Mr Punter

I don't think it is acceptable. Get the contractor to take it up with their supplier. They should all be from the same batch.

+1. They are being idiots. Foundations are commencement. You don't need a LDC. Just carry on.

No I made sure the ends landed on a joist.

Not if they did not implement it. You can have many consents and choose which you prefer.

You will probably need consent from the local council to make this into a driveway. You may also need to have the kerb dropped at the road edge of the footpath and the path resurfaced, all by an approved / fully insured contractor. Try harder to lift the chamber lid. A couple of long lifting keys will help.

Yes, you can build within 6m of a large tree. You will need a solution that is engineered to accommodate soil heave / shrinkage and not cause damage to the tree or the foundation. May be easier to fell the tree.

No I just glued the T&G joints. I am not too concerned as there is a heavy overlay board going on top, as well as some stud partitions.

I used some 18mm T&G OSB for a temporary floor and fixed it with 1 screw per board. No issues at all. I have since fitted new 18mm T&G OSB, glued at the joins and with loads of screws and nails. Quite a bit of squeaking / creaking.

You could argue that it was part of the original planning. There is no time limit on planning once the development has commenced. The approved plans show a timber fence, I assume 1.8m high (could not see in the plan you posted). Tell them you have built in accordance with the stamped approved plan.

If you have an excavated trench, either concrete it to form footings or backfill it. Don't leave it open.

You may do well asking Building Control and your warranty provider if they are suitable. Often these are more for pylons, conservatories etc.

If this stuff is that sensitive to a bit of rain it should be indoors or in an enclosure.

Proper old school plan! I am surprised they used millimetres!

I think this looks fine. I would be happy if my plumbers worked to that standard. What do you think is the actual issue?

I have been using the Atlas concrete screws and they seem good and less than half the price of screwfix: https://www.dryvergeandrooflinedirect.co.uk/products/atlas-zyp-concrete-screws?variant=40578226651326

That will be very very expensive. Think 6x the price of blockwork.

I am not keen on tape and fill. It doesn't seem to give such an even finish when painted. That said, it is what they have in almost all commercial areas you see. I hate the dust from tape and fill and the mess from plastering, so take your pick.

I think you are better rodding in the direction of flow. If the pipe gets blocked, where will the rods push the blockage? Can you get an access where it exits the wall?

You can do the studwork before or after screed.

You can easily have a modern twist on a design without it being a pastiche. Go with what you want. It is your land and money.

Hi Tony and welcome. At 75 you are not as aged as some of the old gits on here!

It is really difficult to design yourself. Much easier to work from drawings. £100 is very little but if you can get this deducted, all the better.

+1 If you had a structural warranty you may have been in with a shout up to 8 or 10 years.

I would hook out the trees before any talks with the planners. Detached house looks quite plausible.

The water reducing additives - superplasticisers - allow the concrete to flow easily without addition of excessive water, keeping the concrete strength high and the water content low. If you use this in formwork and there are any "issues", it pisses out pretty fast. I wouldn't bother on a slab if the concrete crew are good.