Nickfromwales

As per my PM, I think sistered 5x2 C24 glued and construction-screwed to the existing will be crazy strong. You could even add perpendicular timbers behind the uprights like strong backs.

You don’t use the FB’s throughout! One steel across the garage door opening, one FB mid span, parallel to the steel, a wall plate on the back wall, and then timbers stitched in between. Looking at the pic, why not just use steel to form a T and then span from centre out? However......... As we are in fear of over-engineering this ( ? ) why not revert to the earlier suggestion of a 5x2 each side of the bottom of the trusses? So bloody simple, and if you’re going to board out and form I deck you there, glued and screwed, it’ll be rock solid. Every time I do structural joinery I look at it and think to myself “that’s way over the top”, but get an SE involved and that’s what usually happens ( as they have to professionally underwrite that solution ) so do you really need this degree of technicality for this project ?

What centres, what?

I did 6.1m with SE sign off for an attic conversion, and that was with the flitch, and that was taking the head of the stairs as well. Done in 7x2, sistered, plus steel fillet, drilled and bolted every 400 IIRC. Stronger than a strong thing, like near zero deflection, and the first time I'd heard of them too. Then used the same principal to reduce the profile of the huge 12" purlins down to 5" flitch. HELL of a lot easier to get up 3 stories vs steels, which would have had to have been done in sections, plated, and bolted up. Hired a Mag drill for the day, and it made drilling a breeze. 3 man job at that length as that steel will twist, flip and fly out of your hands quick-as, and good luck trying to stop it in mid-air.

Vertical drops are near inaudible, but changes in direction do cause noise. You can mitigate against the high frequency sound by wrapping the nuisance parts in sound deadening mat ( dynamat ), the bituminous stuff you see in car panels and under the kitchen sink. eg. That and as much acoustic rockwool batt as you can stuff in there. I wouldn't try for the utility as that's a long way with not much of a fall, especially if it's Pozi-joists?

If the fuseboard was relocated, is it now further than 3m away from the meter? What's the supply fuse rating?

Dead man walking..... What I would recommend is a small tiled boxing in between the existing boxing-in and the bottom of, say, a semi pedestal that had been, perhaps, bastardised by an angle grinder ( if that's what it took to keep the boss happy....... ). We all salute you!!

Ok, so when do we move from ‘gentle nudge’ to screaming “that will look crap”? +1. But would need to have a cavity at the back so you can leave pipes in situ and cut out for that boxing -in. Beware ones which are flush to the back wall.

Beauty is in the eye of the beholder....

With one hand on the angle grinder, ( fitted with a continuous rim diamond edge blade rated for porcelain ), and the other hand on your balls. Disclaimer : Holding balls is optional, but best to have both hands on the grinder. Slow and steady will do it, expect the porcelain not to like being cut.

Then deffo do not go for the semi-pedestal . IMO it'll look daft having pipes disappear into it after them being exposed below. I have cut a LOT of porcelain stuff in my time, to do things like this, but it's very unnerving and some stuff didn't live to tell the tale ?

Usually OSB3 these days for that?

I believe its because the monoblocks have a far less convoluted initial start up and run time so the split units tend to fire up 'for a good reason'. From the various suppliers and installers I've spoken to, the split units have to be justified for that choice of 'weapon' to be warranted. That's what I've picked up on from having many of these types of conversations over the years anyway. As always, anyone considering such an install should do their own due diligence and make sure the chosen equipment is fit for their particular instance rather than take generalised information from anywhere else. My experiences of this type of unit go back 2 years, and I see HP's have come on quite a bit in that period.

Buffers can be strategically positioned also, so you could get the much loved 'airing cupboard' to maximise on the 'waste' heat.

That's my understanding, yes. Not really as the buffer would only be inline with space heating and not the DHW, so adventitious heat given off by that vs nuisance heat. Very difficult to offer more to that post as we do not have client / dwelling specific parameters to hand.

Telford offer that with a lifetime warranty, and its 100% stainless. But yes, it was installed to be removed and replaced with spanners and a cordless drill in half a day or less.

Does it 'max out' when reheating the cylinder Dave? Whats the noise level in DHW mode is my point, with 5kw vs 300L?

Split units are a totally different beast to a monoblock, so everyone should keep that in mind and take that with a pinch .... Does show that the MCS scheme is good for that type of instance, but hard to understand how that ever became a problem because being an accredited MCS installer ordains you to do due diligence, way before executing the installation. Perhaps that particular install is simply missing a buffer tank.

I'm tired. Bugger off.

He means an open vented one like the Telford Tristor No need for discharge pipe then as it has a manual fill header tank, eg not pressurised, but a has a mains pressurised instantaneous DHW coil sat in the heated water to give mains pressure balanced DHW and plenty of it. Only ball-ache is it has higher standing losses which would be exaggerated by the lower external temp outdoors in winter.

It would need to be a big attic to get that upright and to bear the weight in that one spot? Is it too late to get a horizontal tank and put it up the attic? That helped spread the load out and keep a central walk through clear.

If it’s been surveyed first, a good plumber should do that in a day. So £160 plus materials I suppose should be ample. Will the tank have to have a timber plinth constructed to sit on at its new location? If so, factor in costs for that too.

As above. Inverter to take DC to AC, diverter to send it to specific loads at specific times etc. Yes. The reason a Sunamp has a mains 230v feed from the CU for the controller, and then a separate feed to the immersion ( via a contactor on the controller PCB which operates as a gate ). Lots of electricians were getting this wrong early on and some ended up blowing the SA controllers up.

And a system ( if not second hand from the outset ) that lasts 25 years minimum will therefore give 'free' electricity out for the next 15 years minimum. Most are warrantied for 25 years, Solarwatt for 30 with a 30 guarantee as well as warranty. The cheap stuff is likely to fail, so avoid the cheap seats where budget allows IMO. It's down to whether or not you can utilise it and not waste sending it to export eg maximum self consumption.

Unless your array is north facing, I cannot see how PV would be a bad thing?! Any PV company will have to give you a survey and forecast of performance / cost / break-even point ( based on deemed % of self consumption ) / and RoI numbers for you to consider. Have you had a proposal yet? If not, it would be a good paper exercise IMO, and should be free.