How to mount or replace a toilet seat (no plumber needed)

A toilet seat wears out, yellows, cracks, or works loose over time — sooner or later, everyone ends up replacing one. Good news: it's one of the simplest DIY jobs in the house. No water to shut off, no pipes to touch — just two screws and 10 to 15 minutes. Here's how to choose the right one and mount it properly.

Measure before you buy

A seat that doesn't match your bowl means a trip back to the store. Before ordering, take three measurements:

1. The hole spacing (entraxe) — the distance between the two fixing holes at the back of the bowl (typically 14 to 18 cm). This is THE measurement that decides whether the seat will fasten correctly.
2. Bowl length and width — from the front edge to the fixing hole, and the width at its widest point. Too small leaves gaps; too big overhangs the rim.
3. Shape — oval (most common) or D-shape (straighter back edge, common on newer wall-hung bowls).

Tip: if you're unsure, remove the old seat and bring it to the store, or photograph it next to a tape measure.

Fixation types

There are two main systems, and you need to buy the right one:

• Top-mount fixation — screws tighten from above the seat, with nuts hidden under small caps. The most common system today, and practical when access from below is tight — especially on wall-hung bowls where the back sits close to the wall.
• Bottom-mount (classic nuts) — nuts are screwed on by hand or with a wrench from underneath the bowl. The traditional system, still widely used in Tunisia.

Check how your old seat is fixed before buying a new one — the two systems aren't interchangeable without an adapter.

Tools

No need for a full toolbox:

• A screwdriver (Phillips, sometimes flat depending on the model)
• A wrench or pliers if the nuts are hard to reach by hand
• Gloves (the back of a bowl isn't always the pleasant part to handle)
• White vinegar if the old fixation is caked in limescale

Step by step

1. Remove the old seat. Under the bowl, unscrew the nuts by hand or with a wrench. If they're stuck with limescale, spray white vinegar, wait 5-10 minutes, then try again. Once the nuts are off, lift the seat away from the back.

2. Clean the ceramic. With clear access, thoroughly clean the fixation area and the back of the bowl — it's the spot that collects the most grime and never gets properly cleaned once a seat is in place.

3. Present the new hinges. Most modern seats have adjustable-spacing hinges: set them to match your bowl's hole spacing before tightening anything.

4. Insert the screws and tighten. Firm but not excessive — over-tightening can crack the ceramic or break the plastic hinge. Hand-tight first, then a light extra turn with a wrench if needed.

5. Test the alignment. The seat should sit centered on the bowl with no side play. For a soft-close model, let it drop on its own from the raised position: it should descend slowly and silently, never with a bang.

Soft-close seats (frein de chute)

Soft-close prevents the loud bang and, more importantly, the cracks that build up over time from repeated impact. It's a small extra cost that pays for itself quickly, especially in a house with kids. Another practical perk: on most models the seat clips off in one motion for deep cleaning, without redoing the fixation. We carry Olympia and Milano soft-close seats — see Toilet Seats for the full range.

Common issues

• Wrong hole spacing or size — the seat won't fasten or overhangs the bowl edge badly. Recheck your three measurements before returning the product.
• Seat wobbles or shifts — retighten the nuts; if already fully tight and still loose, add washers to take up the play.
• Hinges yellowing — common with harsh cleaners or undiluted bleach; use a mild cleaner on plastic hinges.
• Soft-close too fast or still bangs — the mechanism is sometimes faulty out of the box; that's a valid reason to exchange it.
• Nuts unreachable or hidden — typical on wall-hung bowls with tight clearance; a top-mount seat solves this on the first try.

Changing a toilet seat is genuinely 10 minutes of work for a result you notice immediately. Browse our toilet seats — delivery throughout Tunisia, cash on delivery.