Mr Punter

I understood that the OSB vapour openness can vary significantly by brand / batch, so I would polythene over this. Quick to do with a stapler. Run it down to the floor and trap it with the skirting. Where are electrics going to be?

If you have lots of these still to drill it is worth making up a template from ply or mdf and clamping it to the door. Forgive yourself. We have all done far worse.

I have seen some OK extra floor conversions on bungalows, but if the current layout needs much modification it is better to start afresh.

You may find that your household insurance policy gives some legal cover. These are normally no win, no fee, so if they feel you have a less than 50% chance of success you are on your own, but at least you may get a considered legal opinion FOC.

You can get auger bits that claim to be nail proof

Have you looked at stainless hooks? Zero uplift on windy days.

It is really not great, but I have seen worse. A shame you did not carry out the work or supervise as I am sure it would have been a much better job. Getting this resolved is a PITA but when all is said and done, nobody died or was injured, so it will just come down to money. For a total project of £30k, legal and professional fees can quickly dwarf this, so think realistically what would be an acceptable compromise and get the other side to do the same. Often when these things go to court, both parties can lose out over what they think is fair and only the lawyers are happy.

Unless the pool is worthwhile for you, you could have it filled in. An outdoor pool in England can sometimes be a white elephant.

I have had big 5 leaf bifolds 5m. and when opened back they tended to slump. I have also had 3 leaf 3m. and they were better. Lift and slide would be my preference now. More controllable and airtight.

+1 I changed a couple of door handings and although drawings were updated, the electricians worked from an old set of drawings we had sent out for quote purposes, so there was some messing to get light switches in the right place.

So have you just parted ways, calling it quits, or is one of you wanting some money from the other?

Is it now the case that the roof is correctly membraned by others, Velux properly fitted and you are waiting on the Velux flashings to complete the roof?

You can see why mould likes these cold corners!

Are the pics you took with your under cupboard lights? Can you do a photo in normal daylight?

You can strain a bollock if you lift it on your own.