Insulating a Quonset silverboard or refectix?

[suburban99]

I am insulating my 30 x 40 quonset here in BC. It doesn't get too cold in the winter or too hot in the summer but the condensation is crazy. I have priced out spray foam (ouch) and decided I need to use an alternate product.

My plans is to attach furring strips every 2 feet with coupling nuts and all thread. The strips will be attached with nuts and washers. I will install these every 4 feet matching the holes. Each row will be alternated. Then attach either reflectix roll foil or siverboard .623 inch insulation. Your thoughts?

 

[txvwnut]

I used coupling nuts and fender washers to hold foam board insulation in mine with the plan of firring strips on the outside of the foam board to attach a wall covering to. The stuff I used is 3/4” thick and I just compressed it with the fender washer till the bolt threads poked through then screwed the coupling nut on. You’ll still get condensation but it will be behind the foam.

 

[Warrenator]

I did spray foam on my shop, yes expensive but it is sooooo good. No condensation, no temperature swings. no noise. I had mine done professionally ($$) but there are kits for DIY out there. Shape of a Quonset hut is so awkward..... dunno if it would be worth it for the major labor to try a bunch of foam board screwed up by various means.

Perhaps a good compromise would be DIY spray foam but spray it maybe 1/2" thick instead of 1", make it go twice as far. If you think of how well a 1/8" foam coffee cup keeps hot coffee hot, even a thin layer of foam would be enough insulation to keep the condensation down.

I would avoid Reflectix, I used it in a garage in SoCal to keep the roof from baking the whole garage and it helped, but it is not really insulation at all. Just a fancy mirror.

 

[txvwnut]

DIY spray foam kits aren’t any cheaper than having it done professionally plus I’ve read reviews on a bunch of kits and they all had complaints of the spray setup not working properly or at all. Hanging foam board isn’t all that hard although it doesn’t offer the same R value of the spray foam but it is better than nothing.

 

[Stuart in MN]

Then attach either reflectix roll foil or siverboard .623 inch insulation. Your thoughts?

Find out what the real R values are first. Many of those foil products have artificially inflated figures...they may provide a good radiant barrier, but in reality have a very low R value when it comes to actual insulating.

 

[Firebrick43]

Find out what the real R values are first. Many of those foil products have artificially inflated figures...they may provide a good radiant barrier, but in reality have a very low R value when it comes to actual insulating.

+1 reflextix r value numbers are as real as unicorn farts. By silver board I assume your talking 5/8 polyiso foam with a foil face such as celotex? If so its good stuff. If you want use of the foil face to reflect heat back in it has to be pointed into an airspace and not covered or painted.

Spray foam is not recommended to be applied directly to metal. It voids most manufactures warranty(not that yours still has a warranty) as it can corrode the metal if the two components are not mixed perfectly.

 

[suburban99]

Here's a link to the product. It appears to be called SilveRboard in Canada.
Polystyrene with polypropylene reflective barrier.

https://www.amvicsystem.com/products/hd-foam/silverboard/#gallery