Nickfromwales

Anything you want / need basically. But for ducts and small bore services for my needs mostly. Can be letterbox shaped for transfer grilles I’m sure.

You can have penetrations made in the steel before it’s installed. I do this all the time on my M&E installs, very simple to achieve.

The system needs to be flushed and treated, there’s a worrying amount of ferrous oxide present! This will routinely knacker ever new AAV that you install, so don’t waste time with fitting any more replacements until the cause for their failure is resolved. I wonder if this was ever treated with inhibitor?! How old is the system?

It’s pointless going manifold to manifold, as that defeats the whole object imo. Having higher volumes of ‘dead legs’, before basin taps in particular, means that you’ll waste a lot of water/energy getting premium temp (hot) water out of high-frequency/low volume outlets (if there’s no hot return circuit). Not a concern for baths and shower, less of a concern for kitchen/utility taps, but defo a sticking point with basins where you just want to flick the tap on and wash your hands. Stick with Hepworth, it’s all I use these days and is simply bombproof. Where failures occur is when someone installs the pipework and scratches the outside diameter linearly causing leaks/weeping joints. If there’s a few turns and twists the simply install offcuts of 25mm flexible conduit at these points and draw the pipe through them; particularly helpful if doing this on your own (single handed). These can stay in to allow some movement if necessary, and this should be considered for longer hot runs where the pipe will expand/contract a little with temp changes. Without distances from the cylinder to the outlets, and what they do, it’s impossible to advise on pipe size what he said

Not the end of the world tbf, but I’d install 15mm sound block plasterboard to all the internal faces of the outside walls to combat acoustic pollution/nuisance ‘noise’. PIR does very little to promote a ‘quiet’ house, even with 140/160/180mm of the stuff sound still travels quite unsympathetically (assuming SIPs type construction?).

The house doesn’t look overly complex at all. I would simply oversize the MVHR system slightly to allow for effective purge ventilation, and see if that takes any other mitigatory requirements out of the picture in one swoop. I recently chatted with Nicholas Vaisey (CVC Systems, Oxford) for this exact reason, and for options to navigate this. These guys do all of my self-build clients heating / heat pump / hot water and MVHR, design, supply (and install (when I am too busy)) and this methodology provided a simple, practical, cost-effective (and elegant) solution in one box. This was considered in a set of proposals I’ve just done for a mass home builder, where I was drafted in to provide pre-construction M&E / plumbing design specifications for 2 large sites; Part O raised its head and everyone on the project just became disorientated as they weren’t used to dealing with it, clearly, with technical staff seeming utterly clueless tbh and were obvs out of their depth there! Doesn’t bode well for anyone buying one of their sausage-factory ‘boxes’….. If the house is having MVHR anyways then economy of scale says this would be the easiest and cheapest route, eg to slightly over spec at the design level at minimal cost-uplift, adding in an assumption that slab cooling via UFH / ASHP is already possible / being considered? Combatting audibility (at higher airflow rates in the summer) with some extra thought going into the design for the distribution ductwork needs to be factored in, but at that point I would defo rule out a series run setup and go for radial. What is the target airtightness score that you are aiming for? I think AT is more important than insulation as you can have a foot of PIR, but with high infiltration rates, and still see a cold house each winter.

It’s very time and detail heavy, and as said if you input things incorrectly, accidentally, then it’s not worth the paper. +1 to getting it done by someone who’s going to know the pitfalls and get you an accurate outcome. My 2 cents, but where do you think issues will arise? Are you super insulated, airtight, and lots of glazing?

The more detail you can provide the more accuracy / reduced ambiguity there will be in the quotes. Mark as much as you can on the plan, including TV coax and CAT6 outlets, CCTV, outside lights etc and then ask the electrician to review and comment before quoting perhaps, as they might make some suggestions to better the end result.

UFH and rads heat up / cool down very differently so should defo each have their own stats. Mixing valve on the UFH will control flow temp into the floors but you may find running at 50°c in winter will brighten up the rads significantly so you will then at least have that control / option to do so. If, however, now running the UFH off a controlled setup why not downsize the rads and turn the flow temp of the boiler up to 55/60°C? I’d favour smaller rads obvs, if it was my home.

Is it a warm roof?

2 channel if it’s a Combi.

I never omit the mixing valve on an UFH manifold, even more so when it’s a high temp heat source such as a gas boiler. Fitting a pump on it is then a requisite (as mixing valves need to be sucked on vs pushed through by a pump) but again if the rads offer a path of less resistance to a single boiler pump then the most resistive of UFH loops will get ignored when both the rads and UFH are running simultaneously (more so when the system is getting the house up to temp and all require ‘full flow’. 45°C may be fine for the UFH flow temp but we couldn’t say much more without knowing the screed thickness / floor insulation thickness and more.

