I am looking to renovate a 1950 slab on grade w old, but still working radiant system. What are the main issues with going on top of current floor with warmboard, other than raising floor approximately 2″.
It’s actually a pretty straightforward process. You’ll want to put a vapor barrier down and make sure the slab is safe from any moisture intrusion. And, as you mentioned, you’ll need to account for the increased floor height (1-2″ depending on floor coverings) – and see how that might affect any stairs or sliding doors. But other than that – nothing to worry about really.
If you’d like to give us a call, we can help you get some accurate pricing. 877.338.5493