Mr. Clog Plumbing

Drain Relocation & New Drainage for Renovations, Sydney

Moving a bathroom, toilet, kitchen or laundry, or building an extension over an old drain? We relocate drains and lay new drainage to the new layout, including under concrete slabs.

No surprise bills: $0 call-out and a fixed price before any work starts.

Our guarantee: 12 months on our workmanship, in writing. What it covers

When a bathroom, toilet, kitchen or laundry moves, its drainage has to move with it, and every new waste still needs to fall to the sewer. When an extension is built over an existing sewer or stormwater line, that line may need to be moved out of the way first. In Parramatta, a bathroom was being moved to a new location, so it needed new drainage: we saw-cut the concrete slab, installed the new drainage to the new bathroom location, and backfilled the trenches with 11 mm blue metal. We find where the existing lines run, plan the new route with the right fall, lay it, connect it into the existing sewer, and test it. Where the work is near a Sydney Water pipe, their approval may be needed first. You get a fixed price before we start, and 12 months on our workmanship.

  • Drains relocated for new layouts
  • New drainage for extensions and added bathrooms
  • Concrete slabs saw-cut for new drainage
  • New lines connected into the existing sewer
  • Stormwater moved around extensions
  • Existing lines found on camera first
  • Fixed price quoted before we start
  • 12 months on our workmanship

Fixed price quoted before we start. $0 call-out fee.

The toilet has the biggest waste in the house, so moving it is the main drainage decision in a bathroom relocation. Showers, basins and baths follow.

A sink or laundry tub on the other side of the room, or an island bench, needs a waste with fall to the drain.

Many extensions are built over the old sewer or stormwater line at the back of the house. Moving the line before building means it can still be reached later.

New drainage from the new room, connected into the existing sewer.

The slab is saw-cut along the new route, the trench dug out, the new drainage laid with fall and connected, then backfilled, ready for the slab to be patched. That's what we did in Parramatta.

If there's room under the floor, new drainage can often run through the subfloor, which is simpler.

The limit is fall: the further a waste travels, the deeper it needs to start. We work it out before you settle the layout.

The sewer service diagram shows the general route, and a CCTV camera confirms where the line actually is.

If the old line is cracked or rooted clay, replacing it while the ground is open is usually far easier than after the extension is built.

Inspection openings and the overflow relief gully must stay accessible. If the new work covers them, they get moved.

Building over or near a Sydney Water sewer main can need their approval first, where required. Our Sydney Water applications page explains more.

From the Job Sheet

Parramatta ·

The problem

The bathroom was being moved to a new location, so it needed new drainage.

What we did

We saw-cut the concrete slab, installed the new drainage to the new bathroom location, and backfilled the trenches with 11 mm blue metal.

Saw-cut trench in a concrete slab running out to the yard for new drainage
Trench cut through the concrete floor slab for a new drainage line
New PVC drainage and risers in the floor of a relocated bathroom

How It Works

01

Camera and locate the sewer and stormwater, and check the sewer service diagram.

02

The new drainage laid out with fall to where it connects.

03

Slab saw-cut or trench dug, new drainage laid and connected.

04

Tested, inspected where required, then backfilled.

Common Questions

Usually, yes. The new waste needs to fall to the sewer, so it depends on the distance and the floor. On a concrete slab, it means cutting the slab.

Yes. We saw-cut the slab, lay the new drainage with fall, connect it and backfill the trench. In Parramatta we did this for a relocated bathroom.

Sometimes, but the line may need to move first, access has to be kept, and if it's a Sydney Water main their approval may be needed. We find where the line runs before you finalise the plans.

It has to stay accessible and in the right position for the house. If the new work covers it, we relocate it.

If the camera shows cracked or rooted pipe, it's usually worth it while the ground is open.

It depends on the distance and the floor. We give you a fixed price before we start, with a $0 call-out fee.

from 35 Google reviews
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We recently used Mr Clog Plumbing for our granny flat in Guildford and couldn't be happier with the service. Everything was handled professionally from start to finish, with great communication and workmanship…
George A.Guildford · October 2026
Absolute legend. Turned up on time, sorted the problem quickly and didn’t charge a fortune. Super easy to deal with and cleaned up after the job too. Will definitely be using him again and would happily recomme…
Samantha M.May 2026
Turned up on time and honest service, couldn’t ask for much more.
Danny D.May 2026

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