I suggest comparing efficiency and cost of blown foam with what you are considering.

This has no structural value as it is closed cell foam insulation and can not replace osb as a wall sheathing. It would be in ADDITION to the wall sheathing.

Need to be sure you are not creating a moisture sandwich (read about dewpoints) and causing condensation between your "walls".

^^^^^^^^^^^^

See here.

In a cold climate, air gaps like you're proposing are problematic and should be avoided.

Invest a small amount and run your diy design past a qualified professional.

You are creating a moisture issue with your plan. This is one of the big downfalls of trying to use a metal building as a residence. It takes a lot to overcome it’s drawbacks.

Your description of the project was confusing and inadequate. If you want good advice post details and photos of the metal structure and of what you plan to do with it. Also tell us where the project is located or at least describe the climate.

Alright seems like this might not work how i would like . Do you think spending the extra on closed cell would help fix these problems?

This is basically what im doing. This is the same insulation i have and want to add more without creating moisture problems. Located in Michigan

I knew the idea looked familiar...

Gus Fring provides housing for his secret lab builders. (Located in New Mexico.)

If you already have insulation like that pictured I'm afraid you've set yourself up for problems in trying to add insulation.

Well the insulation isnt up yet so im just weighting my options.

This is not IMO something to DIY oyu need real help to this right .This is the new code for insualtion in Micigan so start there

For example, Michigan’s code requires all roofs and ceilings in new construction to meet a thermal resistance rating of R-49—the equivalent of roughly 8 inches of closed cell insulating foam, give or take. There are additional standards for wall assembles, mass walls, basement walls, floors over unconditioned spaces, and even slabs and crawl spaces. The exact minimum standards in some cases depend on where you live—the UP, for example, has a higher bar to clear in some areas 4" is not going to be enough anywhere. Metal buildings are very complicatd to adapt to living space and need to be done perfectly.

"Invest a small amount and run your diy design past a qualified professional." To borrow a line from "Bill and Ted's Excellent Adventure," Excellent!

So does anyone have any real suggestions? I can do away with the blanket insulation and use that in the garage. I have no problem meeting R-Value code for the walls and roof. I just would like to know a way to stop condensation which is seemly going to be a problem. Vapor barriers, rigid board, etc.

HI, Bennett,

You're looking at this as an insulation problem. While insulation is an important design consideration, you need to consider how your planned home will perform as a "system." That includes considering such things as the site, the solar orientation, the size of the home, number of levels, materials of construction, the various construction details, and the conditioning of the indoor environment (HVAC) and don't forget the "V" part.

You'll be well served to consult with a professional who has expertise in building science/energy efficient residential construction with project experience in your climate zone. To find one, you can make inquiries of your local U.S. Green Building Council chapter, your local utility, search for energy efficiency consultants, etc. Be sure to ask about performance-based and energy rating alternatives to the prescriptive code requirements for insulation.

I think often when questions are asked here the person asking is in a position where the answer might not be what you want to hear but the answer needed. Building a home is a lot more than a shell that of course needs insulating but so much more is involved .We try to answer but with some caveats . Wether you take the advice or not is of course up to you

WUFI is a free software that can analyze various combinations of building materials in walls and roof for possibility of condensation and R-value. Offhand, on the roof, I think you may need to look at slicing the vapor barrier that is there, add more insulation in the girt space, then add vapor barrier and a finish. Those purlins can transfer cold through to the interior so they may need a thermal break, like a layer of foam on them. On the walls, 4" of fiberglass is not great but usually you can have 30% of your insulation on the inside of the vapor barrier. Run that through WUFI and find out.

I would say you're fine. This is typical conconstruction.

On vapor barrier. Because the current blanket insulation has a visqueen wrap. A vapor barrier. Venting is done with moisture control vents.

I would use closed cell spray urethane between the trusses if you needed more insulation. Although rockwool or fiberglass insulation will work. And it will work well to seal any air holes that are moisture problems. Otherwise if insulated enough the air gap will not cause a problem. You could use 2" blueboard or there are some great roofing insulation materials around these days. Install a 2x4 24" oc running horizontally for a perlin. That will be your nailer and thermal break. Another vapor barrier is not needed. I believe that 1/2" cdx plywood would look good and last longer than the 7/16" osb.

As noted, whole house envelope has to be balanced together.

That is a nice place. Good luck finishing it out

"This is typical conconstruction."

This is why you need local professional help.

Is conconstruction like Con Air?

Yeah ok folks. Yes typical for the building. Not the contents inside. But that's the ops deal.

And why the sarcasm delivered like this ?

I would not write it if it wasn't true. And by the way I have taken the time to take a couple years in tech college learning about whole house building envelopes. And been around the building industry for a while now

What is bad about it ? Looks like a nice warehouse with a house frame in it

rockwool or fiberglass insulation...will work well to seal any air holes that are moisture problems

At the risk of being nitpicky, I'm not aware that fiberglass and rockwool are good moisture barriers.

Please. If you take my comments out of context not good. Closed cell urethane seals air gaps nicely.

No fiberglass nor rockwool are moisture barrier retarders. Guess I believe that was kinda common sense.