Putting pipework in limecrete floor?

[that bloke.]

To make life easier i might try and put all the ground floor central heating pipes in the floor, we plan to put in limecrete floors as we have to lift the cement floors anyway to remove the DPM and take control of the damp/moisture levels in the walls (long story) by putting in a breathable lime floor instead, anyhow, can any of you guys see any problems with this? its a good few long runs of pipework, mostly all the pipe work in fact. Id be using soldered copper in a decent insulation sleeve but is there anything i should be aware of? do i need to leave room for expansion for example?
Ive ran pipes under floors before but not this amount of pipework.

 

[justlead1]

Expansion is always an issue along with corrosion potential if moisture become present. Make sure say a foam lagging is used at changes of direction and where tee pieces are used, this will allow movement without stressing the pipe and joints. You could also bend a couple of expansion loops to reduce movement of 10 m run. Good Luck

 

[metaldust9]

id sleeve the pipe or wrapped the pipe in a tape like denso or buy insulated copper pipe ,it not cheap but cheaper than having to rip your floor up as the lime will attack the pipe

 

[that bloke.]

Cheers guys, the main problem i can see is like you say the lime will attack the copper, another issue is the limecrete floor is designed to allow moisture to pass through it, this might collect around the pipes in the form of condensation, is there any kind of water proof insulation i can use?

 

[Billy Bob Bob]

i would avoid putting copper in the floor for the reasons stated,what about plastic? copper where its in sight

 

[ecowarm]

as far as i know copper is not attack by lime, i have worked in lots of old houses with unlagged, unprotected copper pipes burried in the wall and no damage ever by lime.
Different with cement though

Eco

 

[stevetheplumber]

you can buy plasic already sleved or sleved and insulated not cheap but labour cost of laying are lower

 

[that bloke.]

I did consider plastic guys but what about putting push fit T's embedded in the floor? I dont know if i could trust them enough, I am pretty sure they would be ok and pass a pressure test but I think i'd still prefer copper for piece of mind , mind you I havent priced any of this up yet.
If i do use copper I take it a bent expansion loop rather than 4 elbows would be best?
Cheers Eco , thats good to know.

 

[WHPES]

Denso tape if you are using copper pipe.

 

[ecowarm]

yes a bend is always better than elbows, I would use foam lagging or if not enough room felt lagging.

Eco

 

[Gray0689]

Youdont need expansion loops in 10m runs if your using foam lagging 15mmx9mm 22mmx9mm
28mmx9mm

 

[Reg Man]

Careful of Denso, it can absorb lime. If you use Denso wrap polythene around the outside as well, it helps to hold the Denso webbing compound in and stops it drying out, also makes a membrane barrier against anything corrosive. Certainly the cheaper option.

 

[Reg Man]

Lime is not a big problem for copper, Sulfur, and quick drying cement and the likes are a bigger problem.