Why does my bathtub faucet drip after I turn it off?

A dripping bathtub faucet is almost always caused by worn internal components that no longer create a watertight seal when the handle is in the off position. The good news is this is one of the more straightforward plumbing repairs.

The most common cause depends on your faucet type. Older two-handle faucets (separate hot and cold) use rubber washers or seats that wear down over time. Every time you turn the tap, that washer compresses against a metal seat — after thousands of cycles, it hardens, cracks, or deforms and can no longer stop water flow completely. Single-handle faucets typically use a cartridge or ceramic disc instead, and when those fail, you get the same dripping result.

Mineral buildup is a contributing factor in Ottawa homes, since our water supply can leave calcium and lime deposits inside the valve body. This buildup accelerates wear on washers and cartridges, and can also prevent components from seating properly even when they're not fully worn out yet. If you've noticed white or greenish crust around your faucet, mineral scale is likely part of the problem.

A slow drip wastes more water than most people realize — even 10 drops per minute adds up to roughly 3,000 litres per year. Beyond the water bill, a dripping faucet that's ignored can eventually worsen into a steady stream, and the constant moisture around the tub can lead to caulk failure and water damage behind the tile.

For Ottawa homeowners, a bathtub faucet repair typically runs $150 – $300 depending on the faucet type and whether parts need to be ordered. Cartridge replacements on popular brands like Moen or Delta are usually straightforward. Two-handle faucets with corroded valve seats may require seat grinding or full valve replacement, which adds some time and cost.

On the DIY front, replacing a cartridge on a single-handle faucet is something a handy homeowner can attempt — shut off the water supply to the bathroom, remove the handle, pull the cartridge, and replace it with an exact match from a hardware store. However, if you're dealing with an older two-handle faucet, corroded parts, or you're not confident identifying the faucet brand and model, it's worth calling a pro to avoid making the problem worse.

If the drip has been going on for a while or you notice the faucet is getting harder to turn off fully, don't wait — the valve seat may be damaged and a simple washer swap won't fix it. For a free estimate on your bathtub faucet repair, reach out to Ottawa Pro Plumbing and we'll get it sorted quickly.