The complete guide
Getting shower storage to stay on the wall
Why shower storage fails
Shower storage has a reputation for not lasting, and it is usually the fixing rather than the shelf that gives up. Suction cups depend on a vacuum that warms and cools every time the shower runs, and eventually one lets go, normally with a full bottle on it. Racks that hang off the showerhead swing whenever you reach past them and drip onto the same spot until the grout stains.
Fixing to the wall solves both. The question is how you attach it without making holes.
Why not drilling matters
Behind the tile in a modern bathroom there is a waterproof layer, either a membrane or a tanking system. It exists so water that gets past the grout has nowhere to go. Drilling a fixing puts a hole straight through it, and while a plug and some sealant will usually be fine, it is a hole in the thing that stops water reaching the wall.
Adhesive mounting avoids the question entirely. It also means you can fit shower storage in a rented flat without asking anyone, and in a newly tiled bathroom without wincing.
Getting the adhesive to actually hold
The 18 kg rating is real, but it assumes the pad has bonded properly, and that is entirely down to the surface. Three things matter:
Clean. Shower tile carries a film of soap and conditioner residue that you cannot see. Wipe the area with something that cuts grease, then rinse and dry it. Skipping this is the single most common reason a mount comes away.
Dry. The pad needs a dry surface. Fit it before a shower, not after.
Flat. Position each mount so the pad sits on the face of a tile rather than bridging a grout line. Grout sits slightly lower than the tile and is faintly porous, so a pad spanning it only makes partial contact.
Then leave it. Twenty four hours before you load the shelves feels like a long time when the box is open, but the bond keeps developing during it, and this is the difference between a shelf that holds full bottles for years and one that slides down the wall in a fortnight.
Where to put the five pieces
The set is five pieces because shower storage works better spread out than stacked.
Put the two shelves at roughly chest height, spaced so a tall bottle on the lower one clears the upper. Stand your tallest bottle against the wall and mark from there, because the bottle you own is a better guide than a tape measure.
The soap holders belong lower, at the height you actually wash at. The toothbrush holder does not have to live in the shower at all; if the cubicle is tight, it works just as well beside the sink.
Looking after stainless steel
SUS 304 is the grade used for kitchen sinks, so it copes with constant water without rusting. What does mark it is what you leave on it: shampoo residue dries to a film, and hard water leaves limescale.
A wipe with a damp cloth and mild soap handles both. Avoid abrasive pads and bleach based cleaners, which dull the finish without cleaning it any better.