No water trap in shower on a slab

Gnomes · Oct 23, 2023 7:26 pm

So, a while back, some smells were coming up through the shower drain in my unit. A plumber came to take a look and said it had been built without a water trap / u-bend so the smells of the sewer were coming up through the drain.

As the unit is on a slab, he said it would cost $15,000 to get to the pipes, install a u-bend, and fix the bathroom back up.

I installed one of these instead: https://tinyurl.com/3eufhycd and haven't had much of an issue since.

Now though, I'm selling the unit and I'm not sure my makeshift u-bend solution would be considered up to code. Trying to figure out if it's better to get it fixed before I sell, or just declare it somewhere.

And was I over quoted initially by the plumber? I know fixing plumbing in a slab is not straightforward, but it does seem like a lot to me. What would be a reasonable sort of cost to fix this?

chippy · Oct 23, 2023 7:36 pm

How old is the unit?

Gnomes · Oct 23, 2023 7:38 pm

Built in 2016

chippy · Oct 23, 2023 7:46 pm

How did the plumber ascertain that there is no trap? Did he simply look in the drain or did he insert a scope?
A trap doesn't necessarily have to be straight under the waste.
It would be unusual for it not to have one. That doesn't explain the smell

Gnomes · Oct 23, 2023 7:50 pm

He put a camera down there. He said he couldn't see where the water was gathering so it looked like there was no water trap.

chippy · Oct 23, 2023 8:10 pm

The trap normally wouldn't be in the slab. The penetration goes straight through and the traps are underneath the slab. That often means it's in your neighbour belows ceiling.
There is often a manhole in that ceiling so you can access it or at least have a look.

Gnomes · Oct 23, 2023 8:13 pm

Ah, no, it's a one storey unit at the back of 5. The shower is right on the slab which is on the ground.

chippy · Oct 23, 2023 8:29 pm

Ah sorry I thought it was a multi storey unit.
Do you have a floor waste?
Sometimes the shower (along with the basin) will run to the floor waste and the trap will be there.
If you run the basin can you hear water running in the floor waste.
Ultimately if there is no trap the plumbing is non compliant and I'd be making enquiries around who did the plumbing originally. It really should have been followed up as soon as the issue was raised.

Gnomes · Oct 23, 2023 8:37 pm

Yeah, I did that at the time. The building work was just out of warrantee, and because it's part of the build, not a leak or an accident, insurance doesn't cover it either. Not sure I'd know what to listen for with the floor waste. Would another plumber be the way to go here, do you reckon? See if there is something else going on? This guy was actually the second opinion, because the first guy just looked at it and declared he couldn't see an issue (he didn't use a scope though).

chippy · Oct 23, 2023 9:06 pm

If you have a floor waste, turn on your sink and put your ear down to the central floor waste and listen. If you can hear water running then they all connect there. If you can remove the drain cover and shine a light down there you may be able to see the water running. If you can then that is where your trap is and all the wastes including your shower probably run to that which removes the need for a trap under the shower.
You could get a second or third opinion, it would be a surprise that a trap wasn't installed but mistakes happen.

chippy · Oct 23, 2023 9:06 pm