Bathroom · DIY guide

How to replace a toilet seat

Replacing a toilet seat is the cheapest visible improvement in a bathroom and needs no plumbing knowledge at all. The only part that ever causes trouble is the old fixings.

  • DifficultyEasy
  • Time15–30 minutes
  • Materials$40–150

Legal to DIY in Victoria

Checked as at September 2026. Rules and prices change — confirm anything you are about to act on.

What you need

  • Replacement seat — measure first (see step 1)
  • Adjustable spanner
  • Flat screwdriver
  • Penetrating oil or a hacksaw blade for seized bolts
  • Gloves and a cloth

Step by step

  1. Measure before you buy

    Three measurements: the distance between the two bolt hole centres, the width at the widest point, and the length from the bolt line to the front tip. Most Australian pans take a standard fit but D-shape and compact pans do not. Photograph the pan brand stamped inside the bowl if there is one.

  2. Get the old fixings off

    Reach underneath and hold the nut while turning the top of the bolt. Plastic fittings often just snap off. Seized metal ones respond to penetrating oil and twenty minutes of patience — or, as a last resort, cutting the bolt with a hacksaw blade wrapped in tape to protect the ceramic.

  3. Clean the mounting area

    With the seat off you have access you will never have again. Clean the hinge recesses properly before the new seat covers them.

  4. Fit the new seat loosely

    Drop the bolts through, fit the nuts finger tight, then sit the seat down and check it is centred and square to the bowl before you tighten anything.

  5. Tighten evenly

    Nip both sides up alternately, firm but not hard. Ceramic cracks and it is not repairable. Most seats need a re-tighten after a week or two once the washers have bedded in.

Common mistakes

  • Buying before measuring
  • Overtightening and cracking the pan
  • Not checking the seat is square before final tightening
  • Forcing seized bolts and chipping the ceramic

When to stop and call someone

If the pan itself is loose on the floor, rocks, or weeps at the base, that is not a seat problem. A loose pan usually means failed sealing at the outlet and needs a licensed plumber before it damages the floor.

This guide is general information, not advice for your particular house. Rules change — check the current position with the Building and Plumbing Commission, Energy Safe Victoria and WorkSafe Victoria before you rely on it. Plumbing, gas and electrical work must be done by a licensed practitioner. If your home was built or last renovated before 1990, assume asbestos until it is ruled out — see what a strip-out finds.

Doing this in an older Melbourne home?

What you find behind the wall depends a lot on when the house went up, and that varies suburb by suburb. If the job turns out to be bigger than a weekend, these pages set out what we usually find and what a full renovation costs there:

See every suburb we cover →

More DIY guides

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