Toilet Buying Guide Australia: S-Trap vs P-Trap, Set-Out & Toilet Styles

Most wrong purchases happen for one reason: people pick the style first and the plumbing second. Flip it.

Do this in order

  1. Confirm trap type (S-trap, P-trap, skew trap, universal trap)
  2. Measure set-out (the number that makes or breaks compatibility)
  3. Choose the style (close coupled, back-to-wall, wall-hung)
  4. Then choose seats and features (soft close, quick release)
Pro tip: Always measure from the finished surfaces (tiles), not studs or bare sheeting. That extra 10 to 15mm can be the difference between “fits perfectly” and “why is this not lining up”.

When you’re ready to browse, start with your full range of toilets.

Step 1: Know your trap type (S-trap, P-trap, skew trap, universal)

S-trap (floor outlet)

Waste goes into the floor.

Look for: the pipe disappearing into the tiles.

P-trap (wall outlet)

Waste goes into the wall.

Look for: the pipe going straight back into the wall behind the pan.

Skew trap (offset outlet)

Used when the outlet is offset to one side. This is the classic “my waste isn’t centred” scenario.

Universal trap (Uni-trap)

Many modern toilet suites are now universal trap, meaning they can be configured for either S-trap or P-trap. If you want more style options, this is worth looking for.

(We’ll publish a deep dive next: S-trap vs P-trap vs skew trap explained.)

Step 2: Measure toilet set-out properly (don’t mix up horizontal vs vertical)

Set-out is the measurement that decides whether a toilet will physically line up with your outlet.

Two quick rules

  • S-trap set-out is horizontal: measure from the finished wall (tiles) to the centre of the floor outlet.
  • P-trap set-out is vertical: measure from the finished floor (tiles) to the centre of the wall outlet.

(We’ll publish the step-by-step next: How to measure toilet set-out in Australia.)

Step 3: Choose the toilet style that matches your bathroom and install reality

Once trap type and set-out are clear, style selection becomes easy.

Close coupled toilets

The classic “pan + cistern” setup.

Best for: simple replacements, straightforward installs, easy maintenance access.

Back-to-wall toilets

Sleeker look where the pan sits flush to the wall.

Best for: modern bathrooms, a neater look, easier cleaning around the base.

Wall-hung toilets

The pan mounts to an in-wall frame.

Best for: full renovations, maximum floor cleaning, premium finish.

(We’ll publish the comparison next: Back-to-wall vs close coupled vs wall-hung.)

Step 4: Rimless, comfort height, and the checks Aussies should make

Rimless toilets

Rimless usually means easier cleaning access because the bowl design is simplified. The “worth it” part comes down to how much you value easy cleaning.

Comfort height vs standard height

Comfort height can feel better for taller users or anyone who wants an easier sit and stand. Standard height can feel more natural for kids or smaller bathrooms.

WELS star rating (Australia)

Check the WELS star rating if you want to compare water efficiency between options. It can make a real difference to water use over time.

Step 5: Toilet seats, shape, and the features people regret not getting

Even if you’re buying a full suite, seats matter.

The two big seat mistakes

  • Wrong shape (D-shape vs oval)
  • Wrong fix type (top-fix vs bottom-fix, depending on the pan)

Features that are actually worth it

  • Soft close: stops the slam and feels premium day-to-day
  • Quick release: makes proper cleaning way easier

If you’re replacing just the seat, start in toilet seats.

(We’ll publish a full DIY next: Toilet seat replacement guide.)

Quick decision cheat sheet

  • If you’re not renovating and want a simple swap, a close coupled style is often the easiest path.
  • If you want a modern clean look without going full in-wall, back-to-wall is usually the sweet spot.
  • If you’re doing a full renovation and want max cleanability, wall-hung is the premium play.
  • If you’re unsure on compatibility, trap type + set-out come first, always.

Browse the range once you’ve confirmed your measurements with toilets.

FAQs

Can I replace a toilet without moving plumbing?

Often yes, if you match trap type and set-out. The more closely you match what’s already there, the smoother the install.

Are S-trap and P-trap interchangeable?

Not directly. They’re different outlet directions. Some installs can be adapted, but it’s usually cleaner to buy the correct configuration for your setup.

What is a skew trap toilet?

A skew trap is used when the outlet is offset to one side rather than centred, common in older bathrooms or where plumbing was routed around constraints.

What’s the easiest toilet to keep clean?

Back-to-wall and wall-hung styles usually win for cleaning around the base. Rimless designs can also make bowl cleaning easier.

Are toilet seats universal?

Not always. Shape, hinge spacing, and fix type matter. If you’re replacing a seat, measure first, then shop toilet seats.