Sink waste resting on batten?

[Albumen]

The service void at the back of my new units is 43mm, according to the manufacturers. Correct that, it's 40mm, just measured it.

I need to run the waste from the sink behind a couple of units. As it is it looks like I'll have to chase out a bit of plaster, and any clips aren't going to fit in the void. So I thought a long piece of timber, <40mm deep, screwed to the wall for the waste to sit on.

Any problems with that as an idea? The waste can't go anywhere, sideways, as it'll be held be the units.

Or do people usually run the waste through the middle of the units. Seems a bit barmy having a service void which is exactly the same size as a standard waste pip.

Thanks.

 

[PrenticeBoyofDerry]

I don't see any issue with a timber support for the waste pipe, is it not possible to get that extra 3mm-5mm required, by cutting the back of the carcass a little to accommodate the pipe?

 

[Albumen]

Thanks.

This waste will be running horizontally. Well, apart from the required fall.

The side walls of the carcasses are going to have to be cut anyway. It's the back wall of the units that's the problem, it's too close to the wall.