How long does the floor take to heat up?

How long the floor takes to heat up depends on the construction of the subfloor. Uninsulated concrete subfloors will take considerably longer than insulated plywood subfloors for instance. For a rough guideline refer to the table below:

Subfloor construction	Heat-up time
WBP Plywood on timber	1 hr
WBP plywood with insulated tile backer board - 10mm	0.5 hr
Insulated concrete - insulation under screed	2 - 5+ hrs
Un-insulated concrete	2 - 8+ hrs
Concrete with insulated tile backer board- 10mm	1 hr
Concrete with insulated tile backer board - 50mm	0.5 hr