Less haste = more speed, and then no expensive fixes

The only real issue with rising penetrations through a slab is if it’s a block and beam. In this situation you need to avoid a beam. Structural engineers will have some “say” if you have all ducts together and it requires steel reinforcements being re-jigged, but a little bit of pragmatic pre-planning and dialogue will resolve this in a day. Tell your builder that this will progress at your pace, and will arrive at the end result that you want, and he will have to slow down accordingly.

I’ve just moved clients into their new build home, and at the outset of the entire project when we had to redirect overhead 3ph supplies that spanned the plot we found a chap who was ‘no win no fee’ that handled the DNO application on the clients behalf. His “promise” was to get the price discounted and he’d bag 20% of the sum saved. This resulted in an £11k quote being reduced to a net cost to the client of £6k. Well done that man! If you can think of it, someone is making money creating a solution around it! 🤷‍♂️

These things are easier to do than explain lol You can set the tray in 3 sides around with the mouth being on the sacrificial sides, eg left/right/rear, but the issue of wet testing/proving the waste and pipework isn’t leaking remains, I guess? It’s common practice, for me anyways, to have the sump of the trap set into adhesive or captured by the leveller/backfill medium, just given me seeing these crack and fail over time when unsupported. If the manufacturer doesn’t specifically state in the MI’s that the waste atop (what you’d step on when showering) can take your weight then reverting to my methodology would be ‘wise’, but if it says you can throw some shapes in there and it’s bombproof, then take with a pinch.

Hi. Busy times sorry! Interesting mix with the steel tray, but they’re pretty robust tbf. Firstly pack a couple of handfuls of dry tile adhesive where the waste elbow joins the underground pipe. Then bench 270° around, sides and rear, and also set 4 pads of tile adhesive about 8” away from the trap, then lower the tray onto that wet bed, level, run a fair bit of water into the tray to test the waste and trap for leaks, and then leave for 24hrs to cure. At the front you’ll need a ‘mouth’ cut into the concrete floor so you can see under the front edge of the tray, firstly to allow you to look under when wet testing, and secondly to back fill. Once the above is done you’ll be set in 2 sides and rear and dry, plus around the trap, but the trap won’t be supported. Mix up some Mapei builders screed (flexible screed with fibres, Screwfix or tile merchants usually carry it) and pour it into the mouth you’ve left using cardboard as a funnel. Fill it until there’s a good amount under, possibly less than 2 bags by your pics, and then the trough you’ve chased out for the trap and pipe work will all flood with the leveller. This will support the bottom of the trap so when you stand on it accidentally, particularly with your heel, you won’t have any movement. The dry adhesive will stop any leveller going where it’s not wanted/prevent its loss at that junction. Clean and seal around the tray with CT1, open a beer, and call the tiler. 👌👍🫡

Don't be shy, the last M&E spec I delivered had about 17 different ducts for everything. Makes life soooo much easier at 1st fix etc, and for any alterations you may want to make downstream.

The mixing valves do die off with old age. Just put a new one in and you’ll be in the pub for Friday 15 years is a decent stretch for a part that’s constantly moving / adjusting etc. Do you have a magnetic filter in the system? If not, I’d add one when you change the valve.

"Refereeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee". 👉

Say what?! Is that a Scottish thing?? Have you had too much Sudafed max strength tonight?

We'll all just go and kill ourselves now ok, thanks

Then your heat pump will be quieter than a congregation, when the vicar says "does anyone know of any lawful impediment".... lol

All depends upon the fabric quality and energy efficiency of what you replace the existing dwelling with, to be completely frank with you. The device choice argument is moot, if the agreed option is less economical to run than gas one you turned your back on. You'll notice that all the big hitters that make gas boilers are all selling new ones as 'hydrogen ready', if requested. Why do you think they're doing that? If this is not an uber-well insulated/airtight dwelling with eco 'super-credentials' and MVHR with heat recovery et-al, then stick with gas. If you fit an ASHP and it's not a good fit for the dwelling, you'll be burning the planets resources at the same rate of knots with an ASHP anyways. Remember with gas, the network will NOT be going away, only the product coming out of the end of it will change (in our lifetimes for sure). If your heat pump ends up with a CoP of 1:1 then you've basically heating off direct electricity, on demand, and the planet is doomed. Oh, and stop considering your bloody neighbours so much. They'd shit on you in a heartbeat, if it worked out in their favour to fit a noisy heat pump to their home, ffs. Tell them we said "hi". FWIW, a good quality (even a cheap) heat pump will be as quiet as a church mouse coughing into a hanky. If, however, you fit the same heat pump to a dwelling that doesn't compliment it, then it'll be getting an ASBO PDQ.

Concrete screws want a 6mm pilot hole, but with concrete blocks you can pull them loose by over-tightening a short screw. 50mm or 60mm would be best. If you don't just save shitloads of wasted time and effort and gas nail them with a Spit gun.........