Hot water cylinders on platforms

[goaty_man]

Guys,

Are you able to tell me if it is now a compulsory regulation to install a hot water cylinder on a platform (even if it is just two small pieces of wood). A plumber told me that this was the case and as a result my pipework would have to be modified (meaning more expense).

If this is the case I'm happy to pay for the job to be done right, if not am I ok to have it standing on my floorboards? If it makes much difference one of these boards can be lifted without problem to gain access under the cylinder anyway.

Many thanks

Goaty

 

[Bahco]

The reason cylinders are placed across 2 3x2 joists are to ventilate the underside of the cylinder.
Water would condense there due to the inside temp being hotter than the outside of the cylinder so it would be imprudent not to do so.
I would say your cylinder would rot a lot quicker underneath if you do not allow for ventilation.

 

[oilman]

I don't know of such a regulation, BUT, I would want at least one joist under the tank and preferably near the middle so there is some support. If you have widely spaced joists the tank may be between joists, and if the boards are chipboard this is not good.

If you need support, take the tank out, remove the floor boards, and add a support under the boards connected to the existing joists, then put back the floorboards and the tank.

 

[Bahco]

I didn't read your post correctly and it seems to me you have the cylinder in the loft
My advice (aside from the correct load support from Oilman) is unchanged.
Make sure the cylinder and cistern are properly supported weightwise and ventilate ensuring air passes underneath the cylinder

 

[PEDANTICVINDICTIVEMAN]

Yea that rings a bell from years ago about ventilating under cylinders, thing is we never needed to with the old ones, it's only since cylinders were made from paper thin craap that it came in.

 

[ChrisR]

What's this about copper needing ventilation? Sounds like hogwash to me. I'd put a cylinder on ordinary floorboards. Loft floors are a different matter, from the strength aspect.

 

[PTH]

Bahco - why would there be condensation on a hot surface?
For chilled water vessels it's a different matter!
The main reasons for putting timbers below a cylinder are to spread the load over at least two floor joists and to give a bit more room for using the drain cock or getting a spanner on your lower coil connections!

 

[Bahco]

We were taught at college that the underside of a cylinder must be ventilated hence placing it on top of 2 joists. Not up on physics but makes sense to me that condensation will collect on the cylinder underside if there is no air ventilation

 

[PEDANTICVINDICTIVEMAN]

So what happened to all this condensation on the old cylinders, it's all boilocks, sounds like some suit and tie trying to justify his job (AGAIN), rhymes with clucking bell.

 

[ChrisR]

Yes. And I'm a comparable weight to a 36x18. If I stand on the ball of one foot, the lucky floorboard really doesn't seem to bend much at all...

 

[bripl]

i do believe the nhbc insist on battens under the cly for ventilation/prevention of condensation on the ass of the cly to prevent rotting of the chip board floor. concrete floors battens are used to stop rapid heatloss as the cly ass is uninsulated just where they sit on the floor,apart from that it would be considered good practice to have some batons placed under it.