Prevention of damage to UFH pipes when pouring and finishing reinforced raft

[Smallholdertoo]

We are due to pour our insulated reinforced raft next Friday. It is all ready except for

1)  sealing and tying down a block of XPS attached to the  waste pipe to give a void for the shower waste.

  -  Do I need to cover in DPM?,

  -  PU foam around the pipe to seal concrete out

  -  Is tying down the XPS with wire OK.

  -  Should I lift it up from the rebar mesh using concrete "mars bars" to help continuity of concrete and

2)  How to protect the pipes under the manifold from over energetic power float operators! Possibly boxing out the area with plywood?

 

Any suggestions on the above or the pour generally would be gratefully received.

 

 

[MikeSharp01]

Fill and pressurise, but don't over do it, the UFH pipework to prevent it being crushed maybe. 

[Jenki]

28 minutes ago, MikeSharp01 said:

Fill and pressurise, but don't over do it, the UFH pipework to prevent it being crushed maybe. 

having a pressure gauge to check is a nice reassurance, I filled mine with air to 1 bar, be prepared for this to rise when the concrete heats the air :).

looks like yours is pressurised already?

The pipe is tough and as long as you keep excited labourers with sharp shovels away  you should be fine.

Secure the XPS or it will want to float away. any tape that will stick to the XPS will be ok to seal the pipe.

Personally not keen on zip ties to secure the pipe (as these can snap with a bit  too much eager poker vibration) especially the small black ties. 

The two black ducts try to get vertical possibly tie to the manifold board, it would do my head in once finished and the pipe come out of the floor at an angle.

 

Cover the manifold otherwise it will get splashed with concrete from vibration.

1 hour ago, Smallholdertoo said:

How to protect the pipes under the manifold from over energetic power float operators! Possibly boxing out the area with plywood?

 

I used offcuts of insulation, its was easier to get out afterwards.

59 minutes ago, Smallholdertoo said:

  Should I lift it up from the rebar mesh using concrete "mars bars" to help continuity of concrete and

IMHO wouldn't hurt either way.

[Smallholdertoo]

47 minutes ago, Jenki said:

having a pressure gauge to check is a nice reassurance, I filled mine with air to 1 bar, be prepared for this to rise when the concrete heats the air :).

looks like yours is pressurised already?

The pipe is tough and as long as you keep excited labourers with sharp shovels away  you should be fine.

Secure the XPS or it will want to float away. any tape that will stick to the XPS will be ok to seal the pipe.

Personally not keen on zip ties to secure the pipe (as these can snap with a bit  too much eager poker vibration) especially the small black ties. 

The two black ducts try to get vertical possibly tie to the manifold board, it would do my head in once finished and the pipe come out of the floor at an angle.

 

Cover the manifold otherwise it will get splashed with concrete from vibration.

I used offcuts of insulation, its was easier to get out afterwards.

IMHO wouldn't hurt either way.

Many thanks for your comments - yes it is pressurised and has not dropped since yesterday (no sun either day).

 

Lots of good points to apply

[JohnMo]

3 hours ago, Smallholdertoo said:

protect the pipes under the manifold from over energetic power float

I would get some insulation offcuts and box the pipes in to bottom of the wooden backing board, do a few layers of insulation if you need, foam it all together, but not the pipes. Let them do the power floating, then removed the insulation and fill the void with self levelling compound flush to floor.

[Nick Laslett]

Looks great. Continental, good UFH gear. Good luck with the pour. 
 

I went round snipping all the zip tie tails. Just can’t bare that sort of thing. 

[Spinny]

How will they pour the concrete in ? pumped through a pipe ?

How will they move across the slab area ? Walk over it ? Using boards ?

Pic of my 'power float'

[Spinny]

9 minutes ago, Nick Laslett said:

I went round snipping all the zip tie tails. Just can’t bare that sort of thing. 

So did I as the plumber didn't bother and they were long. Missed a couple and can see the tips in the surface of the slab now.

[Spinny]

If being pumped in then be aware the first stuff out of the pipe can be very very watery and in an ideal world you would dump it outside the area.

Don't get it on your hands or skin, do wash it off absolutely immediately, I can testify it burns.

One of our young labourers turned up in shorts, had to run around with buckets of water to wash it off his leg.

 

Good luck.

 

Don't worry too much about the pipe, ours got abused but survived.

Edited Saturday at 15:43 by Spinny

[Smallholdertoo]

4 hours ago, JohnMo said:

I would get some insulation offcuts and box the pipes in to bottom of the wooden backing board, do a few layers of insulation if you need, foam it all together, but not the pipes. Let them do the power floating, then removed the insulation and fill the void with self levelling compound flush to floor.

I will good idea

 

3 hours ago, Nick Laslett said:

I went round snipping all the zip tie tails. Just can’t bare that sort of thing. 

I have started - it will be done by Friday

[Smallholdertoo]

Knee pads found - all zip tie tails docked.