Foam board insulation VS spray insulation

[Johnv656]

First post since joining.
Putting up a new 40X40X16 pole barn, will have in-floor heating, 2 inch foam 25PSI under the floor and around the perimeter.

My question is how would 1 inch foam insulation with heavy foil compare to having sprayed on insulation?
Attached is a photo of the foam board I am considering.
I assume the foil cover would go towards the interior?

Looking for the pro's and con's.

Thanks in advance.

 

[maxpower_hd]

I don't know the numbers off the top of my head but I know that the closed cell type spray foam you have installed by an insulation contractor has a higher R value than other insulation types. And if I remember right the rigid board has a lower R value. I would do some research and see which is better. Then cost would be the next deciding factor for me.

 

[jbwilkins]

The spray foam will help to seal air leaks much better than a board. That's one of the big positives of the product.

 

[woodzy]

I just finished my basement and all exterior walls were sprayed at least 1" thick and in some places 2" thick and then on the 1" thick, I added fiberglass. I really (really) like this spray foam - it seals all cracks so there is zero chances of bugs, dust, drafts, or just about anything getting through it. It was a little on the expensive side, but I'm in it for the long haul.

 

[zendriver]

I knew a well driller in Montana, that had a huge pole barn insulated with 4" spray foam. he heated the whole thing nicely, with a medium sized wood stove.

If I was insulating with foam, it would be spray foam. Too many air leaks, otherwise.

 

[kaje36]

If you have a professional do the closed cell spray foam,.. it will be about 4 times the cost of PolyISO foam board. I just got a few quotes for closed cell in my 24x36 garage, and the cheapest was $4400, and that's for 2 inches, no one wanted to spray less then that. I looked at pricing of the DIY kits, and it was MORE expensive, then having a pro do it.

I ended up with some factory seconds PolyISO for $15 a sheet shipped, I bought about 10 extra boards and only cost me $1125 (75 sheets 4x8x1.5) I plan on great-stuffing the edges (open cell). it wont be perfect, but would be a lot better then the alternatives.

 

[theoldwizard1]

For a pole barn (metal siding) Zendriver is correct. Spray foam is the best way to seal up air leaks.

BUT

Woodzy is also correct ! 2" of closed cell stray and then as much fiberglass as you can get in the cavity (without compression) is the cost effective solution.


IF

You are doing stick built and using "engineered" sheathing (like Zip) and tape, then you can use foam board (without aluminum facing) and hand held spray foam gun. WOrk carefully and you will get amazing results.

 

[btdobie]

Make sure you get a Spray Foam contractor that knows what he's doing. I have seen dozens of stories like this.

I'm not here to say that spray foam is bad just understand the risk. As an insulator it is a great product. Fire resistance is another thing to consider.

 

[Johnv656]

Thanks and keep the feedback coming.

I can purchase the above board for $12.80 for a 1X4X8 sheet, delivered.
1 1/2X4X8 sheet for $16.00 per sheet

As an FYI

 

[Kaizen]

wizard is right on. envelope it in 1 or 2 inch spray and then fiberglass. I swear it would be cheaper to have a few guys buy the whole rig and a few barrels of that stuff then to have someone spray it. if I remember when I got some done the closed cell was 80cents per inch per 1 sq foot. great if you can afford it.

 

[Randy in Maine]

X 2 on the spray foam option. I have done it both ways and it just seals everything op so nice.

 

[countrysquire]

Spray foam really works well for insulation, but is surprisingly ineffective for blocking sound (a minor downside). My house was done with spray foam when it was built, and it is so nice when you have to go into an 80 degree attic during a Texas summer.

 

[theoldwizard1]

Spray foam really works well for insulation, but is surprisingly ineffective for blocking sound (a minor downside).

Mineral wool (a.k.a. rock wool) is good for sound deadening.

Roxul makes a version call Safe'n'Sound. Sound deadening AND fire resistant,

 

[cjcocn]

If you want the best of both worlds (effectiveness of the insulation vs cost), spray a layer of spray foam and then finish it off with fiberglass batt or mineral wool (for the fire retardant properties).

Check your codes for moisture barrier requirements. In my area (northern Manitoba, Canada) we need 2" of spray foam to get the required moisture barrier.

Spraying the whole thing with spray foam would be nice in terms of creating an effective moisture and thermal barrier, but it would be the most costly option.

(for this area) Spraying 2" of spray foam and then finishing it off with fiberglass batt or mineral wool is a great way to get a complete seal (eliminating the need for poly vapor barrier and greatly reducing the amount of thermal breaks), reach your minimum RValue requirements, and not spend a ton of money.

 

[NUTTSGT]

The foil faced insulation that you are considering gets alot of it's oomph from the reflectivity. (is that a word ?) If you plan on covering the walls with something like OSB, drywall or metal, you are going to be losing most of that edge.

I'd do like most of the others have recommended, flash & batt, spray foam and top it with fiberglass (or rock wool) insulation. It might be a large cost up front but considering you are using in floor heat, it'll help save costs of heating. Once you get that large concrete mass of a floor warm, the walls and ceiling insulation will help hold it in, giving you a really great place during the Winter months in Michigan.

Just remember, anything you spend on insulation is an investment and will continually yield a ROI everyday you're heating or cooling that place.

 

[csp]

Thanks and keep the feedback coming.

I can purchase the above board for $12.80 for a 1X4X8 sheet, delivered.
1 1/2X4X8 sheet for $16.00 per sheet

As an FYI

What's the R-value of each? Not all rigid foam has the same R-value.

 

[383]

Foam board can be made airtight, in my basement I used 2" with reflective membrane on both sides and taped the seams. The main advantage if using sheets is to have it installed continuously with no thermal breaks. Even with spray foam, you can see cold spots at the studs with a thermal imaging camera.

My uninsulated concete wall was around 66 degrees with the wood stove running hot before insulating. I wanted to see how much difference the insulation made, so I cut a test hole through the insulation. The next day I had almost a 30 degree difference.