Foam insulation in ceiling?

[bams50]

Going to build a large pole barn, 55x120x16. Will have in-floor radiant heat and spray foam insulation; steel walls both inside and out, steel flat ceiling. My question is regarding the ceiling: What's the best way to insulate it?

I am in central NY, where we have 2-3 months of temps in the teens and 20s.

 

[Kaizen]

Geez that will be an expensive insulation bill. Since you have a metal ceiling already blown in cellulose is the cheapest. Add more for better r value.
Also consider spray foam just an inch thick on top of panels and walls for a air barrier. Then add batts and blown in.


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[bams50]

Geez that will be an expensive insulation bill. Since you have a metal ceiling already blown in cellulose is the cheapest. Add more for better r value.
Also consider spray foam just an inch thick on top of panels and walls for a air barrier. Then add batts and blown in.

It is unnerving, but I feel it's the best solution. I'd prefer spending more up front to minimize monthly costs as I get older.

 

[greg13]

Feel free to come over and "experiment" in my 24x32 to see what works best!

 

[sweetk30]

I had sunrise insulation out of dundee ny do my shop . 2 other buddys had them do there shops after mine .

I can say if you got the cash go for it . My shop was tested after in dead of winter with thermal cam and WOW hardlyand heat loss all over the whole shop . It also took out the wind storm creaks and snaps my shop use to have .

I dont have infloor heat tho . Just nat gas modine hotdawg left at 55* and main heat is hot air wood stove .

 

[Kaizen]

It is unnerving, but I feel it's the best solution. I'd prefer spending more up front to minimize monthly costs as I get older.

Definitely do pex in floor with insulation. I regret I did not every winter. Also get great doors.


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[NUTTSGT]

For a building that size, blown in cellulose is probably going to be the cheapest.

 

[walrus]

I did 2 inches of sheet foam on bottom of trusses and then r-40 cellulose on top of the foam. Works well here in Maine

 

[dfiler2]

I agree, the blown in will be the best choice, a well insulated shop will pay you back for many years. I used a mixture of foam, fiberglass and blow-in and my shop heats up very quick and stays very comfortable in summer. What do you mean by "steel flat ceiling"?

 

[megachimp]

I live in the same area and just DIYed blow in insulation. That's going to be your most affordable option. Be sure to add a vapor barrier underneath the insulation.

Also don't forget to insulate the slab. I see a LOT of barns around here not bothering to do that. It's required by the code and a good idea.

 

[racecougar]

Another vote for blown-in here. I did ~R-50 of blown fiberglass in the attic (with a vapor barrier between it and the ceiling) and R-19 batts in the walls. I am blown away by how well insulated/sealed the building is. My 30'x60'x12' building is in mid-MO, and I'm able to cool it in the summer with two little 6k BTU window AC units. For heat in the winter, I run a 30k BTU propane tank top heater for ~15-30 minutes to get it up to temp, then maintain it with a little 5kW 220V heater.

 

[dcg9381]

My question is regarding the ceiling: What's the best way to insulate it?

The BEST way is to use spray foam and close your envelope. This is especially important on residences as the air handling is in the attic envelope and doing spray foam can mean a 40 degree temp difference.

With no air handler and an "attic" floor, blown in options are good and probably the most economical.

 

[bams50]

What do you mean by "steel flat ceiling"?

The normal ceiling that every building I’ve seen has.

 

[Firebrick43]

spray foam has no advantage in either air sealing nor insulation value to a decent blow in cellulose job in the ceiling. Cellulose is better R value per inch, better R value per dollar, and great air sealing capabilities in ceiling applications.

Spray foams advantages come in places such as walls that are limited in thickness and have lots of nooks and crannies. Even then cellulose can outperform spray foam but unlike the relative easy and low skill needed to blow attics, performance of the blower and skill of the installer is very critical in dense pack walls. Mistakes cause voids and most dont want to install the netting required.

Also in heating climates it has some advantage to place foam on the outside of the envelope as it forces the dew point in the foam and not in the cellulose or fiberglass. This foam still should have an airspace between it and the outside siding to allow it to dry out. Even XPS can absorb some water and I have seen several buildings with damage from "closed cell " spray foam that absorbed water and was not able to dry because it was sprayed directly on the back side of the metal siding. I have also seen high dollar house with cedar siding have moisture satuation issues because the siding was attached directly over the tyvek and no rain screen (air gap) installed.

 

[dcg9381]

I disagree the the sealing the envelope portion being better with cellulose.. The R value of cellulose (3.7) is close to the R value of open cell (3.2) and inferior to the R value of closed cell (6).

To me, there is simply no way that a blown in material that settles (gravity) and usually is not adhesive can match the ability to seal that expandable foam has. Shoot cellulose at a corner, shoot foam at a corner and compare, let alone a framed opening of "typical" quality where there are gaps.. Cellulose simply won't do the same job sealing those up.

I do totally agree that cellulose is certainly more cost effective per R value / inch. And there are places (like the deck of an attic) where it's use may be superior, especially when considering value per dollar.

If I had substantial depth in a wall or in a roof, I'd think that the best solution would be a combination of relatively thin sprayed on closed cell and then backing that insulation with a more cost effective option like cellulose... And I'd personally choose cellulose for a situation where I had an attic deck with no air handler in that space over the same amount of dollars spent on foam.