This has happened after the day of heavy rain in Melbourne. Any advice on what to do next is much appreciated!
Hi @loudee
The pipework there doesn't look to be in good condition and if there is a crack or break, your soil could have been washed away down the pipe. The problem as I see it is that this is unlikely to be a stormwater pipe as it seems to come from under the slab/foundations with no sign of a nearby downpipe in the pictures. I'm afraid you have little option other than call a plumber with this one.
However all that said, there is nothing stopping you from excavating the area to check as there also seems to be a vent pipe in the path (small grey pipe amongst the pebbles). The pipe could just possibly be stormwater and be pre installed coming from somewhere else around the house and with the signs of erosion further afield than the immediately obvious, what could have happened is that there is a DIY soakwell under there and the pressure of the water has lifted the lid of it allowing the soil to wash into it. If so, you could open it up and clean it out then check the vent pipe isn't blocked (if that is what it is).
Welcome to the Bunnings Workshop community @loudee. It’s great to have you join us.
It looks like a fairly substantial void has opened up beneath the decorative stone, and I can also see what appears to be pipework in the affected area. Given this happened immediately after heavy rain, I’d be concerned that water may have washed soil away beneath the surface rather than this simply being some minor settling.
I wouldn’t recommend just filling the hole with soil or gravel yet, as it would be important to establish where the water is coming from and whether there has been any damage to, or leakage from, the nearby pipework. If the cause isn’t addressed first, anything used to fill the void could simply wash away again.
I’d suggest carefully removing some of the loose decorative stone so you can get a better idea of the extent of the void, without digging around or disturbing the pipes. If you’re unsure what those pipes are for, or the void extends beneath the concrete or nearby paving, I’d recommend having a plumber or suitably qualified professional inspect the area. They can check the drainage and pipework and determine why the soil has been washed out before the area is backfilled and compacted. Please be aware that plumbing and drainage work must be carried out by a licensed plumber.
Please keep us updated with what you find.
Mitchell
Thank you both for your helpful advice, I appreciate it. Have called a drainage plumber to inspect this
That's a smart move @loudee, especially since it is so close to your foundation and with the possibility of plumbing involvement.
@loudee
Just a quick point to discuss with the plumber if it does turn out to be a DIY soakwell, should it be that close to the house?
