Push fit or solvent weld soil under concrete?

[SHBS]

I am about to install the drains for a mill conversion and as they will run under the concrete floor I would like to use solvent weld fittings for a more permanent job. However, I can only find a push fit rest bend for the bottom of the stack. This makes me think that solvent weld is usually only used above ground and push fit underground. Is that the case?
Stuart

 

[AWheating]

yes, push fit orange plastic is the standard for under ground soil/drainage pipework. make sure you use filed edges and plenty of grease, support the pipework correctly and you will be fine.

 

[stevetheplumber]

yes it push fit for underground should be laid in pea shingle if its a concrete floor you may need to put mesh over it as well

 

[SHBS]

Thanks for the quick response gents. A bit of mesh is not a bad idea although there will be pea gravel, 100mm of sub-base, 100mm of concrete, 200mm of insulation and 75mm screed over it so I think it should be pretty safe. You wouldn't be tempted to use solvent weld then?

 

[Gray0689]

Thanks for the quick response gents. A bit of mesh is not a bad idea although there will be pea gravel, 100mm of sub-base, 100mm of concrete, 200mm of insulation and 75mm screed over it so I think it should be pretty safe. You wouldn't be tempted to use solvent weld then?

NO push fit is the way it's ment to be one with corect underground drainage pipe your building control officer will want to see it before it's covered over also

 

[dontknowitall]

Push fit can expand and contract a little and still maintain it's join whereas solvent weld could crack under the same circumstances.

 

[Guest123]

As stated above, pushfit allows for thermal movement and will remain intact. I had a drain fail its test recently as I used a couple of cheaper branded fittings on a part of the run and when changed the drain test stood ok. I now don't mix different brands of pipe and fittings on drains although they should all be 100% compatable with each other.

 

[SHBS]

Thanks for all the excellent advice. I am now much happier about my drains but how about above ground? Push fit or solvent weld?
Stuart

 

[Guest123]

Both pushfit and solvent weld have their uses. I prefer pushfit as it can be dismantled where sovent weld can't. However for this reason, solvent weld is a more secure option in innacessable areas. Purely a matter of personal preference and I carry stock of both and in the case of waste pipe I also use Multifit as it's the best way to adapt on old existing systems, then I can use pushfit or solvent weld after that.
I think that pushfit has the slight advantage of being able to be used immediately, while solvent weld needs time for the glue to set properly before use.

 

[dontknowitall]

I prefer push fit for 110mm (easier to install) and solvent weld for the rest (looks much neater and more professional).

 

[AWheating]

agree with the above.