Filling holes left by plumbers PICS

[Albopalbo]

Plumbers installed a new radiator and chased the pipe into the floor. How do I now fill it? Is there any specific prep work I need to do first? Any special sort of concrete to use? Ta.

 

[joinerjohn]

A plumber seriously did that job?? Never in a million years. Even a CCC couldn't get it that bad.
You can't just concrete over bare copper pipes, they will react with the concrete and in a few years time they'll leak like a seive.

 

[Albopalbo]

The pipes were already there under the floor. He also said it's not ideal to sink them into the floor and wrapped the pipes in something to help protect them.

 

[mac391]

Remove most of the loose material and fill with a dry mix (very little water) of 3 gravel (10m) 2 sand, 1 cement.

 

[Albopalbo]

Thanks. I have had a few different answers to this query and I have no idea which is right.

1. Dry mix of gravel sand cement
2. Fill with leveling compund
3. SBR slurry mix
4. SBR slurry then screed over top while still wet
5. 4:1 mix poured in after wetting the sides.

which is right!?

 

[mac391]

All of them are right really. Your existing structure is concrete. i.e sand, gravel, cement. But the whole you are filling is very shallow so either a 4/5 to 1 mix of of sand & cement or 3 gravel, 2 sand, 1 cement. The gravel (10mm) just adds extra strength but not absolutely necessarry. Even if you mix it too wet, it's fine just pour it in and level off.