stu w

I would say no. 30kw required

Wavin Osma or polypipe hands down. Brett martin, hunter etc are cheaper alternatives, but as everything cheaper for a reason

I have just gone through a similar scenario with ST water. As nickfromwales has said. Follow their guidelines, 750mm deep , sand both sides depending on the ground etc. I used barrier pipe just because I was unsure of the ground , yes it's more expensive but once it's done it's done . They were happy with a series of clear pictures of the installation. Brass stop tap on the inside and proof of insulated ducting where it come into the house

A PRV may help depending on your current water pressure. A shock arrestor will help also on the fees whats causing the problem. Listening to you recording, It sounds like there is a pipe what hasn't been clipped back properly somewhere

Agree , I have worked on several of their builds but never been to their factory , hence the visit to see where it is all made. It was nice to see things from both sides. The visit was very informative and professional until the final section, which was the window and door presentation, this was horrendous and very uncomfortable the way it was presented.

Have a look at MBC, I did a tour of their factory recently and they have a good well made product.

I usually use cls , dry, straight and readily available

What section of timber are you looking for ? . Modern treated timbers are far safer than the old CCA treated timbers.

Painting it will be fine if just standard emulsion I have never had an issue with tiling onto painted walls in a kitchen. Also if you ever decide to change the tiles in the future, there is less chance you will destroy the walls taking the tiles off

Request them to remove them and use them as cuts if possible. They're shouldn't be blocks with large sections missing they should be whole and in good condition

Don't rule out rockwool nyrock frame slab, I have used it several times now and an excellent product

I have installed a large amount, they are both very good . My personal opinion is I prefer Hardie especially the VL plank

If in doubt especially for a sole plate, I would use pressure treated timber

Difficult to tell from that picture, could just be discoloured from age or the sun, but could also be vac vac treated. I would say it's not pressure treated personally . Trim a tiny bit off the end and see if there is impregnation marks

As said D4 Spax wirox flooring screw