With laminate, you'll get the best R value out of thicker planks, like the Formica Quintessa line.
Quiet Walk felt underlayment or Floor Muffler both have higher R values than many other underlayments.
Edited to add - I know you're looking at in-floor heating and I've never sold/installed it so I'm skipping that part of your question..
You should always moisture-test your floor prior to installing wood or laminate.
Have you considered carpet and pad? An 8lb pad and dense plush carpet would provide some insulation and aren't affected by average moisture; it can evaporate off from the slab right through them.
Quiet Walk felt underlayment or Floor Muffler both have higher R values than many other underlayments.
Edited to add - I know you're looking at in-floor heating and I've never sold/installed it so I'm skipping that part of your question..
You should always moisture-test your floor prior to installing wood or laminate.
Have you considered carpet and pad? An 8lb pad and dense plush carpet would provide some insulation and aren't affected by average moisture; it can evaporate off from the slab right through them.
