Spray foam insulation thoughts/advice for new addition?

[Sharpshooter3]

Dose anybody have experience with closed cell spray foam insulation in exterior walls on a house? I’m thinking this is the way I want to go on our new house addition due to the higher R value it provides. Just wondering from those that have experience with it; how thick did you have it applied? (I have 2x6 walls) How is it for noise transmission? (Is if fairly quite or can you hear everything going on outside) Any other wisdom on the subject would be appreciated. For reference I live in zone 5.

 

[hlee]

All I know about spray foam is that it does a really good job of “recoring” an archery target. And, <18” or so will stop a broad head tipped arrow, fired at >300 FPS, from 20 yards.

 

[Mike 556]

Its not the R value, its the elimination of air infiltration that is spray foams greatest asset. Do a flash and batt, 2" of closed cell foam applied to the walls with 3 1/2" batt insulation. Best of both worlds. We do that to most of the homes we build, coupled with spraying the foundation walls, box and plate makes for an extremely energy efficient home. Because the elimination of unwanted air flow, noise transmission is minimal.

 

[acudaowner]

there are a few video's with that very detail in them online as well as the cheaper insulation and a few other options for sound deadening some were pretty neat to see good luck finding the product that will suit your needs best .

 

[264win]

It’s only down falls are cost and if you ever need to remodel or do plumbing/electrical later, it is a royal pita.

 

[1moaoff]

As said its the way it seals all leaks. It also creates a vapor barrier.

We had our last home fully done during a remodel.. more 4000' sq ft our heat pump and fuel oil back up would go through more than 500 gal of fuel a year. After it was less than 100 and the house was quiet. Temp will be more stable.
If you have roof deck done also the attic won't be 160 degrees in summer and 5 degree in winter. The entire house felt different.

Newer home we had roof deck and basement rim done shortly after moving in. That alone made a big difference.

My gun room has a 2" layer of spray and then Batts to fill the stud cavity.... its great.

When we had the other house done it was full cavity fill. I ran conduit for electrical so it was a non issue. ( yes I know its overkill. The inspector was impressed. The amount of precise options I put in that house was nuts. But I thought I qould be there forever)

 

[EddieNFL]

Its not the R value, its the elimination of air infiltration that is spray foams greatest asset. Do a flash and batt, 2" of closed cell foam applied to the walls with 3 1/2" batt insulation. Best of both worlds. We do that to most of the homes we build, coupled with spraying the foundation walls, box and plate makes for an extremely energy efficient home. Because the elimination of unwanted air flow, noise transmission is minimal.

We're moving in a couple weeks and I plan to wall off the 3rd garage bay for a shop. I'll insulate door and walls. How much benefit should I see from doing the attic above the garage? Should I do all three bays? Central FL, so more about cooling, will probably never need heat.

Is this DIY or better left to you pros?

Appreciate any input.

 

[tomcatmv]

As a life long HVAC contractor/construction guy IMHO it is good shizzle. Just make sure you find a good, experienced, reputable install contractor as there are some horror stories out there about bad material and installs. I would also request to see the MSDS on the material they are going to use as there is some out-gassing issues to be aware of.

 

[rjacobs]

Do a flash and batt, 2" of closed cell foam applied to the walls with 3 1/2" batt insulation. Best of both worlds.

Do this.

if you ever need to remodel or do plumbing/electrical later, it is a royal pita.

You arent filling a 6" cavity with closed cell spray foam... That would be VERY EXPENSIVE. Most closed cell is sprayed ~2-3" thick at most. Its crazy dense.

When you see cavity fills like that, its done with open cell.


My attic is done with open cell spray foam, also the exterior walls and hot walls in the attic. The rest of the walls are done with batt only. I couldnt get my home builder to do flash and batt and the cost for open cell in the exterior walls was getting really stupid. 3700 sq. ft. house and highest bill so far in August was $120... My neighbors house is same size, no spray foam in the attic and his bill was $200. Im a big believer in spray foam.

 

[B21TLB]

Make sure you spray it thick enough to ensure you don’t get condensation between the flash and batt. You can can mold issues if done improperly.

 

[RedBaron]

I just had this done during a whole home renovation. We went with open cell in the walls and closed cell in the ceiling/attic. I think it's great. Just make sure you run access pipes for any wires you may want to run in the future (audio/video/ethernet cables) because you won't be able to add any after the fact.

 

[P-Squared]

We're moving in a couple weeks and I plan to wall off the 3rd garage bay for a shop. I'll insulate door and walls. How much benefit should I see from doing the attic above the garage? Should I do all three bays? Central FL, so more about cooling, will probably never need heat.

Is this DIY or better left to you pros?

Appreciate any input.

