slab insulation for radiant heat

[SSN685Submariner]

I could really use some help !
I am constructing a 28'x36' Geobarn and I have already installed 1200' linear feet of 5/8" pex tubing over slabshield foam insulation. (R 2.9 ) My concrete contractor simply did not allow room for thicker insulation as I would have preferred 2" polystyrene. What is my best option for insulating the perimeter of the slab to improve thermal efficiency ? Can I insulate the outside and cover the insulation which is above grade with some sort of decorative veneer ?
Many Thanks

 

[rburke65]

Welcome to Garage Journal. First of all, it might help to know what part of the world you reside. And if you go a search there is a lot of info already here on the subject. Any chance of digging out 2" of your base to allow for the 2" of poly? And there're cement applications to cover insulation. I'm not versed in the products, but I know they are out there.
Me....USN....'66-'69

 

[hidollartoys]

The issue with parameter insulation used on wood structures is termites. They love to use the foam as a route to the structure. This is why a parameter stem wall with a slab inside is perferred construction if an insulated slab is being constructed. Then the structrue can be built on top of the stem wall w/o parameter insulation on the concrete. All the slab insulation is on the inside on the stem wall.

 

[Dave Maxwell]

I'm puting 6 mil visqeen (sp) against my wood and then the foam board. The wood is treated and supposedly guaranteed for fifty years. Should I be concerned and check with Morton buildings on possible void of warranty

 

[hidollartoys]

Cant answer your warranty question. Treated wood is not where I would worry. If the structure had treated posts and untreated siding, trim and/or purlins then I would be concerned.

 

[Highbeam]

Treated wood. Treated for decay or treated for termite resistance?

 

[Dave Maxwell]

Probably decay. I am going to have it treated for mites before I close it all in