PeterW

I’d ditch the combi, fit an external Grant boiler and a 500 litre thermal store with an immersion and dump the solar into the TS set at 85°C. Summer the PV will keep the hot water going fine, winter the boiler will do the grunt work. No UVC to worry about and oil boilers love long burns so a TS is ideal.

Pump won’t fit in a stud wall.

Buy yourself one of these kits for £60 and do it yourself. You’ll be done in a weekend and can say “I did that..” Bricky Pro - The Bricky Tool / Adjustable to build all standard wall sizes 4", 6" & 9". https://amzn.eu/d/6MCgJhq

Hallmarks of a sticking float valve and one of the jets full of crud.

Loads. Boards are 12.5mm, tiles no more than 8-10mm each side plus should land on top of the tray so you could go to 930mm and have wiggle room to seal the tray properly.

Suspended floor my owd fruit so he’s got plenty of room for suspended insulation under the floor/joists etc 😁

Yeh - I use these if you want a really tidy look, but don’t forget to insulate the MDPE first and centre it in the rubber outlet using some more insulation offcuts. https://www.roofgiant.com/guttering-fixings-accessories/deks-110mm-universal-waste-adaptor/

Pug mix works nicely and you can strengthen the floor using 18mm ply/chipboard and then cross batten with standard roof battens at 300mm centres, glued and screwed to the sub floor. This leaves you with space for 100mm spacing for standard 16mm pipework. A semi-dry pug mix over the top then capped with VCL and 12mm ply screwed to the battens will give you a 55mm build up. If you suspend the insulation from below using netting or even cheap landscape fabric it will make it easier to install.

I’m not questioning that however you’re using a product that has a low r-value and will need to put significantly more heat into the building through whatever source you choose to offset the low thermal performance. The eco credentials of the insulation become pointless if you need to massively increase your carbon footprint to heat the property ! The whole lifecycle cost of the products gets ignored and the sustainability argument goes out of the window - we have regularly had this argument with clients who want net zero properties, and we have to get into the lifecycle cost of materials which is probably more important than the baseline initial “environmental” cost of the product itself. If you have a limited insulation thickness on the front wall then consider a better performing product to get at least a BRegs minimum score for the element and then use the wood fibre elsewhere.

yes - an overlay system at delta 15°c can deliver a maximum of 65W/m2 using spacing of 150mm which they are fixed at. I can increase a rad to deliver using type 21/22 rads that can put around 4 times that into a room using delta 50°C if needed to reach the heat loss required. Using what method ..? Hygroscopic insulation is irrelevant for a solid wall dependent on the outer final finish. A 9” solid brick wall isn’t breathable unless you use lime render outside and a full lime based solution inside - at that point you would be better using a VCL and 65mm PIR internally and increased ventilation - cheaper, quicker and easier.

1905 is solid 9” wall even with insulation (why wood fibre ..??) , so you’re needing in excess of 150W/m2 which you won’t get from an overlay system so you are better off on radiators. 5kW heat pump will be running 24/7 in winter unless you’ve sealed every hole in the building and like 15-16°C room temperatures. Have you done a proper heat loss calculation for the building and worked out the real numbers ..?

Ok slightly lost now as when asked about insulation you said this : So are you saying you only have 4” joists and the rest is an undercroft ..? How are you planning on suspending 200mm of fibre insulation ..?! You also don’t need to notch the pipes - just drop under them at the ends and tack to the bottom of the joist with a pipe clip. OK so unless you lay the pipes perpendicular to your joists, it creates a crack plane along the pipes. There is also a difference between routing out a few pipes and using an engineered product. This stuff is also foil lined in the grooves, only fits 12mm pipe and is eye wateringly expensive. It’s a last resort when nothing else will work for very low profile jobs. To fit Marmoleum or any of the Lino type products you need a seriously rigid floor - that means the ply has to be glued and screwed to the joists, and then you need a decent compound over the top if you’re looking to level between floors. It cannot flex or move or if will crack and cause issues. I would look at this differently - what is your limiting factor on height you are working with, and how old is the building you’re working with ..? What heat output do you need, and what other insulation have you got in the building fabric as all of this is a contributing factor. Without all that information I can’t suggest anything other than using a spreader system although even that has its limits if you have high heat requirements. What the manufacturer of the boards that use 12mm pipe won’t have told you is the output is 20% lower per square metre, so you need either more pipe per metre or a higher temperature. That then limits your floor choices as engineered wood and Lino both have maximum flow temperatures.

