I have just moved into a new place and the walk in shower has a great, but flat, pocket shelf cut into the back wall. However the water pools after every shower which requires me to pick up all the bottles and wipe it down. Very annoying. What would be the best way to stop this? Can you put in a gradient to the base of it easily? Any ideas would be very gratefully received!
Short of taking the shelf up (which might not be possible depending on the relationship of the shelf to the wall stone, and will probably be difficult in any case) you are going to need to cut channels into the surface, as it has been (improperly, by my lights) installed flat, rather than properly sloped to drain.
If you can get the shelf out intact (or not intact, and you get a replacement) you can shape the mortar bed to let the shelf self-drain without surface cuts.
Fortunately marble is pretty easy to cut channels into, as stone or tile goes. Granite or porcelain tile would be a lot more difficult to modify in this way. Make sure that the channels are angled to drain (deep on the shower side, shallow towards the rear.)
- Proper: remove and reassemble the shelf. Might be difficult, costly and even uneconomical. I see lots of silicone, you can scrap it off to see how it's mounted under the silicone. Silicone is easy to replace. If there is nothing under it, maybe the shelf will come out easily with few blows with a wooden hammer to the edge.
- ad-hoc but permanent: sand the shelf, more at the front. The amount of dust might make cleaning more costly than the proper option, shelf will end up warped.
- temporary: buy a plastic shelf, hang it about 5cm above the shelf. You'll put your stuff on the plastic shelf and the 5cm gap will make it trivial to wipe the marble one.
The shelf as it is, is an error by whoever built it. The best would be to make that person fix it, but I suspect you'd try it if you could.