saveasteading

It's not for us to say. It is a project specific thing, so your SE should advise on the structure, not the BCO. The BC can advise on insulation and damp, not that they should be designing for you. But as an overview, and as @Russell griffiths .. that is a big beam with a big load and the footing is absolutely NOT designed to support it.

Site survey completed. Concerning timber only. The results are in. The Architect and Engineer work in metric. The workers talk in imperial as in "fetch me a 6 x 2 about 6 ft long. But they measure in mm. When talking designer to chippy, it is 6 x2 etc for ease of discussion, but lengths are in m. The younger designer never learnt imperial but has learnt to accept this parlance as "the way it is". Builders' merchants accept an order for 6 x 2 but confirm and invoice it in metric. And on education. For my childrens' (1990s) education they were taught cm, not mm. Real life has changed this and current teaching at primary includes both cm and mm but still no imperial.

The only time I use imperial is in chat with someone aged over 45. Then you might describe a timber in inches. Eg 6 x 2 It's actually much more practical than describing it as 150 x 50, or 15 x 5. Or 147 x 47 etc. Or nails being 3 inches. But it would still be a length in metres in ordering and in cutting. It would be a very bad idea to design and work in imperial. Steel beam dimensions are actually usually still in the historic round numbers in inches but are now always calculated and bought in mm.

A general point re rainwater capacity. The rainfall diagram above is becoming out of date, as some areas of the country are getting exceptional downpours. The annual rainfall is irrelevant, but what happens over 15 minutes can cause problems to your system, or over days to the whole area of infrastructure and waterways. So it is best to future-proof by overdesigning OR having somewhere else for the water to go. So what if: What if a downpipe is blocked? does it escape safely over the gutter or go backwards and cause issues? Using 2 x dp set well apart or having a weir overflow prevents this. What if your drain doesn't quite cope with the flow, or another drain downline is over capacity? An open gully as above allows the water to run onto the ground, but make sure that can run away from the building.

Compriband is a trade name but in a search brings up lots of copycat or simply squishy foam products. I didn't realise Compriband, capital C, could breathe so there must be more products than I know of. Why does it need to breathe if it is non absorbent?

Compriband is difficult to compress. It is used to seal bridges and dams, and does not go squishy. It sounds as if you have diy draughtstrip.

If you provide compriband expanding strip, or an equivalent, then they might fit it. They're clearly not intending to. I think that's the only best method.

Agreed. It's better to have a good job with medium insulation properties than gaps in a better insulator. You could perhaps maintain the 25mm air gap by first inserting a board to the roof slope, then removing it. Rockwool type material should be the waterproof variety in case there is ever a leak, as soggy wool would be a bit problem.

Was it not always so?

Just ask how they are dealing with sealing.

As long as the pipe is fully home. I've seen miscuts used that should have been done again. The risk is when the plummeting solids hit the bend at the bottom, forcing it downwards. But if that is properly bedded, again no issue. It's good to understand the products and to seek reassurance where necessary.

No. Just think of the effect downstream and the answer is clear.

let's see your sketch please, when done.

this will be noted during any search process, so the vendor should be advised to allow for this reduction. unless of course they think it is allowed already in the asking price. MY inclination would be to do less rather than more, ie clean it out and increase the soakaway. £2-3k ? But at worst case you do this and it `works for a while then ceases to work, so you end up with a treatment tank. £12k. £5k allowance reasonable, depending on how much diy is involved and any design costs. Others may say allow more.

Most? Certainly a lot: a relative had their semi assessed by some unskilled operative, I think sent by the electric company for no good reason. All he noted was the original construction and ignored the huge improvements. And I know the developers used to tart one unit for testing, which is fraud basically. Do they still? But even a poor assessment is a start and the heating cost should be noted in the value.