Eddie,

Absolutely insulate all three bays. I live in southern Arizona so we have heat, not the humidity. I put a 3 port mini-split heat pump in my 3 bay garage. I chose to put in ceiling cassettes in each bay. I live out there now working on projects. (has nothing to do with my MIL living with us - not at all)

 

[Jgunner]

I have open cell in my shop. It's stupid quiet, super efficient. My only problem is a few places it has delaminated from a couple studs. Just one side. Assuming because of themal variations but its a shop made entirely of steel, but I dont know much about it all

 

[c1steve]

Make sure the surfaces are free of dust and dirt. Otherwise the foam sticks to the dust, and not the wood. If it sticks to the dust, it separates from the wall, allows moisture to collect there, etc. Vacuum off all piping, etc, as well.

 

[Ruff 364]

Just had our new 3100 SF house and 1800 SF shop done in southern AZ. Did open cell on everything.

Could immediately tell major difference and the house is amazingly quiet inside.

 

[chevy_man]

It's all location dependant.

Here in the north, we commonly spray the cavity full and shave it back to the studs. This has to be done in 2-3 layers as it can get dangerously hot trying to spray that thick in 1 shot.

Nobody here bothers with open cell. Open cell is equivalent r-value to fiberglass, so it's pointless.


Closed cell should run r-7 per inch. Fiberglass and open cell are commonly arround r-3.5 per inch.

R-38 vs r-19 in a 2x6 wall. That's the math that matters.



Anyone that puts batts over foam is chasing pennies building cheap. It's pointless unless you're paying for foam and can do the glass with "free" labour. Even then there's better ways to save some money than what's inside your walls and effects your utility bills forever.

 

[308Gunner]

It is the best money I ever spent

 

[gunjunkie45]

Dose anybody have experience with closed cell spray foam insulation in exterior walls on a house? I’m thinking this is the way I want to go on our new house addition due to the higher R value it provides. Just wondering from those that have experience with it; how thick did you have it applied? (I have 2x6 walls) How is it for noise transmission? (Is if fairly quite or can you hear everything going on outside) Any other wisdom on the subject would be appreciated. For reference I live in zone 5.

Before taking any insulation advice... Where do you live? I don't need specifics, but what general area in what state? Insulation needs can be drastically different based on location.

 

[Lawless]

When houses are built that tightly, a system to vent to outside has to be part of the overall system.

 

[chevy_man]

When houses are built that tightly, a system to vent to outside has to be part of the overall system.

Make-up air unit.

They're a giant pain in the ass especially since they have to interface with kitchen exhaust hoods and fireplaces. Start the exhaust and the furnace has to pull fresh air in so the hood won't pull a vacuum and stop venting. As a kicker here we generally put 20kw heater grids in for the winter so the furnace can keep up with the -40* air.

If you're down south you can probably get away with just a simple intake into the furnace on a timed louvre to pull some outside air a few times a day.


High CO2 levels from people breathing and never opening windows and doors was common for the first few years.

 

[Lawless]

Make-up air unit.

They're a giant pain in the ass especially since they have to interface with kitchen exhaust hoods and fireplaces. Start the exhaust and the furnace has to pull fresh air in so the hood won't pull a vacuum and stop venting. As a kicker here we generally put 20kw heater grids in for the winter so the furnace can keep up with the -40* air.

If you're down south you can probably get away with just a simple intake into the furnace on a timed louvre to pull some outside air a few times a day.


High CO2 levels from people breathing and never opening windows and doors was common for the first few years.

Yeah I know it’s got to be done correctly and even then it can act like a cooler shut up too long (smells, mildew, unhealthy air)

Everything is a tradeoff.

 

[tomcatmv]

HVAC engineer here. Definitely install an ERV (energy recovery ventilator) Panasonic and Fantech are good to go. Around $450 at Grainger. These are actually a code requirement in some States/locales.

 

[babyguppy]

It's all location dependant.

Here in the north, we commonly spray the cavity full and shave it back to the studs. This has to be done in 2-3 layers as it can get dangerously hot trying to spray that thick in 1 shot.

Nobody here bothers with open cell. Open cell is equivalent r-value to fiberglass, so it's pointless.


Closed cell should run r-7 per inch. Fiberglass and open cell are commonly arround r-3.5 per inch.

R-38 vs r-19 in a 2x6 wall. That's the math that matters.



Anyone that puts batts over foam is chasing pennies building cheap. It's pointless unless you're paying for foam and can do the glass with "free" labour. Even then there's better ways to save some money than what's inside your walls and effects your utility bills forever.

this..
R-38 vs r-19 in a 2x6 wall. That's the math that matters.

I laid 4" of Rmax R6 above my garage ceiling. Wow. Now I have a storage space above the garage without all the dust from paper or fiberglass.
Added an A/C to Garage and my electricity only increased by 20-30 dollars in the summer. Garage stays 73 all day.
I added 1" of R6 to garage door along with some double bubble reflective foil. Door is 135 on the outside, and cool to the touch on the inside (before turning on the A/C)

Rmax R- 6, 2-in x 4-ft x 8-ft Thermasheath-3 Faced Polyisocyanurate​