Best between joists UFH system

[Scott Coates]

We're currently renovating our property and we're looking to install UFH within the kitchen diner. 

 

We have a timber joist ground floor construction and my thoughts on the best system to use is the biscuit dry mix screed with the pipes laid within the biscuit screed. The build up would be as follows:

- 195mm x 45mm c16 joists

- Install battens and 100mm of PIR insulation between the joists

- Install pipes on top of the PIR insulation and encase with a dry mix 8/1 biscuit screed at 30mm depth flush with the top of the joists

- Overlay joists with 22mm P5 chipboard t&g boards, 3mm flexible screed and finished with an LVT 

 

Has anyone else used this build up/ system and if so have they found it work well and to be efficient? 

I have a few queries/ concerns which are:

- What is the best depth of biscuit screed to use and is there a better screed other than the biscuit screed which retains and distributes the heat better?

- Do we need to use polyethene sheeting between the screed and joists and the screed and chipboard flooring?

- Does the heat transfer adequately through the chipboard, 3mm flexible screed and LVT?

 

If anyone has any experience or knowledge of this system any advice would be greatly appreciated. TIA

 

 

[HughF]

I’d have my real reservations about getting the heat transferred up through the 22mm chipboard tbh….

 

I would be inclined to full fill the joist depth with insulation then use an overlay panel system like torfloor2, or if you have the buildup height available then an overlay panel with some self leveller over the top.