Plumbing, Plastic Pipes and Limecrete

[CarolineTheChemist]

Hello PPers!

I need some advice from you all about plumbing and limecrete floors. We’re soon to replace our entire ground floor with limecrete and are planning on adding some plumbing for the radiators. Underfloor heating is a no-go for us as we want to have a nice thick carpet. Our plumber is concerned about putting pipes in the floor as he’s never worked with limecrete before. He says he’s been told it’s an acid (he’s clearly not a chemist) and it will corrode absolutely everything - including plastic trunking. I pointed out that limecrete is often used with wet underfloor heating, so it can’t be that corrosive. We also called our local lime yard and they said plastic pipes would be fine, but perhaps aluminium would be a bad idea.

What experience do you all have with putting pipe work in/on limecrete? Any things to avoid?

Thanks everyone!!

 

[a twig]

Plastics are fine in lime - metals vary:

https://www.researchgate.net/public...M_CORROSION_RESPONSE_OF_METALS_IN_LIME_MORTAR

Just in case someone is searching in future and doesn’t see the other thread

 

[paulc]

Our plumber is concerned about putting pipes in the floor as he’s never worked with limecrete before. He says he’s been told it’s an acid (he’s clearly not a chemist) and it will corrode absolutely everything - including plastic trunking. I pointed out that limecrete is often used with wet underfloor heating, so it can’t be that corrosive. We also called our local lime yard and they said plastic pipes would be fine, but perhaps aluminium would be a bad idea.

Lime is an alkali, and most plastics are resistant to its effects. Copper will eventually corrode, so is best protected by a layer of plastic. 20mm round conduit is just the right size to sleeve 15mm copper pipe. If you are going to be burying pipe in a solid floor, make sure there are no joins that could potentially leak - That applies regardless of which material you use (copper or plastic).

 

[Cubist]

One of my golden rules, inherited from my father - never, ever, ever bury service pipes in walls or floors if you can possibly avoid it. If it must be done ensure that all metal pipes are shrouded in plastic where they contact any coating material - and always be prepared to rip out the wall or floor in which the pipes were buried when they ultimately begin to leak.

 

[CarolineTheChemist]

Thanks everyone!

I don’t think he intends to bury the pipes directly in the floor - he was intending to use some kind of plastic ducting that houses the pipes, but is covered with a lid so we can access it by lifting the carpet and then the lid.

A bit like this stuff…

Anyone used something like this before?

 

[Cubist]

Left to me every house would include a services channel network linked via a vertical spine across all floors. Takes a lot of the expense and pain out of future diagnostic, repair and modernisation works.

 

[Roger440]

Left to me every house would include a services channel network linked via a vertical spine across all floors. Takes a lot of the expense and pain out of future diagnostic, repair and modernisation works.

Thats sensible. Will never catch on.

As someone from a maintenance background, iver never understood the building trades approach to these things.

If i was building a house from scratch id be doing exactly as you suggest.