Nickfromwales

Good news then, you can get a decent, well insulated slab down and use that to smooth the heating peak demand. ASHP will lend itself perfectly, and slab / duct cooling will be a very good friend of yours. 2x the bang for 1x ASHP bucks. 👌. Do you have permission for solar PV? Stay away from solar thermal as you’ll have an “all electric house” and nowhere to utilise the excessive amounts of heat ST would give through the summer. The PV would, however, run all the cooling FOC when the thing shining on the roof causing the problems also lends itself to off-setting the costs of mitigating against it. Focus on air tightness, and max out on insulation to suit the budget. For eg, you should be going for a minimum of 200mm of insulation under a HEATED slab. If you can’t get to that standard all is not lost, as at the end of the day the ASHP is a multiplier so for every 1kW used, you’ll get around 2.5-3kW heat out of it. Get an early design SAP / DER and also see if you’d benefit from RHI at all. If it breaks you even on the cost of the install that would be something towards the kitchen . If the EPC is v. good - excellent then RHI probably won’t be significant enough to cover the elevated ( MCS accredited ) installation. Most of my clients have been persuaded away when seeing “the numbers”.

Hi @Canoehq and welcome to the forum. Are you allowed to remove the existing slab / floor and reinstate with new? Bottom line is; can you add insulation to the slab now or will you have to beef that up retrospectively?

That's better. All the kids playing nicely

Utah Saints?

The UFH staples tend to stretch the DPM and then it still seals tight-ish to the staple. Not ever had an issue, but with liquid screed they put a much thinner ( 1200 ) membrane over the lot to keep it leak free. With concrete it's not as much of an issue as the water tends to separate out and the concrete stays put.

You and me both

That's fine. Also I'll shoot you in the ball-bag if you try Welcome to Buildhub

What about the day when you don't even have to think about that eh?

Looks fine to me. And yes, I wouldn't bother with the barrier paper tbh, unless it is required for the manufacturers warranty. I'd say you're good to go laying that directly onto the deck you have, eg no additional plywood. FYI, plywood and smoothing compound ( thin / fine grade self levelling compound ) usually only get used with Amtico / Karndean types of flooring, which will show deck imperfections through the surface if not laid on a totally perfect deck Not a consideration or concern with the type of flooring you've gone for. 👍.

Hi folks. As a moderator on this forum, I'm not exactly over the moon to see how this is going so far. Hi @Laith J. As an introduction, that was a little short and uninformative. That is what has provoked some replies. An explanation that you'd heard that this was a good / interactive information source would have been useful in your first post. Residence here is a privilege, not an assumption, so we keep this ship 'Bristol fashion' at all times, as I hope you appreciate. Lets leave any assumptions out until it's appropriate to comment otherwise please . All new members are screened before being allowed to join, and are pointed at our T's & C's whenever necessary. +1. Feel free to contribute and ask questions. If you need to check what's acceptable and what's not, drop me a PM and I'll be happy to help. wind....sailing....close..... Back to work everybody !!

Do you have a link for the chosen products? If there’s an underlay, that would suggest you’d be ok to lay directly into the P5 / Egger deck but if it’s taken any rain on and you have ‘dog ears’ at the corners of the deck boards you may still benefit from a blast ( only where necessary) with the belt sander before laying.

Thin Ufh / screed combos are quite erratic in how they convey heat into the rooms. Make sure you put the pipes at 100mm centres NOT 200mm or 150mm or you’ll have horrible over / under shoots ( room goes from cool to hot to cool to hot ) rather than the room staying comfortable. Choosing the room stats is also very important as the hysteresis needs to be 0.5oC minimum. Rotary ( thermostat-mechanical ) are utterly diabolical at running Ufh so choose well or suffer the consequences 😉

@MickD How about just feeding an MVHR fresh air inlet to the amp room to push the heat out of the equipment and into the house? 2 birds, one stone. Just feed it in at the bottom and bingo, fresh cool ( CLEAN AND FILTERED ) air input, and as the room would be positively charged you should get near zero dust / infiltration.

Do building regs shift if you have / don’t have a heated slab?

This is the kind of hint people do or don’t get. Thank you. Nick, the data is the HUGE amount of effort that went into the last poxy Brexit thread, and that data has now received more input by this one needing the same effort. Read my last. Trolls and other persistent arseholes ‘rock the boat’ and we simply prefer plain sailing on calm waters. This is a volunteer operated forum, run for the benefit of its members, seed funded by the FMG and it’s also continuously maintained by the FMG in ‘our’ spare time. Any dents in the availability we have to give to the forum are frustrating and time-consuming, and these replies are such dents. Any more ridicule will be unwelcome, and the posts that bring such content will be deleted without further notice or explanation. For the benefit of our members, ongoing decisions are not made by any one individual. Behind the scenes we discuss such things at length and move only when we have arrived at an unanimous decision, as per our constitution. We act according to our own guidelines so as to ensure all ‘reviewed items’ are dealt with fairly. Thanks in advance for your cooperation. Mods.