Boxing in pipework and cabling on breathable walls

[overlander matt]

I need to run pipework and cables on the inside of an external wall of the house and then cover it over with an appropriate board and lime plaster. I'm wondering what the right approach is to prevent any damp. If breathability were not an important factor I would attach plasterboard to 2" timbers screwed to the wall... Any suggestions would be greatly appreciated.

Thanks.

Matt

 

[Abi Cott]

Horizontal or vertical?

 

[Easrow]

Much of ours is behind a plasterboard in the kitchen. We used roofing batten on the wall running vertical at 400mm centres. Then used foil backed 12mm plasterboard but lifted off the ground so there is possible ventilation as the top went up in the ceiling void. Our other thought is that the wall should be able to breath to the outside at least. We have flagstone floors laid onto the earth as well. No issues yet. It's actually drier in there since the room was done. Might not be correct but worked OK for us.

 

[Feltwell]

Are we talking the whole wall here Matt, or just a small part of it? I wonder if you're worrying too much....

However, I've got a couple of breathable options for you. First off, a breathable board of some type, skimmed over with lime plaster - here's Ty Mawr's board guide, several options:-

https://drive.google.com/file/d/1nwm3QpQHnW1agbbWJ0Ji6Ne3-lRQr8WM/view

Secondly, the forerunner of all plasterboard, lath & plaster. Nail laths across battens and plaster over, pressing in a haired base coat well so it squeezes in between the laths and forms nibs that hold it all on, before skimming with a finishing plaster. Guaranteed to be breathable!

Is there any damp in the wall? I'd be tempted to use treated timber for whatever you screw to the wall, can't hurt.

 

[overlander matt]

Thanks for the replies. I'm not really sure I want to get involved in any lath and plaster work on this occasion Feltwell. The wall is in a stairwell running between the ground and second floor although I won't line the area below the half landing on the ground to first floor stairs (which would be the area most susceptible to any damp). It's a narrow strip 400mm wide either side of a tall window as you can see in the photo below. There was previously some timber boxing on one side and some deep chasing on the other side to accommodate all manner of different pipework and cables. I don't think I will have problems with damp on this wall but it s difficult to say with certainty! I have let this wall get a bit wet following repairs to the roof when there was no rainwater downpipe fitted and there are a few damp patches inside that I would expect to dry up in time. The artex and gypsum plaster will be removed from this wall before it is boxed in.

Is a moisture resistant plasterboard a sensible choice in this case?

Thanks in advance,

Matt

 

[Feltwell]

If it's not obviously wet then MR plasterboard should cope fine, but I'd be tempted to at least try and get some ventilation access top & bottom if you're not going down the breathable route. I've seen some horrors being wainscotting that wasn't ventilated!

At some point I'll get rid of the mdf faux tongue and groove that a previous owner gripfilled over the knackered wall tiles in my downstairs loo.... :roll: