Your shampoo niche is a hole cut into your shower's waterproofing

Everyone wants a niche. It is cleaner than a caddy hanging off the shower head and it looks built in, because it is. But think about what it actually is: a hole cut into the one wall in your house that gets soaked every day.

The wall around it is waterproofed. The niche has to be too, on every face: the back, the sides, the top and the bottom, plus the corners where they meet the wall.

Where niches fail

• The corners. Inside corners are where a membrane is easiest to miss and hardest to check once tile is on.
• The bottom. A flat shelf holds water against the grout. It should shed water forward, back into the shower.
• The seams. Where the niche box meets the wall board, the joint needs to be sealed like any other seam.

None of these are visible when the job is done. A badly sealed niche can look perfect for years while water works into the wall behind it.

What a good one looks like before tile

Before tile, the niche should be completely covered by the same membrane as the rest of the wet area, with no bare board showing at the corners. On my jobs the membrane is red, so a missed spot is easy to see.

Placement matters too

Put the niche on a wall that is not an exterior wall where possible, at a height you can reach, and out of the direct spray of the shower head so it is not taking the full stream all day. We decide that at the framing stage, before any board goes up.