Do I need to bother with traps at all??

[BuilderDan]

I'm building a new off-grid house. I have a septic tank exclusively for WC's, but the bathroom has its own independent stone & gravel soak away which is straight into the ground and not connected to the septic, and obviously not connected to any main drains etc. Therefore, no sewer gases etc. Which makes me think - in this specific case do the bathroom fittings (sink, shower, and bath) even need traps??

 

[ShaunCorbs]

Yes else you will get bugs coming up and through your outlets

 

[BuilderDan]

Yes else you will get bugs coming up and through your outlets

Good point, thank you. Would it be acceptable to have just a single trap just before the soak away? (i.e. a trap that would serve the sink, bath, and shower, without having individual traps at each unit) I'm not trying to cut corners, it's just that the concrete floor slab is already cast with shower drain pipe set in, would need to break up floor in order to install a trap (and then would never be able to access that trap in future without breaking up tiles and concrete). I do however have access to the main pipe just before it goes into the soak away, and could easily fit a manhole cover and accessible trap in this location.

 

[ShaunCorbs]

You could do aslong as it’s accessible

 

[MikeJhn]

The lack of knowledge shown by casting the slab without any forethought for service, is quite worrying for the rest of the off grid build, do you have any professionals involved, and I don't mean builder Bob from the pub.

 

[BuilderDan]

quite worrying

Don't worry Mike

do you have any professionals involved

Yes