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Insulation Options for Pre-Fab Metal Building

adamflyer's picture

I am planning on putting up 34x54 metal building shop with 16' eaves. I am thinking of going with versatube or a conventional red iron type construction from a local metal building company.

I know the standard way of insulating them is fiberglass insulation with a plastic backing between the frame and the metal panel siding. I don't like this idea for two reasons.

1. The inslation has a lot of pinch points which reduces its R value.

2. I'll be building the shop and I hear it is a real pain to install this way.

Of course I could use spray foam but it costs so much more its rediculous and I will be doing things like welding in the shop and I really don't like the idea if it being flamable.

I am thinking of framing out the first 8ft of the walls with 2x4s construction 24" o.c. with 5/8" drywall. I could then easily isulate this wall area with conventiaonl fiberglass batts. Or would blown in cellulose be better? But then what of the upper 8ft of wall area and the roof? Is there a good way to attache some sort of insulation with netting or something like that. Does anyone know of any other options?



Insulation (post #215512, reply #1 of 3)

You might look into mineral wool (or rock wool) batts.  They come in several stiffnesses and thicknesses and reportedly can be attached to wall surfaces with adhesive.   There is a  YouTube video showing how to attach the batts to a block wall.  For some reason I can't cut and paste the address, but you can search on "How to Attach Insulation (Rock Wool) Using Adhesive".  Like most insulation installations, it looks rather labor intensive.  Currently, the primary supplier of rock wool to the DIY market is ROXUL.  I think some, but not all, configurations of Roxul batts can be ordered through Home Depot and probably other suppliers.  I am planning on using the Roxul batts (or whatever brand I can get) in building my house and shop.  Most people that have worked with the rock wool batts indicate they are superior to fiberglass in most applications.  I don't know if rock wool could be adhered directly to a corrugated steel wall or if some type of substrate would need to be attached to the wall first.  Rock wool is fire resistant and doesn't retain water to any great degree.  I would probably cover the lower wall areas, particularly in a welding area if you want the wall to keep looking halfway decent.  I haven't used Roxul batts yet but the mineral wool I have worked around is like miniture strands of razor wire, so really good gloves are a must. 

There are a number of discussions of rock wool on Green Building Advisor and other discussion forums. 


It's very common is use wet (post #215512, reply #2 of 3)

It's very common is use wet cellulose to insualted metal buildings. 

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

Thanks for the reply. I had (post #215512, reply #3 of 3)

Thanks for the reply. I had not seen it used granted I have not been in a lot of metal buildings. All the ones I have been in use fiberglass between the exterior sheeting and the frame.

With wet cellulose do you need to cover it up with drywall or something else or can it be left exposed? I am not seeing any information on this on the web.