Choosing the wrong waste is the most expensive mistake in a wet room installation. Not because the waste itself is costly, but because discovering the error usually means lifting the former, re-tanking, and re-laying the floor finish.
It comes down to two questions, and both need answering before you order. This guide walks through them, then gives you the compatible wastes for each AKW former and tray we stock.
The two questions that decide everything
- What is going on top? Tiles or vinyl safety flooring. These need different wastes, and they are not interchangeable.
- How much depth is there below the former? Measure this before ordering. It determines whether you can use a standard trap, need a low-depth one, or have to pump.
Question 1: tiled or vinyl?
This is where most installations go wrong.
Vinyl safety flooring needs a waste with a clamping ring. The vinyl is dressed into the waste and trapped between the clamp and the body, forming the watertight seal. Fit one of these under tiles and there is nothing for the clamp to grip.
Tiled floors need a stainless steel waste with an adjustable top plate. The plate rises to meet the tile and adhesive bed, and the seal is made by the tanking membrane bonded to the waste flange. Fit a vinyl-clamping waste under tile and you will get a leak — not immediately, but eventually.
A tiled wet room also needs a tanking kit. That is not optional, and it is not the same job as the waste.
The short version: vinyl gets a plastic clamping waste. Tiles get a stainless steel waste plus tanking. Never mix them.
Question 2: how deep can you go?
The trap sits below the former, between the joists or in the floor void. Measure the clear depth you actually have, then pick a waste that fits it.
A deeper water seal resists odour backflow better, so use the deepest one your floor allows. A 50mm or 75mm seal is preferable to a 19mm seal where there is room.
| Waste | Depth below former | Water seal | Floor finish |
|---|---|---|---|
| PGTF 15mm Pumped (25101) | 35mm | Pumped | Vinyl |
| PW50 Pumped Waste (25122 / 25405) | 44mm | Pumped | Braddan trays |
| Silentflow+ PGTF 22mm (25414) | 48mm | Pumped | Vinyl |
| DW90 Low Depth Dry (25418-UK / 25419-UK) | 53mm | Dry trap | Tiled / Vinyl |
| GW90-2 Low Depth Wet (25498-UK / 25499-UK) | 53mm | 50mm | Tiled / Vinyl |
| GW19 Gravity (25125) | 93mm | 19mm | Braddan trays |
| TFWA with GW19 (25129) | 97mm | 19mm | Vinyl |
| GW50 Gravity (25126) | 124mm | 50mm | Braddan trays |
| TF75 1 Part Gravity (25106) | 125mm | 75mm | Vinyl |
| SS-TF75 Stainless (LB00101) | 125mm | 75mm | Tiled |
| TFWA with GW50 (25124) | 128mm | 50mm | Vinyl |
Gravity or pumped?
Gravity is always the first choice. Fewer parts, no power supply, nothing to service, nothing to fail.
You need a pumped waste when you cannot achieve a fall to the soil stack — typically a ground-floor flat, a solid concrete slab that cannot be cut, or a bathroom a long way from the stack. A pumped gulley lifts waste water and discharges it through 15mm or 22mm pipework.
Two things people forget about pumped wastes: they need a fused spur, wired by a qualified electrician, and they make noise. AKW's Silentflow+ PGTF was designed specifically to reduce that, using dual chambers and baffles, so it is worth the small premium in a domestic bathroom.
There is also a third option on the Braddan tray: a factory-fitted upward discharge waste. The pump sits entirely within the 40mm tray depth and pushes water upwards, so nothing at all goes below floor level. That is the answer for a genuinely unbreachable floor. It is a different tray rather than a waste you add — see the upward pumped Braddan.
Wastes by product
AKW Tuff Form
The Tuff Form takes the widest choice of any former we stock — twelve options.
Vinyl: TF75 1 Part Gravity (25106), TFWA adaptor with GW50 (25124) or GW19 (25129), DW90 low depth (25419-UK), GW90-2 low depth (25499-UK), Silentflow+ PGTF 22mm pumped (25414).
Tiled: SS-TF75 stainless (LB00101), SFWA stainless dot grate with GW50 (21318) or GW19 (21319), DW90 low depth (25418-UK), GW90-2 low depth (25498-UK).
AKW Tuff Form8
The Tuff Form8 takes the same waste family. Its advantage is elsewhere: a rotating octagonal plate giving up to 15 waste positions, including a central one. If your joists are awkward or unsurveyed, that flexibility is worth more than the waste choice.
Contour ShowerDec
The ShowerDec offers nine options.
Vinyl: CTW01 Contour Round 2 Part Gravity, TF75 1 Part (25106), TF75 Bottom Outlet (25408), PGTF 15mm pumped (25101), Silentflow+ PGTF 22mm (25414).
Tiled: Square Chrome 2 Part 50mm McAlpine gully (TSG52T150SSCON), SFWA stainless with GW50 (21318), PGTF stainless pumped (LB00104).
The TF75 Bottom Outlet is worth knowing about: it discharges straight down rather than sideways, which suits new-build concrete floors where the pipe drops vertically.
AKW Braddan shower trays
The Braddan is a tray rather than a former, with a central 50mm threaded outlet and five waste options: GW19 Gravity (25125) at 93mm depth, GW50 Gravity (25126) at 124mm, PW50 15mm Pumped (25122), PW50 22mm Pumped (25405), and the factory-fitted upward discharge version.
On a timber floor with tight joists, the GW19 is usually the one that fits.
Five mistakes worth avoiding
- Ordering the waste before measuring the floor void. The single most common cause of a returned waste.
- Using a vinyl waste under tiles. It will not seal reliably. This is the expensive one.
- Forgetting the tanking kit. A stainless waste alone does not make a tiled wet room watertight.
- Choosing a 19mm seal when there is room for 50mm. Shallower seals are more prone to odour backflow, especially in a shower used only occasionally.
- Specifying a pumped waste without planning the electrics. It needs a fused spur, and that needs to be in the first-fix plan.
Frequently asked questions
Can I change the waste later? Not realistically. The waste is bonded into the former and sealed under the floor finish. Changing it means lifting the floor.
What if I have almost no depth below the floor? Look at the low-depth options first — DW90 and GW90-2 both need only 53mm. Below that, you are into pumped wastes, or the factory-fitted upward pumped Braddan where nothing sits below the tray at all.
Do gravity wastes need cleaning? Yes. All the gravity wastes here open from above for cleaning and rodding, and have a built-in strainer that lifts out to catch hair and debris.
Can I use a standard shower trap instead? No. Wet room formers take a specific waste designed to bond to the former and clamp the floor finish. A standard trap will not seal.
Is a waste included with the former? Only if you select one. Every former and tray on our site has a "No Waste" option for installers supplying their own.
Still not sure?
If you can tell us your floor construction, the depth available below the floor, and whether you are tiling or laying vinyl, we can confirm the right waste before you order. Browse the full range of wet floor formers and wet floor former wastes, or get in touch.