Going back to radiant heat... How do we know what insulation is more efficient. If 2" board is good then why not invest in 4" and be even better. I know there is a limitation of no additional return but who says its 2" I think you see my point. The company I have talked with to do my floor heat had the same question. They were expanding and built 2 warehouses the same size. Everything the exact same except one building they used 2" styro and the other they used foil bubble. Energy costs are nearly identical. I dont think anyone can really say the money they spent on 2" foam is paying off. Thoughts??
How Do we Know??
- Thread starter 93L#3008
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Stee6043
Well-known member
"More efficient" is a really tough position to argue when it comes to insulation. It's more about at what point does the R value increase so insignificantly that your dollar is better spent either on the heating energy itself or some other system enhancement. Longevity, performance, installation costs, etc are all part of this wild calculation...
Mr onetwo
Well-known member
I have seen studies that indicate that 3" underslab is ideal.2 layers of 1 1/2" with staggered joints works good and the material is common.Anything thicker is a waste of money IMHO.