R-foil insulation

[lukey]

I recently had a 24x46 steel garage put up and am now ready to get it insulated. Living in central Illinois, the temps outside swing worse than a woman going through menopause! I got a really good deal on 3 rolls of rfoil bubble type insulation the other day. Do you guys think that is enough if I line the entire inside with it or should I put some 2” foam boards in the walls behind it? I won’t be cooling the shop in the summer, but I will be heating it in the winter. As for the spray foam insulation, I would love to do that but can’t spend the $5000 on that.

 

[Rabbit929]

Me personally, for walls I think foam is a waste. It’s good, but I’d much rather use foil or paper back rock wool for walls.
As for the bubble wrap, I personally am not a fan. Might make a good temporary for the ceiling but let’s see what someone else says, I have very little expirience with it.
It’s my understanding that it’s to be used on top of your existing insulation as a radiant barrier, so I’d still say fill the cavities with rock wool and foil over top of it, then sheet rock or osb.
I’d even tape the seams because it could double as an air barrier.

 

[TractorJeff]

Do the roof or ceiling first as heat rises!

 

[Firebrick43]

Sorry but bubble insulation is snake oil. It has little value other than a condensation blanket. The foil can help some but only if your reflecting into an airspace.

I would return it and insulate another way, either foam or fiberglass/rock wool. If you do use foam and leave it exposed, make sure you use the isocyanate foam with the foil face inwards. It has much better fire resistance than xps or eps foam.

 

[Randy in Maine]

Another insulation option to consider is dense packed cellulose. Installed correctly it is quite effective and can be pretty cost effective.

 

[Hubmonkey]

My 24x36 polebarn was done with double-bubble wrap and it pretty much is only good for is the reflective properties of it against the metal. It is a Radiant Barrier and nothing more. At the time I had it built I did not know any better and now I am putting actual insulation in... 2x4 walls with R13 paper faced then sheetrock.. the roof will be vinyl faced in the trusses.

Hub

 

[PWC Repair]

My 24x36 polebarn was done with double-bubble wrap and it pretty much is only good for is the reflective properties of it against the metal. It is a Radiant Barrier and nothing more. At the time I had it built I did not know any better and now I am putting actual insulation in... 2x4 walls with R13 paper faced then sheetrock.. the roof will be vinyl faced in the trusses.

Hub

Exactly this! Don't think of the foil bubble stuff as insulation, just radiant barrier. Go ahead and line your ceiling with it. THEN insulate. My 30x50 is insulated with 3" foam board I got cheap! Check out my build thread below.

 

[Firebrick43]

But if you put a radiant barrier up against the roof deck, it’s useless. Radiant barriers have to have an air space to reflect in to or they don’t work.