Evohome Opentherm Boiler decision and set up

[1animal1]

MTM, what's your thoughts and experience on a biscuit mix instead of the metal plates, aside from the hassle. I figure with any decent level of thickness in boards, I could do with all the thermal conductivity I can get

[mtmcgavock]

MTM, what's your thoughts and experience on a biscuit mix instead of the metal plates, aside from the hassle. I figure with any decent level of thickness in boards, I could do with all the thermal conductivity I can get

I'd stick with the plates. Have enough insulation underneath and it will work. I've done installations with spreader plates and without in between joists (Just clipped to insulation) and both work great. Comes through 18mm Chipboard with a self levelling screed on fine.

[1animal1]

Just a thought, if I did go down the biscuit mix route, fixing ply beneath the insulation, biscuit mix to the top of the joists. What's stopping me screeding the top... Surely the strength of the ply would be equivalent to that of floor boards above. I'm just thinking about the best possible outcome

[mtmcgavock]

Just a thought, if I did go down the biscuit mix route, fixing ply beneath the insulation, biscuit mix to the top of the joists. What's stopping me screeding the top... Surely the strength of the ply would be equivalent to that of floor boards above. I'm just thinking about the best possible outcome

No as the weight would be pushing down on the ply with no support under the ply. Your boards would usually sit on top of your joists to support the weight. I think you're just over thinking it, insulation, spreader plates and chipboard will work fine.

[1animal1]

No worries, thanks MTM 😁