Overflow
The opening near the top of a bathtub that drains excess water to stop it spilling over. Think of it as the tub's quiet safety valve: you rarely notice it until the day it earns its keep.
What it means
An overflow is a small opening set into the tub wall a little below the rim. Inside the tub body it connects to the waste, so when the water level climbs high enough to reach it, the excess is drawn away down the drain instead of over the edge. If a mixer or filler is left running, the overflow buys you time before the bathroom floor gets involved.
It also quietly sets the practical maximum water level of a tub. Fill past the overflow and the extra water simply drains away, so the height of the opening decides how deep a soak can actually be. That is why two tubs of the same length can feel quite different once you are in them.
The overflow is not the same thing as the drain. The drain sits at the lowest point and empties the tub when you release the plug; the overflow sits near the top and only works when the water rises too high. In a freestanding bathtub, both ultimately feed the same waste route out of the tub.
In a Singapore home
Singapore bathrooms are more forgiving of splashes than most. HDB and condo bathrooms are built as wet areas, with a waterproofing membrane under the tiles and a floor trap in the floor, so the occasional slosh over the rim drains away rather than soaking into the structure. The overflow still matters, though: it is the difference between a splash and a tap left running unattended.
In a freestanding format, all the waste water, whether from the drain or the overflow, leaves the tub through a flexible drainage outlet that connects to your existing floor trap, so no new plumbing is needed. During a HERA installation the team connects the drainage and performs a leak test before leaving, and the installation itself usually takes around 30 to 45 minutes. The 1-year warranty covers the drainage components along with the acrylic surface and internal frame.
If you want to see how a particular model handles its waste and water level, the bathtub guide covers the full range of 14 models from 800mm to 1700mm, and the team can talk you through the details of any tub you shortlist.
Quick questions
What does a bathtub overflow actually do?
It acts as a relief point. If the water level rises to the overflow opening, the excess is carried away to the waste instead of over the rim. It is a backup against a tap left running, not something to rely on, so a filling bathtub should still not be left unattended.
Is the overflow the same as the drain?
No. The drain, also called the waste, sits at the lowest point of the tub and empties it when you release the plug. The overflow sits near the top of the tub wall and only comes into play when the water rises too high. In most designs both feed into the same waste outlet.
Where does the waste water go in a freestanding bathtub?
In a freestanding bathtub, waste water runs through a flexible drainage outlet into the existing floor trap in your bathroom floor, so no new plumbing is needed. During a HERA installation the team connects the drainage to your floor trap and performs a leak test before leaving.
Related terms
Curious how a tub drains without renovation?
Message us on WhatsApp and the team will walk you through the drainage setup for any model, usually within 15 minutes during showroom hours, or start with the bathtub guide.