saveasteading

Begging your pardon. I'd misunderstood your intro. I now see that the extension is for another time. This is a small building in the garden. SO: the tree will affect it. The ground will shrink in summer and expand in winter by 10mm or so. Does that matter? I'd say you live with that and any minor damage it might cause. So you can use 1m deep footings and not much damage should occur. I'd say that is OTT for this building. Or slab with 400mm downstands and accept a bit more risk. so go with your 600 depth, and 400 wide if you can fit in it. To minimise ground shrinkage make sure the rainwater off the roof is dispersed very adjacent so the tree gets it.

Yes as it is part of the house. Make it separate and it isn't. Says who? Or do you mean you haven't contacted them? Perhaps make it an outbuilding with a passageway link. I think I'd regard that as not affecting the house.

That was one of the questions I put. They knew nothing. Such screws are a possibility for a garden room, especially if you want it raised. Also for a temporary building eg a beachfront shack. For an extension it must perform the same way as the house. It needs building regulations, thus an SE. Tell us more. What type of tree and the distance? Is the ground clay or what? It would be interesting though to get more info from these screw suppliers.

@Jadhacha what Are they charging for these screws? I agree with @Nickfromwales unless these are £20 each. I've had a chat with a screw supplier at a construction show. . They didn't appear to know anything so I think were franchisees.

That's so simple and now seems obvious. Ta. No brilliant idea on the hockey stick. It's all training for me I tell myself.

so should i turn off that rcd, and/or the one in the consumer unit, before doing any more? I have stupidly forgotten to put the cable through the hockey stick. So not a lot achieved! If it was a straight pipe i might slice the length and insert the cable, but that wont work with the bend.

Basics question. I turned off the circuit yesterday at the local switch in the house, and the relevant circuit at the consumer unit... I think it only supplies this one cable. I disconnected the box to change to a better one. That went well, and the metal gland is solid. No sparks or drama from the now exposed cable. Meanwhile, the primary rcd tripped in the house. How can that happen if the power is off?

Would it not be much less disruptive to either hire an insitu sander machine, or get it done? A big push-along one for £50/ day. Or a specialist would be quicker and better esp around the edges.

For interest. I've found this connection box in my stores. It seems to be very classy with 3 screw-in sleeves with integral and tightening seals. The box back is completely in one piece of moulding, and the holes are made by tightening in the sleeves, whence the knockouts break off. Also a connector block. It is made by els Spelsberg, and also labelled Attema. New names to me but the build quality (and attention to detail) is astounding. There are also 2 sealing grommets stuck to the front plate, presumably to seal the screw holes. I cannot figure out what the rubber strip joining these grommets and extending to the rim seal is for? PS. Ive found it is available at SF for £8.99. But it is described as "unbranded".

Would the cost be much? I haven't looked. The delay is an issue. But you've got the existing PP and could get started on preliminaries. If memory serves me though you don't start on claiming the vat benefit part way through. 20% can be a lot.

I'm pretty sure it is worse than that. It's knowing and understanding so little that they are unaware of their own ignorance or other people's skills. What other horrors lie in their previous jobs?

You must not delay this. What if he starts to cover that work up? Or the worst scenario is he does a runner. It is probably all sortable but for a few£k. Removing and replacing much more than that. Ask him politely how he is going to sort it. And instruct him to adapt the scaffolding.

They are not as flat or planar as might be assumed. I would still fit battens horizontally. Render isn't my preference for this structure really as it is likely to crack. A steel portal frame is designed to withstand the wind but permitted to move quite a lot. OR you tell the designer and they make it stiffer at your cost. Timber cladding would move with the building. Self supported or using the columns? if the latter they have to be designed for it now.

In which case it is totally unacceptable. 1. The beam's web should not be load-bearing onto the support. 2..The beam is completely compromised and is now understrength. 3. It needs a padstone. @boxrick the works must stop immediately. Remedying this is likely to be complex and costly. Who is involved professionally other than the builder? do you have a contractual position with any of them? A formal complaint must be registered with your builder, in plain English with pictures attached, or with technicalities if you have an advisor. remember that the BCO is not a quality control manager, and will have constraints on what he can say. Who engaged the BCO anyway, You or the builder? If you, then I would still have a word with them. BTW That knot is massive and compromises this timber... I'm surprised this got sold. Web on block.

