siting an unvented cylinder on sloping floors

[Jay The Plumber]

evening folks, im putting an unvented in an old farmhouse in an upstairs room alcove area that will be eventually made into a cupboard.
being an old farmhouse, the floor is all over the place, I put a bit of fibreboard down and levelled it but the floor is out in a compound angle and is a real dog to get the cylinder dead plumb..
anyone got any top tips or use some tricky levelling feet etc that you could recommend?

 

[ShaunCorbs]

unistrut with a 18mm board of ply and m12 backplate (with a 12-18mm ply on the floor first)

but how out of level is the floor ?

 

[Jay The Plumber]

It's about 20 mm out in total diagonally sloping up to the high point in both axis.

 

[ShaunCorbs]

It's about 20 mm out in total diagonally sloping up to the high point in both axis.

could you screw some 18mm ply on the low points and put a sheet across the lot and screw down?

 

[Chuck]

Don't forget to check the floor is constructed in a way that can support the load. If it's that out of level...

 

[Jay The Plumber]

Don't forget to check the floor is constructed in a way that can support the load. If it's that out of level...

I understand the sentiment of the question, how should we do this as installers? are we competent structural engineers?
should we make the customer pay for a structural engineer to check?

its an upper floor of fossilised farmhouse joists and boards...

 

[king of pipes]

4x2 Cls timber and 18mm ply to make up a base, get yoursef some plastic packers to raise the timber to the angle of the slope then a skill saw to rip it down if its upper floor make sure its sitting over a supporting wall to take the weight of the cylinder once its full regards kop

 

[snowhead]

how should we do this as installers? are we competent structural engineers?
should we make the customer pay for a structural engineer to check?

It may sometimes be necessary.

Sometimes old floors can be rotten wood held together with a lot of sand and cement that wouldn't pass and building control inspection today.