Insulation questions

[Agotham]

First off want to say hello new member been looking at site for a while but this is first post. First my shop is largest I could build in the city limits 34*30 with 10.5 ceiling. Finally am ready to insulate it and thinking of using rigid foam double 1 1/2 on sides and roof with 1" airspace and double 1" on ends with an inch of air space, but don't know if I will be happy with it.Does anyone have experience with rigid foam board or have any suggestions. Spray foam is out for me at 4 k per inch that is alot of other stuff I could buy. It is metal building from absolute steel with 5' spacing of studs. Thanks for any information

 

[lakeroadster]

Polyiso is a good choice.

With a steel frame, and steel siding, how would you attach the foam boards?

Are you planning on sheathing the inside after insulation.. if so with what?

What does Absolute Steel recommend for their style of building?

 

[Agotham]

They recommend spray foam but foam board is option first layer cut to fit tight and seams taped will then frame a little for future cabinet placement and install second layer flush with studs and thinking osb interior walls diamond plate on bottom 4' over that

 

[lakeroadster]

With 5 foot steel support tubing spacing I'd check to see if you can get foam boards in 10 ft lengths... otherwise the amount of seams from using 8 ft pieces will be staggering (no pun intended).

Does the building sit on / and is supported by, the concrete slab?

 

[Agotham]

Going to be a bit of waste cutting it at 4*5 so 3' of waste per might be able to use some of that on second layer though just trying to find an option that will not cost a fortune yet have a good end result

 

[Agotham]

It is on concrete and attached to it base rails are sealed at concrete

 

[lakeroadster]

They recommend spray foam but foam board is option first layer cut to fit tight and seams taped will then frame a little for future cabinet placement and install second layer flush with studs and thinking osb interior walls diamond plate on bottom 4' over that

With 5 foot steel support tubing spacing I'd check to see if you can get foam boards in 10 ft lengths... otherwise the amount of seams from using 8 ft pieces will be staggering (no pun intended).

Does the building sit on / and is supported by, the concrete slab?

It is on concrete and attached to it base rails are sealed at concrete

So run the cabinet framing all the way to the floor so the floor supports the vertical cabinet weight.

Your thinking on using Polyiso is sound. And if it is indeed available in 4 x 10 sheets you won't have all that many seams.

The 1" air gap between the foam boards isn't worth the hassle.

 

[Agotham]

Was under the impression the air gap was needed with rigid foam my sides are 4" deep so 1 1/2 on wall and 1 1/2 flush leaves gap but if there is no benefit I'll do dual 2"