making good over chased in bathroom pipes?

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Just wondering about correct procedure when making good chased in bathroom hot and cold copper pipes and plastic waste pipes. Is a coat of bonding, skrim joints and a two coat skim sufficient? Ty liam.
 
They need to be capped, ideally behind plasterboard, so that the pipes can expand and contract behind. If they're in the wet plaster they'll crack then shrug the plaster out.
 
I'll invest in some of this denzo tape as everyone seems to mention it but the jobs tomorrow and I haven't got a chance to get any. Have I any other options for best results. I'll be skimming over the chases..
 
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hi Liam,sorry for the stupid answers so far,use denzo tape over the pipes ,fill the chase with whatever material is on the wall and skim it or easi fill it then

Copper pipe has a linear expansion coefficient of 0.017 mm per metre/per degree. So a short run of say two metres with water at forty degrees temp rise will give you 1.5mm. So every time the hot water pipe has flow through it, and every time it stops and cools it will expand and contract. That doesn't allow for the radius of any covered bends opening and closing, nor does it take account of the pipe being clipped before or after the run through the wall, both of which will increase the movement.

I'm not a plasterer though, so I don't know what skims like for it's ability to flex and stretch. I'll take a guess though and say it doesn't.

So there are stupid answers, but not the ones recommending allowing the pipes to move without being embedded in plaster. :RpS_lol:
 
Copper pipe has a linear expansion coefficient of 0.017 mm per metre/per degree. So a short run of say two metres with water at forty degrees temp rise will give you 1.5mm. So every time the hot water pipe has flow through it, and every time it stops and cools it will expand and contract. That doesn't allow for the radius of any covered bends opening and closing, nor does it take account of the pipe being clipped before or after the run through the wall, both of which will increase the movement.

I'm not a plasterer though, so I don't know what skims like for it's ability to flex and stretch. I'll take a guess though and say it doesn't.

So there are stupid answers, but not the ones recommending allowing the pipes to move without being embedded in plaster. :RpS_lol:
And what's den so tape for ? It's been done for decades under floors and in walls, theories all you like but your answer is stupid like mine too
 
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If you have the depth use, foam lagging, you can get it anywhere. It will allow for expansion and protects also, but otherwise use denso or at least duct tape for erosion
 
Just wondering about correct procedure when making good chased in bathroom hot and cold copper pipes and plastic waste pipes. Is a coat of bonding, skrim joints and a two coat skim sufficient? Ty liam.

The correct procedure would involve burying the pipes deeper to begin with, not expecting a couple of mm of skim to solve a lazy ar$ed plumbers' problems :RpS_thumbup:
 
Plastic pipes would have been friendlier here.

Is there enough depth to chop out either side of the pipes and nail/fix EML, spanning a few inches?
 
The copper pipes need the denzo over them to protect them from the gypsum or they will eventually corrode too.
 
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