The upstairs is always colder than the downstairs in the winter. And opposite when the air conditioning is running in the summer.

To hopefully solve this problem. I spent my past Sunday afternoon by adding 2,500 square feet of 12” thick un-faced Owen Corning's R-38 fiberglass insulation. To the house and attached garage attics..

My house is the same as far as the upstairs down stairs hot cold thing but I think mine is due more to poor return air duct work or lack of.

 

[hidollartoys]

I think if the building is located in an area where there is more cooling days than heating days such as Vegas then the focus would be the ceiling/roof insulation. This would be coupled with very agressive attic venting and wide overhangs on the structure to shade the side walls. There is a law of deminishing returns for any level of insulation above what is "traditionally" done in any geographic area. You should discuss this with the local utility companies and be somewhat cautious when deeling with local insulation contractors. Utility companys have very realistic calcs for this sort of thing.