Ben Weston

Thanks for the replies :-) Yes, in hindsight this would have been a much better idea. Unfortunately, floors are all down now so we have to deal with the MDPE as it is. I'd be happy to replace the stop tap – the JG one is 220mm!!! It's why I'm concerned about how I fit it all under the sink! This definitely simplifies things a lot, thank you. It also looks like I might need a drain tap directly after the stop tap but I've not been able to find a single 32mm drain tap! Is this the case?

Hi all, New build. We have 32mm MDPE coming up under the sink. From the sink, we need 15mm feeds (Hep2O) to the kitchen appliances and a connection to the 25mm MDPE pipe that goes to the rest of the house – water cylinder, heat pump, bathrooms, etc. I'm trying to simplify this but am struggling. It's a LOT to fit in an under-sink cabinet currently. I've attached a diagram of the simplest way I can think to do the pipework but I know it's not right. Can anyone much cleverer than I advise how to take a 32mm MDPE and terminate to 25mm MDPE and 15mm Hep2O?

Thanks both - really helpful suggestions. I will make up a test board as suggested and see what it turns out like. Noted also on latex; this was recommended by a few others to me too. I suspect we'll end up going a latex SLC route with LVT or Karndean/Amtico on top.

Ah, thanks Alan. I'm looking at this: https://www.screwfix.com/p/no-nonsense-cement-based-levelling-screed-20kg/116hu Good to have your feedback on that one though, thanks.

Thanks both. Interesting that you found it “crumbly” and difficult to get flat @Alan Ambrose — was this their standard SLC or the slightly more expensive concrete-based one? I've only seen good reviews of both. @Redbeard Might it have been the bitumen base that contributed to the lack of longevity? Genuinely don't know. We'll be pouring the SLC onto C35 concrete.

Reviving this again: we have wet UFH upstairs and had planned to put carpets down but the more I read into it the more I think it's not a great idea. I like warm, squidgy carpets in bedrooms but if it stops them getting nice and warm in the depths of winter, I'm not so keen! I presume an LVT wood floor would be far better for heat transfer with the correct UFH underlay?

Hi all, We quite like the matt/polished concrete look and there are a few concrete-based SLCs available (Screwfix's own has come recommended by several people). Our current plan is to put the SLC down prior to LVT flooring but I was wondering if a concrete-based SLC can be used as a finished floor? If so, is there anything particularly to look out for?

Brilliant, thanks all. This is very helpful. On your polished point: I'd actually love to polish it and have that as the finished floor (not mirror finish, just matte and flat) but think that's beyond my skillset.

Yes that's true, they are. Doesn't that cut need to go all the way down or is it just to encourage any cracking in pre-defined places?

Thanks all. We're not going for a screed on top — the concrete slab will be floated up and any minor bits sorted with a self leveling filler (though obviously hoping not to have any!) Flooring to be laid on top of that. We were going to mesh the doorways but otherwise leave the fibres to do the reinforcement. Cutting down the slab might be a bad idea for us as we'd also go through the UFH pipes 😆

No, not a structural slab. No load-bearing walls on it. As you say: traditional foundations and slab poured between. House is already built — floor is one of the last things to go in!

It's not screed, it's a concrete slab. Build up is sand, DPM, 200mm PIR, DPM with UFH pipes, slab. So it's a traditional C25 slab.

Hi all, Our ground floor build-up will have the concrete slab at the top (poured over UFH pipes). The area of the downstairs is 105m² and the slab going down is 135mm fibre reinforced. I'm conscious we should probably be adding expansion joints in all doorways and also at intervals in the big rear section which is a 60m² room. Question is: what do we use for the expansion joints (I'd seen Fillaboard?) and how do we add these so that we can pour the full 105m² in one hit?

Hi all, We're doing a significant renovation of an 1870s cottage, including a two-storey extension that over doubles the floor area. I've only recently become aware of Part E. It hasn't been mentioned by our architect or BC. In terms of the actual construction, stud walls have been made out of 2x4 and will be packed with rockwool insulation and boarded with regular 12.5mm plasterboard. Is this enough? The first floor deck sits on Posi-Joists and we were going to pack this with as much fluffy as we can fit in there (about 200mm). I'm concerned this won't be enough. The main wall between the cottage and the new extension is a typical solid wall construction which will be rendered in lime both sides. Nothing more will be added to it; is this enough?! Hoping someone can clarify Part E and how it relates to what we're doing.

Good to know, thanks. You're in our neck of the woods too - we're just south of Norwich!