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Discuss UFH Joist system and Manifold selection - Evohome in the Water Underfloor Heating Installations area at

Evening all

I have been researching the hell out of this, following my last project. Currently ripping half the kitchen out to remove a wall and make our downstairs open plan - If you wouldn't mind me running my plans by you to hopefully pick any obvious holes in.

Current floor is standard T&G boards with decent sized 400mm centre joists with a relatively short span for the vast majority. The initial plan is to create a UFH ring in the current kitchen, another ring in half of the living room which the kitchen will become part of once the wall is remove, and future proof for when the main part of the living room and extension get built.

Current thinking is to remove the floor boards,screw batons to the joists and fit 75mm Kingspan or similar 25mm below the floor level. After jostling over aluminium plates and realising i need to refit with glued edged chipboard (18 0r 22mm?), i figure i am best making the most of the efficiency below the boards, going for a dry biscuit mix instead of the plates for thermal mass - any tips on how long this will take to settle/dry before refitting boards? I will be using 16mm Pert Al Pert pipe held down with plastic clips to the insulation, neither ring will be more than 75mtrs.

I am running a full Evohome set up using Opentherm, so will be buying the HSS80 controller, or at least fitting a relay switch to start with (on a single stat) to power the UFH actuators (2 to start with) and pump, then wiring in an AO valve in parallel to my current AO CH valve, both designed to close when HW is on demand. The actuators will be standard AClosed 2 wire, no brand preferred but presume they are all relatively the same given that they are simply on/off switches, as long as i get the thread right.

My current dilemma assuming the above is ok, is the manifold. I note there's several price points available and believe you generally get what you pay for - current thinking is either an Emmeti unit EMMETI 5 PORT MANIFOLD WITH GRUNDFOS PUMP MIXING SET And 16MM MLCP PIPE CONNECTORS

Or an IVAR 6 Port Underfloor Heating Manifold with Uni-Mix Temperature Control Valve and Grundfos UPM3 Pump | Underfloor Parts The IVAR being about £80 cheaper and with a better pump (ignore price in link). I want to know opinions on this and if i am missing any other obvious options. I will add, I want to stay away from pushfit given the extra cost of the 15mm pipes and difficulty in bending for UFH purposes.


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