Insulation pros and cons

[M-technik-3]

My new space is stick built and of newer construction vs my old 1950's garage.

The previous owner did not close up the garage so I am debating insulating to the prevent critters from gaining access and so I can work when it's cold. We have moved only a town away but our elevation has jumped 800 feet so it is cooler here, last night it dipped into the mid forties already.

My pool isn't even closed yet yikes next week though.

The question I'm thing the best method since the walls are bare would be to Close Cell spray foam vs traditional fiberglass batting in a 2x4 wall that will only give me the r13 maybe r19 value what does spray foam R factor equal too? I plan to add sheetrock and do the ceiling as well since I have an In-law apartment above the garage. I also need to put a vapor barrier of some sort to keep smells out. Thoughts on that.

 

[bazzateer]

Leave a small air gap between the insulation and the outer wall (stops moisture causing rot of the outer wall). Fit a vapour barrier between the insulation and sheetrock.

 

[M-technik-3]

If I use Closed cell I should not have to do that correct?

 

[soapii]

If I use Closed cell I should not have to do that correct?

Closed cell is it's own vapor barrier (open cell is not).

--Joe

 

[pmiranda]

Insulation won't keep the critters out.

 

[csp]

Ballpark is about R7 for every inch of foam.

 

[M-technik-3]

So it's will be barely more than using simple fiberglass. damn but it will be less drafty and even that's not true after putting up drywall which contributes to R factor a bit.

 

[DC73]

what does spray foam R factor equal too?

Closed cell spray foam is a good choice for you. R-value is about 6.5 per inch of foam. Open cell spray foam has an r-value of about 3.6 per inch.

If I use Closed cell I should not have to do that correct?

Correct

DC

 

[csp]

Batts for 2x4 are R13. Being conservative at 6.5 per inch of foam you'd have almost R23. I wouldn't call that barely more than batts. There would be zero air movement as well. The cost of closed cell is also significantly higher than batts.

 

[911mike]

If you can afford to spray foam do it. I did part of my build in fiberglass and some in foam.
The foam is Way warmer. It makes a air tight seal.

 

[Cave Creek Ray]

Problem with spray foam is most companies charge a minimum to come out and gum up their equipment. The local place here in PHX that advertises a lot wanted $7k minimum to show up. That's a lot of batt for what small areas I needed. I guess business is good.

Not sure of your sq ft area but I just firred out two walls in my workshop against a 1" foam sheet with plastic on one side and foil on the other. The foil is outside against the concrete block and then I did R-13 batt inside the wall structure. If you wanted to used the 4x8 foam boards (Home Depot) you could put three layers in your wall with two foils aiming in and one aiming out. That would give you great heat retention in winter and very good heat defense in summer.

Not cheap but far less expense than spray foam unless you are doing an entire building.

By the way, with the reflective foam on the outside and the R-13 inside under sheet rock, my barn office (no A/C or heat) has stayed amazingly cool in these final summer days (100F). Had a chilly rain system move through this week and walking into the office was "warm and toasty" compared to the 55F and rain outside. Temperature stability: What a wonderful thing after not having it.

I am very pleased.

Good luck.

Ray

 

[LX-Markham]

The question I'm thing the best method

what is the best?
depends how you qualify that.

best method: closed cell foam
best value: fiberglass batts

Only downside to foam IMO is having to get all your in-wall services planned out and installed in advance.

 

[M-technik-3]

I had a delay in project so finally ended up getting some quotes for my main garage.

26 wide by 34 deep two car, r32 on ceiling to keep fumes out of living space and r24 in the walls, plus sealing all other odd spaces created by garage addition created in eaves.

Both companies spray Icynene, the company that came out and took measurements and is further away came in at 5.5K I almost choked when I saw it but then I got the second company's 6.95K and they are 12 miles away.

Needless to say we are going with the first company. I am done with rodents. having the walls done in spray will help me enjoy the space in the winter without having to heat it yet. I have a wood stove in the barn.

 

[theoldwizard1]

The question I'm thing the best method since the walls are bare would be to Close Cell spray foam vs traditional fiberglass batting in a 2x4 wall that will only give me the r13 maybe r19 value what does spray foam R factor equal too?

The best solution is a combination of the 2 !

Spray foam 1-2". This will seal all cracks. This will give you a vapor barrier so no moisture will get to any additional insulation. Make sure they go above the top plate, but not into the soffit. It is NOT a guarantee against critter gnawing holes in it. (Fill existing rodent holes with stainless steel wool before spray foam.) Then add additional insulation.

Check pricing of "wet" cellulose sprayed on to the walls. It does require some type of wall board to be applied before it completely dries out and starts to crumble.