Central heating pipes in cavity wall

[wheeto]

Hello,

Are there any regs relating to installing new heating pipes in a cavity wall? It's an external wall and was retro-insulated about five years ago.

I can see the obvious disadvantages to this, just wondered if there were any concrete rules?

Thanks,

 

[SimonJohns]

Shouldn't have anything in a cavity

Chase the wall out or trunking. Much safer if you get a leak and easier to repair

 

[Henchman76]

Yes thats sound advice and one to be heeded. Imagine if you sealed your pipework in place, decorated nicely and then 12 moths down the line you started to observe a saturated carpet ! One big whooping headache

 

[wheeto]

Shouldn't have anything in a cavity

Chase the wall out or trunking. Much safer if you get a leak and easier to repair

Thanks. Someone's seen his spark fish cable through the cavity and wonders why he can't do the same with his heating pipe. And I'm struggling to come up with a really good reason why he shouldn't with, say, plastic-coated copper.

Surface-mounted pipes aren't really an option because the rad needs to be in the middle of an enormous wall, and chases would need to go all the way up the wall to drop to the radiator so would be really messy.

Leaks in the cavity don't really worry me - there wouldn't be any joints, and it's a sealed system so would drop (say) 5L if the worst came to the worst. Still don't like the idea! Any solid objections though?

Closest I can get is energy efficiency, as it would be impossible to fish lagged tubes through the cavity. Having said that the space is insulated so you could argue that being surrounded by cavity wall insulation counts as insulating the pipe. Argh.

 

[Henchman76]

Personally I wouldnt lay pipes in a cavity but thats me. My mind would be on having knock through the wall to trace and repair said possible leak. I would always use slimline capping or recess them into wall, yes its a messy affair but you KNOW exactly where they are and gaining access to them would be alot easier.

 

[AWheating]

you will have an increased risk of dampness, corrosion etc.... anything that touches the outside wall and then the inside wall can carry mositure into the internal wall, this is one reason cables are not supposed to be installed in cavitys. you will also have the chance of the pipework freezing and splitting.