Domakihub Replace a Bath Waste and Overflow Assembly the Right Way
A practical guide to fitting a new bathtub drain and overflow kit without leaks.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
A corroded or weeping bath waste and overflow assembly is one of the most common maintenance issues in Greek homes, holiday rentals, and hotel rooms — and one of the most straightforward to fix yourself with the right parts and a little patience. The video above walks through the full fitting process on a real tub, while this guide breaks down each stage with clear instructions and the key details that matter most for a watertight result. Whether you are dealing with a slow leak behind an enamel tub or replacing a degraded plastic kit in a rental apartment, the principles are the same.
What the Assembly Actually Does
A bath waste and overflow assembly is the paired unit that controls drainage at two points on a bathtub: the main waste plug at the bottom of the tub, and the overflow outlet set into the tub end wall several centimeters above the base. The waste lets water out when the plug is pulled; the overflow is a safety drain that prevents flooding if the tub fills too high. Both are connected by a pipe that runs behind or beneath the tub and exits into the same standpipe or trap.
On older Greek properties, these assemblies are typically brass or chrome-plated brass and can corrode badly after years of contact with hard Attic or island water. On more recent builds and renovations, plastic click-clack or push-button kits are common. In either case, the assembly is sold and replaced as one unit — waste body, overflow plate, and connecting pipe all together.
Choosing the Right Replacement Kit
Before buying a replacement, measure the distance between the centre of the waste outlet and the centre of the overflow outlet on your tub. This centre-to-centre measurement, typically expressed in millimetres, must match the new kit or you will not be able to connect the two correctly. Most standard European soaking tubs use a 430–450 mm centre distance, but Italian and older Greek baths sometimes differ.
Also check whether your current waste uses a slotted or unslotted body — the slot allows overflow water to pass through the waste basket itself, which is relevant if the overflow pipe connects directly into the top of the waste rather than via a separate side port. When in doubt, bring the old assembly to the hardware merchant and match it physically.
How to Fit a Bath Waste and Overflow Assembly
- 1
Remove the Old Assembly
Turn off the water supply and drain any standing water. Unscrew the overflow cover plate from inside the tub — it is usually held by one or two Phillips screws. Then unscrew the waste body from below using a bath plug wrench or a large flat-blade screwdriver inserted into the cross of the waste grid. Once both are free, slide out the connecting overflow pipe from behind or beneath the tub. Clean away any old putty or silicone from the seating surfaces on the tub before continuing.
- 2
Dry-Fit and Check Alignment
Before applying any sealant, loosely assemble the new kit to confirm the overflow pipe reaches both outlets comfortably. The pipe should sit without tension — if it is being forced into position the connection points will not seal correctly over time. Some kits include an adjustable telescopic pipe; set its length now and tighten the locking collar hand-tight. This dry-fit step catches mismatches before you have committed any sealant.
- 3
Seal the Waste Body and Bed It In
Apply a ring of plumber's putty or the gasket supplied with the kit around the underside flange of the waste body — do not use both, choose one method and stick with it. If the kit comes with a rubber gasket, no putty is needed; simply press the gasket into place. Lower the waste body into the tub hole from above and press it firmly down. From beneath the tub, slide the rubber washer and then the plastic or brass backnut onto the threaded spigot and hand-tighten. Finish with a quarter to half turn using a wrench — overtightening cracks the tub flange on acrylic baths.
- 4
Fit the Overflow Plate and Connect the Pipe
Position the rubber overflow gasket against the inside of the tub around the overflow hole, making sure it sits flush with no folds. Press the overflow cover plate over it and drive in the fixing screws finger-tight at first so you can still adjust the plate centrally over the hole, then tighten fully. Connect the overflow pipe between the overflow outlet and the side or top port of the waste body, securing any compression fittings or push-fit connectors according to the kit instructions. The pipe must not be kinked or resting under lateral stress.
- 5
Test for Leaks Before Closing Up
Fill the tub to just above the overflow outlet and let it stand for five minutes, watching underneath with a torch for any drips at the waste backnut joint, the overflow gasket, and both ends of the connecting pipe. Then pull the plug and let the water drain fully, checking again as the flow runs. If you see a drip at the waste body, tighten the backnut a fraction more. If the overflow gasket weeps, the cover plate screws need to be tightened evenly. Only close up any access panel once the tub has passed a full wet test.
Rather have a pro handle it?
Get a vetted plumbing pro in your city — one number, booked in EN/EL/DE.
FAQ
- Can I replace a bath waste and overflow assembly without removing the bathtub?
- In most cases, yes. The waste body is accessed from inside the tub and the backnut is tightened from below through an inspection hatch, a gap in a bath panel, or by working under the tub. Removing the tub is only necessary if there is no access at all beneath the bath — rare in standard Greek bathroom builds but possible in some fully tiled-in freestanding tub installations.
- What sealant should I use around the waste and overflow on a Greek tub?
- For the waste body, traditional plumber's putty gives a reliable watertight bed that stays workable if you ever need to re-open the joint. Silicone sealant works too but is harder to remove cleanly later. For the overflow plate gasket, the rubber seal supplied with the kit is sufficient on its own — do not add silicone beneath a rubber gasket, as this actually reduces clamping pressure and can cause weeping. White sanitary silicone can be applied around the outer edge of the overflow plate as a cosmetic finish if a small gap remains between the plate and tub.
- How long does a bath waste and overflow assembly typically last?
- Brass assemblies in areas with moderately hard water — which covers most of mainland Greece and many islands — last 10 to 20 years before corrosion causes weeping. Chrome-plated brass fails at the plating edges first, allowing corrosion underneath. Plastic click-clack waste kits are less susceptible to corrosion but their rubber seals and click mechanisms wear out in roughly 8 to 12 years in a busy rental property. If the overflow plate is discoloured or the waste plug no longer holds water reliably, replacing the whole assembly at once is more cost-effective than patching individual parts.