Aah... didn't realise that it might advance the BSC. Thanks LadyG.
Basically, it's a newly-acquired narrowboat that has previously been used for leisure purposes. I know there's a problem with perishing rubber hoses out of the gas locker, want to remove the existing oven & hob, and replace with LPG hob/grill and (probably) Bubble multi-fuel stove with oven pod. I need an engineer quickly to resolve the immediate safety issue and disconnections but also want advice on the installation of the stove/oven. I've used the sheet (thanks Jen) extensively, coupled with instructions from the Bubble manufacturer. My question - which even Harworth Engineering can't clearly answer - is that there is a requirement for the tile/air-gap/calcium silicate board sandwich appears to be required to extend 200mm above the top of the stove. Now, a Bubble with oven is 820mm tall and sits on a plinth/hearth and is, say, 80mm from the sandwich under the gunwale. What I want advice on is what happens with a wood-panelled tumblehome? can I clad the tumblehome and underside of the gunwale with silicate board (which will involve exposed joints) or do I have to move the whole stove installation toward the centre of the cabin so that I have a single vertical sandwich that is about 1.1 metres high?
Jen, you're observation that HETAS engineers also serve houses equally applies to Gas Safe engineers. That's why I made the appeal on this forum - in the hope I can find someone you undertands BSS regs and can advise on both aspects.