Planning To Build a Shop/Garage, Insulation Question

[Cord]

Re: Planning To Build a Shop/Garage, Insulation Question. Update

If you tape all the seams of the foam boards, technically you don't really even need plastic. But I put my plastic on top of my foam because it was easier to adjust for perfect grade/level going one board at a time (I did not tape the boards). It doesn't really matter. Just need to keep most of the ground water from ever having a chance to come upwards.

Foam is NOT a vapor barrier, so taping the joints does nothing to stop vapor drive.

If the space will be "nice", then a vapor barrier would be recommended. If you want to put a floor down, then it's mandatory. If you are using standard poly, I'd put the plastic on top of the foam because that gravel will punch thousands of holes in the plastic. If you were using a vapor barrier like Stego, then it would go under the foam because it's tough enough to withstand the stone.

 

[Milo]

Thanks deezler and Cord, It'll have vinyl flooring so it'll have to be dry. I'll test the concrete before laying the vinyl and water proof seal it on top as well if necessary. OK on top the foam the plastic goes. Unfortunately they have the less desirable (for this application) blue foam here for under the slab which becomes less effective when wet. I may try to see if I can get the pebbly white foam (XPS?) and let them take their's back since the foam under the plastic and potentially exposed to moisture.

 

[Cord]

The blue or pink foam is XPS and that’ll be better than the white polystyrene. The foam is closed cell so it won’t absorb water.

 

[Milo]

The blue or pink foam is XPS and that’ll be better than the white polystyrene. The foam is closed cell so it won’t absorb water.

Ok so the rigid blue foam is OK, thank you. It'll go down first with plastic on top prior to concrete. It'll be a little difficult to get it up and across the ICF wall as they're doing everything in one pour, I'm anxious to see how they do it.

 

[Milo]

Well they had the plastic *under* the foam and were ready to pour when I got there. They said that's the way they've done it and never have had a moisture problem with a basement or slab since doing so, so I reluctantly let them continue. They also had screw heads 2" exposed into the concrete side that had been screwed through the foam into the treated band board. The idea was the poured concrete would compress the plastic through the screw heads so the heads would be imbedded in the concrete which would secure the band board to be followed up by using Tapcons. That didn't work out as the concrete did not force the heavy plastic to be penetrated by the screw heads. The band board was attached to the edge of the slab by Tapcons the next day before the supports were removed. It made me feel a little better that compacted gravel would have a difficult time puncturing through that tough plastic.

Filling the ICFs first so plastic could cover the stem wall and up the edge.




5 1/2" concrete floor poured.









Framed and braced.




Sheathing on and carport piers and beams done, trusses next.

 

[Milo]

Making headway.

 

[deezler]

Pretty sweet! Looks like you'll have a very well constructed building.

 

[Milo]

Thanks deezler I hope so.

Some more pics to catch up to where we are.









The siding is Celect by Royal and interlocks together.









Still waiting on the door so they can finish siding the front then put the trim on. Drywall should be finished today.

 

[Milo]

Wet and cool today so they're using a portable heater. Rain is supposed to be over for a few days.

 

[Milo]

Finished and very pleased, final pics.