PeterW

You can go 100mm full fill celotex but you need to bear in mind that you need a specialist version as it isn’t easy to build in. 50mm won’t meet building regs.

Ok so ... ASHP can’t get to thermal store temperatures. You need in excess of 65-70c to have a decent thermal store capacity and that gets to near 1:1 CoP which gets expensive. Also, if you want to use RHI on an ASHP deal, do the bare minimum as your payment is based on the design heat load so if you put too much insulation in, you won’t get the payments to cover the cost of the ASHP install.

So a real fag packet : 12.5mm PB with skim 25mm Celotex 100mm light block 150mm blown EPS 100mm brick 0.17 W/m2K 12.5mm PB with skim 50mm Celotex 100mm light block 100mm blown EPS 100mm brick 0.18 W/m2K Both could be done with either insulation backed PB or battens.

Nope - standard cross section which is 300mm trench, pipe 100mm up surrounded by 10mm washed gravel and geotex wrapped pipe, or a geotex lined 300mm trench with the pipe in the centre of 100mm gravel all round. Standard perforated pipes, 1:80 fall. You may want to link the ends of the pipes together too - make either a D or a flat 8 so if it gets blocked there is always a flow.

Can’t go far wrong starting here

How long..? How far..? if it’s just pipe runs then £6/m for pipe plus £4/m for bedding. An IC should be change of £70 with lid and riser to 800mm. Suggest you bring all together into one big 450mm IC and then put a smaller 300mm IC as a rodding point just before the sewage tank.

Correct. However you’re no longer using in a timber frame building at that point, you’re using it as a full fill cavity board which is not it’s purpose Are these 3 storey or 2..? I would move the 50mm insulation inward, just give yourself a 50mm cavity as @Ian has suggested and then use insulated PB or even clad the inside with 25mm celotex and create a service void. Also you have to get through the sound tests - there is no “soft” insulation or air gaps in any of this - have you read the Robust Details for this sort of build ..??

You could try Pipestock but there prices are already pretty keen. I’ve exchanged a couple of texts with a mate who installs this sort of stuff and he said to check if you can find someone who does electro fusion welding however he said it may just be more expensive. How far down the lane is the farm supply and what do they want to run off it ..? May be worth looking at 32mm to the farm and then both of you run 25mm from there.

Uponor make most of the high end MDPE in the U.K. and it’s a continuous extrusion plant so you could buy 2000m if your reel was big enough. Do you know if you can have a 32mm connection as most are at best 25mm and are restricted to a 15mm water meter orifice at the stopcock end.

Right ... 100/150/100 with blown graphite EPS, 400mm loft insulation and decent (ie 1.1 or less) windows and you will be getting toward something workable without the solar. Your big issues will be power - diversity on 3 x 10kw electric showers plus panel heaters etc means you’re going to need to run 3 mains connections. What is the water pressure like ..? Again, 24lpm is your minimum flow so you’re heading toward 32mm main territory. Are these one bed flats ...??

@80BSY where are you in the UK as this may make a difference to the answers.

There are some pretty nasty acids in cola - this is what is in lime scale remover and most of the cheap toilet descalers.

Welcome ..! Plot and plans are a good start - has the build been designed to be to passive standards ..?? If you’ve got plans it may be good to post them as it can give an idea of what’s achievable. Any construction method can be used to meet passive levels - it’s the detailing that causes the issues later on and this can happen with anything from blocks to timber frame or ICF. Sadly there is no golden bullet ..!!

I’m with @Cpd on this and would go for the Rutland one. Their stuff is pretty well made and the benefit is the chuck is much bigger - 16mm is a hefty drill bit however it also means you can fit stuff such as broaching cutters if you wanted too.

You're missing two things -the outer skin or finish on the ICF, and that mass concrete weighs a lot more than blockwork. C25 is around 230Kg/m2 at 100mm, medium block is 110kg/m2 and lightweight block is 60-70kg/m2. So if you had a 150mm core it would be 345kg/m2, where a pair of medium weight block walls would be 220kg/m2, or around 36% lighter than the equivalent ICF. Also worth bearing in mind that ICF has to be around 80% thicker for insulation purposes than PIR - again, this is cost vs thickness decision. If the outer finish has to be brick then the argument for ICF is pretty much lost unless you go with a slip system that will be even more expensive than brickwork.

Ecover products are supposed to be tank safe - check them carefully in the shop though as I think one of them is only use sparingly.

You’ve used it on a porous surface that will pull the moisture from the sealant back into the board. FWIW I hate that forever white stuff as it’s not a true silicone and it skins too quickly. If you’ve got Mapei grey, I would get a tube of Mapei white as I never have a problem with that.

I’d put a gravel board around the edge, weed membrane and 20mm gravel. It’s free draining and cheap, and you’ll hear someone trying to drag anything away ..!

@Sue Bthese are £20 each - half the price of new.

Try Meridian - they have people covering that area and really responsive. http://www.meridianconsult.co.uk/

Are you drilling 89mm studs as there won’t be enough meat left of the timber - less than 7mm each side of the hole.

@Russell griffiths it’s an online service now I think that does that. @scottishjohn you could try National One Call who do the dial before dig service that contractors use. Looks like SW are one of those companies that charge a fair whack (the £57 in your link) for plans but NOC say they are the cheapest. National One Call

If you’re after full loads @Triassic then find a CCF. Part of the TP group and just do board etc. I was surprised at how well they priced a job - was within same ballpark of local merchant but difference was it was all offloaded with a Mounty and put exactly where it was needed rather than having to hand ball lots of board and insulation.

That’s like the companies a lot of solicitors use for drainage but just relating to water and drainage. Their full search is £540 which is eye watering though ..! There are cheaper ways to find gas and electric out there. I’ve also noticed Virgin Media have stopped providing their network info - do wonder if that has anything to do with them doing more commercial and secure networks.

I prefer Brett Martin but there isn’t much in it as @Nickfromwalessays although Floplast isn’t the best when it comes to fittings tolerance. I use the same supplier as @Onoff has linked to - add up what you need and see if there is other stuff such as ducting as they do volume discount pricing.