Pole Garage insulation and radiant heat

[Cadmandu]

Hi all,
Im building a 30 x 36 x 10 pole construction garage.
How do i attach the double bubble vapor barrier to the roof?
How do i install blown insulation? Do i need a drywall ceiling?
What kind of insulation do i use for walls. I would like to install the fiberglass batten type but not sure the best way to attach.
Should i have it wrapped with a house wrap before the metal goes up?

Thanks

 

[kberjian]

Welcome!

Typically your ceiling would have the vapor barrier stapled directly to the underside of the rafters. Depending on the rafter spacing you would need to put up strapping to span between them on 2' centers. You can chose to drywall the ceiling, metal panels or even chip board depending on your desire for the finish product inside.

The blow in insulation comes in large bales and you feed it through a machine you can rent from Home Depot, which breaks it up and blows it through a hose. You have a person man the hose and walk through the rafters while filling the it to the desired depth to get your R rating.

If you look at my build thread that is linked in my signature I am going through a similar process now. You should understand what you want to do for the wall finish on the inside. If you will be doing drywall or chip board on the inside you should put strapping on the inside of the posts or frame it out like a typical wall.

I chose fiberglass batten type in my walls. You get the correct thickness and just stack it inside the wall. There is a good amount of friction between the wood on either side and it holds itself in position pretty well. On top of the insulation you can install the vapor barrier at that point.

Hope that made sense.

 

[Cadmandu]

Beautiful garage is that a 100 amp sub panel?
Did you attach the double bubble to the bottom of the rafters.
I thought that it would go on the bottom of the roof purlins. The foil side up so it will reflect the heat out.

 

[Firebrick43]

The condensation blanket is put over the trusses before the metal is laid. Double bubble is overpriced snake oil. I would just use a 1/4 fanfold xps myself.

To blow cellulose you rent the blower. It can be placed over drywall but in a pole barn I would staple up a heavy visqueen and tape the seems, Screw up metal liner(a thinner version of pole barn roofing) and blow on top.

As far as fiber glass in the wall they make it in 4' 5' and 8' widths. You place two scrap pieces of 2x4 on the insides of the poles just at the header beams. screw together two 2x4s the width between the poles minus 3/4" together with the fiberglass bat top edge in between. With help holding the batt weight you can poke this assembly up inbetween the header boards at an angle and then straighten it out and set on the two blocks. Some just set one block and then screw the second up when installing the batts.

 

[jack stand]

Yes house wrap, specifically Tyvek, Typar or Hydrogap, all taped.
Save your money and skip the bubble joke, it's a BS gimmick that just won't go away.
I've found that if you're planning on a finished, heated and insulated interior, it's cheaper to simply use 16"o/c traditional framing from the start. For a proper job, you'll end up building this in between your posts anyway.