Extra-flat tray recessed flush with the floor or raised tray on top? The choice depends on your screed, your drainage and the look you want. Add to that the material and slip resistance. Here is how to decide without getting stuck at fitting time.
Extra-flat recessed vs raised tray
The raised tray sits on top of the finished floor: simple fitting, adjustable feet, ideal in renovation when you don't want to touch the screed or the existing drain. It creates a small step at the shower entrance.
The extra-flat tray (2.5 to 3.5 cm) can be laid on the floor or recessed for a flush-with-the-floor finish (walk-in shower). The look is clean and step-free, but it requires planning the recess and drainage from the screed stage.
- Raised: easy fitting, ideal renovation, slight step
- Extra-flat laid: low profile without major works
- Extra-flat recessed: flush-with-the-floor finish, step-free
Which material: resin, acrylic or ceramic
Resin / Solid Surface (mineral filler) is the high end: warm-to-the-touch surface, slip-resistant, cuttable to size, concrete or slate finishes, very durable. It is currently the most common choice in extra-flat.
Acrylic (reinforced) is light, economical and easy to fit, but more prone to scratches and less premium-looking. Ceramic (glazed stoneware) is very durable and easy to maintain, but heavy, cold and brittle in transport.
- Resin / Solid Surface: premium, warm, slip-resistant, cuttable
- Acrylic: light and affordable, more scratch-prone
- Ceramic: robust and easy to maintain, heavy and cold
Drainage and trap in extra-flat
The sensitive point of extra-flat is drainage: the low height requires an extra-flat trap with sufficient flow (aim for at least 30-40 L/min to keep up with a rain shower). An undersized trap lets water stagnate.
Think about the slope: a tray with integrated slope avoids puddles. For a flush-with-the-floor recess, the trap's accessibility for maintenance (removable grating) is essential — otherwise unblocking becomes a worksite.
Slip resistance, dimensions and safety
Safety is read on the slip-resistance class. The PN (bare feet) standards go from PN6 to PN24: for a family bathroom, aim for at least PN12, even PN18 for seniors or children. A surface that is too smooth becomes slippery when soapy.
On dimensions, formats range from 80×80 to 90×120 and beyond, in square, rectangle or quarter-round. Many resin trays are cuttable to size, which is valuable in existing alcoves.
Which brands to choose
In BE, the safe bets are Arblu, Jacob Delafon, Schedel, Geberit, Riho and Novellini, covering extra-flat resin, acrylic and recessing solutions.
Choose according to the material + exact dimensions you need, the slip-resistance class and the compatibility of the supplied trap. Also check the availability of a removable grating or trap cover for maintenance.
Frequently asked questions
Shower tray extra-flat or raised?
The raised tray is simpler in renovation: it sits on top without touching the screed or drain, with a slight step. Extra-flat offers a low profile and, recessed, a flush-with-the-floor, step-free finish, but you must plan the recess and drainage from the screed stage.
What height for a raised tray?
A raised tray is generally between 6 and 18 cm high depending on the model and adjustable feet. You must allow for the trap height beneath. Extra-flat measures about 2.5 to 3.5 cm, which greatly reduces the step but requires a suitable extra-flat trap.
Shower tray in resin or acrylic?
Resin (Solid Surface) is higher-end: warm to the touch, slip-resistant, cuttable to size and very durable, but more expensive. Acrylic is light, economical and easy to fit, but more scratch-prone and less premium-looking. For intensive use and a fine finish, resin is preferable.
Can you fit an extra-flat tray on an existing screed?
Yes, provided you have the necessary height under the tray for the extra-flat trap and the drainage slope. Without a recess planned in the screed, a flush-with-the-floor finish is difficult: you then opt for either an extra-flat tray simply laid on top, or a classic raised tray.