That won’t work. Your floor will break as you will have routed out 2/3rd of its thickness and no amount of ply will make up for it. Why not fit spreader plates under the chipboard and then you’ve got a flat surface to start from.

I’d be surprised if the plaster is out by that far - looks like walls/framing wasn’t square before it was boarded and skimmed. Edge beads look like they weren’t tacked on properly and again, if the corners were out of square then they will pop. Some of the issues are down to the spreads but tbh that looks like they didn’t start with the best of situations.

It doesn’t … flow rates are so low it’s not capable of huge heat transfer. Is that over 6mm ply ..? That will crack and move. What’s between the pipes ..? And who’s designed the bulld up .?

Shouldn’t have been poured with a vertical join unless it’s got rebar or steel dowels in the join. In reality it “shouldn’t” move but I would be putting a couple of 215x140 1200mm concrete lintels over the joints and building off those - and hoping BCO doesn’t notice !

@faby get some decent 4x2 (CLS will do) and run it down the side of every joist that you have to adjust the height on and glue and screw it on the side. It will both give stiffness and a wider landing for the ply joints. D4 glue every joint - you need 2mm max between boards but try and land all joints on noggins. If you have access from below then even better - lay the boards then glue a 4x2 on flat below each joint and make sure it’s tight to the bottom of the boards. What is your final floor finish going to be ..? And I am assuming you’re also using decent sound / heat insulation under the ply in the void too..??

It’s only 23” tall …. That would stall the moment it hits something 1” thick never mind 3”..!! Find your local hire place and get a decent one - I pay £75/day for a tracked Lindana TP160 that will swallow 160mm trunks and spit them out as chips .. I reckon we can clear about 2-3 cubic metres an hour of stacked timber. Even a baby Timberwolf will do 100mm with ease and they are £150 a week to hire.

6m doesn’t need a HWRC - if you had 15m runs to basins (again they can be 10mm) then it’s different.

You’d be surprised the flow at 3 bar pressure from 10mm ..!! It will be fine - probably less than a litre to get to hot.

Nope you have to limit the water to less than 45°C (IIRC and nowhere near my regs books) at a bath tap but there is no limit on where you do it. If you do go the HWRC route too, no point circulating water at tank temp constantly. HWRC I would put on either a timer or proximity for a bathroom but just run kitchen and utility in 10mm as the losses are minimal then. I’d be storing at 48° from an ASHP boosted to 65°C via E7 if I wanted additional capacity or 85°C from solar via a dump controller.

Only in commercial installs, not domestic. You don’t ..? You install one pretty much at the outlet from the UVC and blend down there.

why would it..? If it’s a new WC then fit a stub stack and AAV and nothing comes through the roof.

At the point of PP being granted it changes usage class It does though give you the chance to go for an insulated raft which may not cost as much as you think and has numerous benefits for insulation purposes. Kore is one brand, there are others but a lot can be installed on poor ground using a compacted sub base very successfully.

Doors haven’t been adjusted correctly. If this is a pair of French doors then you adjust equally to bring them together, not from one side. The gap you are seeing is because the cams in the opening door are not engaging in the frame at the bottom - it means the door isn’t parallel to the frame, and/or the door isn’t parallel to the other door. All of the above is a 15 min fix for a decent fitter who should re-adjust the doors and they will be fine. You do sometimes find they will bind when warm but that’s because the doors expand in the heat. A scratched unit (especially one beyond a seal) needs replacing.