Shower drains have a hard job: they take a steady stream of hair, body oils, soap scum and increasingly thick shampoo and conditioner residues. Hair snags on the waste fitting, soap binds it into a felt-like mat, and the mat catches everything that follows.
Start with the simple checks:
- Pull the grate and clean out the visible waste and trap — a bent wire or drain-cleaning tool will hook out surprising amounts of hair.
- Flush with hot (not boiling) water to soften soap residue.
- Fit a hair catcher over or in the waste — the cheapest drain maintenance there is.
When it is more than the trap: if the shower still drains slowly after cleaning, or the slowness comes with gurgling, smells, or other slow fixtures, the restriction is further along — a branch line clogged with soap and hair, or a partial blockage in the main drain. Showers are usually the lowest fixture in the bathroom, so they are often the first place a main-line problem shows itself.
Chemical drain cleaners are worth avoiding, particularly in older pipes: caustic products generate heat that can damage PVC and old joints, they rarely clear a compacted hair mass, and they make the drain hazardous for whoever eventually has to clear it properly. Mechanical clearing — a drain machine or jetter — removes the blockage rather than burning a hole through part of it.