Flooring over UFH in insulation

[BotusBuild]

Floor makeup is web joists with 18mm T&G plywood so far. On top of this will be grooved UFH insulation and pipes. I plan to put some hard cover over this before the final flooring (LVT glued or click).

 

Logic and common sense tell me a stiffer board e.g. 9mm plywood screwed down through to the 18mm plywood makes the most sense.

 

Is it sensible? Have I overthought/over engineered? What would be an alternative I might want to consider. 

FYI-the grooved insulation and UFH is not up for negotiation so lay off that part 🙂

[JohnMo]

Just a matter of working through the insulation values of the floor above the pipes and see how that affects your flow temperature. If the flow temperature stays sensible that's your answer.

[nod]

1 hour ago, BotusBuild said:

Floor makeup is web joists with 18mm T&G plywood so far. On top of this will be grooved UFH insulation and pipes. I plan to put some hard cover over this before the final flooring (LVT glued or click).

 

Logic and common sense tell me a stiffer board e.g. 9mm plywood screwed down through to the 18mm plywood makes the most sense.

 

Is it sensible? Have I overthought/over engineered? What would be an alternative I might want to consider. 

FYI-the grooved insulation and UFH is not up for negotiation so lay off that part 🙂

I’ve just done one for a mate 

I put a 10 mil screed over it before tiling Super Simple  This went straight down on a 22 mil cabba deck Glued and screwed 

[JohnMo]

1 hour ago, nod said:

put a 10 mil screed over it before tiling Super Simple

We did OSB and then laminate floor over 

3 hours ago, BotusBuild said:

grooved UFH insulation

It was pretty rubbish - screed over sounds much more sensible, full contact with pipes and aluminium, should perform much better.

[nod]

The mad thing is that this house is insulated within an inch of its liTaped membrane and every external wall is batoned out The best treble glazing money can buy and he’s convinced that he needs UFH on the two upper floors We have a fan running constantly while we are tiling as none of the windows open Except electrically operated patios Which won’t or don’t work yet 

and we are only in April 😂😂

[BotusBuild]

17 hours ago, nod said:

 

I put a 10 mil screed over it before tiling Super Simple  This went straight down on a 22 mil cabba deck Glued and screwed 

Can I ask what screed did you use?

And what glue?

And those screws look special?

Edited Monday at 11:20 by BotusBuild

[nod]

We used level master plus and the screws and washers are tile board fixers You can get them anywhere 

PU glue for floorboards Done by others