Plastic waste pipe behind oven

[littlepigeon]

I'm in the process of fitting a kitchen and cant get away from the washing machine waste needing to run behind a free standing 90cm range cooker.

I've been told to use no less than 38mm pipe which ends up being 40mm as that's all that is available.

Is there anything that can be done to protect the pipe from heat? Do I need to? Will this be a problem? Is there a particular type if pipe i should use for the run behind the oven?

Any helpful tips greatly appreciated

Cheers

 

[Madrab]

Round 2 in your re-routing pipe LP

It all depends on how hot the rear of the range gets and how close the pipe is going to be when installed?
If the range gets too hot to touch and the pipe is going to be right up against it then you could have problems
Wrapping it in heat reflecting tape may help but never had to test it in that kind of scenario.

 

[littlepigeon]

Round 2 in your re-routing pipe LP

It all depends on how hot the rear of the range gets and how close the pipe is going to be when installed?
If the range gets too hot to touch and the pipe is going to be right up against it then you could have problems
Wrapping it in heat reflecting tape may help but never had to test it in that kind of scenario.

Yup! Im sure there will be a round 3 4 and 5 probably! I think it will win though. The only other option i could have is maybe running through the 9 inch wall and run it on the other side of the wall then back into the kitchen at the other side of the room, then out through the kitchen to the drain. Unfortunately i cant go outside from the other side of the wall as i would just be going out through a door of the out building as its only a thin old outside toilet.

Drilling through 9 inch walls is something i don't have the tools for though

 

[denso13]

Will the cooker actually be in contact with the pipe?

 

[newbuildinstaller]

push fit pipe is high temp (suitable for boiling water ie TPRV termination) surely the back of the oven cant get past that or it would become a fire risk??

 

[nickjb]

How about using 42mm copper? A 3m length will be around £35 so it won't be especially cheap but it might be cheaper than other options. You could couple it into plastic waste with a flexi coupling or it might fit a 40mm compression.

 

[littlepigeon]

Will the cooker actually be in contact with the pipe?

I'm hoping not. The cooker has quite a big recess at the back. Its max depth is 600mm, this is the very top. However most of the unit is only 530mm. However due to the way the plasterer has dry lined my room I am losing a bit of that void the closer I get to the floor. :/

We havent actually got the cooker yet to try. I think i may have to just get the cooker in the room and see how bad it will be then take it from there.

Copper pipe maybe a good idea. is there any other type of metal i could use that maybe not so expensive?

Am I definitely going to run into problems if i use 32mm pipe? This isnt a waste that joins any other wastes, its just straight from the washing machine running about 3.5 to 4 meters, out of the external wall and down to a drain. What is 32mm plastic pipe used for?

 

[Hugh Jaleak]

32mm is for basins and bidets, it's not of sufficient diameter to handle to flow when a washing machine pumps out. Could use steel pipe, but I think that would need supporting though due to weight, and that presents problem of how to support without it being proud of the wall.... Copper is straightforward to connect, IIRC Polypipe pushfit waste will squeeze onto copper of similar size, so compression waste would fit ok.

Not sure of the layout from your description, but an outside toilet = drain. Possibility of connecting it into there? To get through the wall, either hire a suitable drill and appropriate size core bit, or the old fashioned method. Lump hammer and cold chisel, then make good afterwards.

 

[Madrab]

32mm waste pipe is for basins in bathrooms and cloakrooms so a smaller volume of water over a smaller distance compared to a full washing machine being pumped empty over 4m.
Unfortunately LP, 40mm is really as small as you want to go to avoid the capacity of the pipe being exceeded when evacuating the volume and type of water (foaming) being pumped and avoiding it backing up.

Or Wot Hugh said .. lol..

 

[big-all]

if you are behind the range assuming dot and dab cut a track into the plaster board that will give you about 20mm ??

 

[Helzabells]

Hi I no this was a while ago but I wondered what you did in the end. I have the same problem now, my washing machine pipes need to go behind my 100 cm range cooker? Did this turn out to be ok or did the heat of the oven desroy the pipes. Thanks

 

[Agile]

32mm is for basins and bidets, it's not of sufficient diameter to handle to flow when a washing machine pumps out. Could use steel pipe, but I think that would need supporting though due to weight, and that presents problem of how to support without it being proud of the wall.... Copper is straightforward to connect, IIRC Polypipe pushfit waste will squeeze onto copper of similar size, so compression waste would fit ok.

That is quite true but only applies to a gravity drain.

A washing machine outlet pipe can be extended ( without an air break ) for several meters in the 21.5 mm plastic waste or in 22 mm copper without any problems.

So your solution will probably be to extend the 22mm pumped WMC outlet pipe.

Tony