The circuit/ fuseboard/ RCD etc were all replaced professionally when we moved in. However this cable is off an existing internal circuit. When the old cable that I am replacing used to cause cuts in wet weather, presumably a fault underground it could trip at any one of three trips. This tripped at the RCD which carries the whole house circuitry. I could take pics if that helps, and avoids me using the wrong terminology. That is not the plan. If I can get this to work as is, then I will proceed and change the old cable within 2 weeks. New cable in trunking , up into the dry and spacious attic and do a new box connection there. The existing cable I assume to be sound where it is indoors. I am now thinking that @ProDave 's point of the old cable shorting, and likely to be caused by the bend I've put on it (it was all working except in very wet weather). So for now perhaps to just replace a couple of feet with new bendy cable, and keep the old one straight. I should say that I did ask a couple of electricians to do this, but they have been 'too busy' for 6 months now. For obvious reasons they'd rather do new, clean work than this sort of thing. All decent small contractors are fully booked and turning work down in the SE. Any that are available will likely be as good as me but less interested.

Its not completely clear on the photos. It looks as if the beam isn't a beam any more, reduced to a T, almost to a plate and all the load is sitting on the web. But perhaps back where the beam remains complete, that part is sitting on a wall or plate? In which case the remaining part has become an oversail and not structural. Even then, it should probably be on a pad or plate. Is there a side picture of that?

Yes I've even got the conduit ready. The existing cable ran underground for 25m then up a pole to a 500W. That must have been pushing its capacity. floodlight. I changed that to 30W. It now supplies an electric gate which is quite low power. I'm thinking an outside socket would be a sensible addition for gardening but perhaps also car charging..... slow only. So I'm thinking the cable should be bigger than smaller. 2.5mm T&E ?

I am. I thought I'd do it in stages. For my education, why is T & E wrong in principle?

This is the old cable, coming from the attic, then was into the conduit bottom left. It did feel a bit stiff as I bent it around, but attributed that to many layers of gloss paint. BTW I am aware that the wall needs painting and the corner needs a new block. The sun is doing a good job in exposing an ancient layer that was painted over dirt, well over 30 years ago i think, so I'm letting it. The cladding was about 1930 and still has a resinous smell when cut. It's been overpainted thrice in my time here. The first by professionals who i think only prepped when being watched.. some failed in a few years. The second time by 3 steel cladders waiting for the next job... lasted well. Third by me in lockdown... and that has stayed put too. I'd like to make the corner with 2 splays out of one block of wood, rather than rectangular with 2 wedges added. But it would be a big lump of wood and I'm not sure I have the skill. Hence years of not getting round to it.

For me... have the steel z rails for the walls (pedants corner: it is only called a purlin if it is on the roof). Then fix 2 x 2 timbers vertically, and cement board over them. Then render. There isn't an advantage in cladding panels other than if insulated, as I wouldn't fix cement board direct to it, but would fix horizontal timber first. Ohhh, and metal cladding would provide a slightly quicker enclosure if a few days matter.

3 cores

Could it be that the old cable has failed in flexing it? It has been there for the over 30 years I've lived here. I was going to change it later but perhaps should do it now.

No, it is is practicality. Decades ago, hilti guns were standard and almost hitched to steel erectors' belts. Since then, other options have taken over: less macho but better in safety and effectiveness. Powerful battery drills being the main change, but also screw technology. For the erector, this means a drill can be carried to awkward places with no trailing wires, and drill then screw. As the Engineer and contractor it resulted in safer working and a much more certain fixing.

If you go on the James Jones website there is an interactive joist span table. You have a wide span and must accept deep joists. From it you can see different joist specs at different centres. At some stage they can end up so close together with such wide flanges that it is nearly a solid floor. Or use a steel, and hang the joists in the same zone.

For a few mm, Tek screws from a big name are expensive and worth it. Heavies I recall is the term With a single use blade they get through 2mm easily in what, 20 seconds? It's years since I was hands-on, but from memory the best had a blade welded across the tip. There is no chance of them popping off later. For 40mm you need a few screws, or to predrill with a quality bit.