How to build a slab for shed and outdoor shower?

amichaelmedia

planning for a slab for shed/outdoor shower between my garage wall and neighbors 

I plan on having a hot cold shower coming off my garage wall, hidden by merbau screen. 

And to have a 1.7m x 2.1m Gable shed behind it, square to the fence. 

I plan to concrete in the drainage for the shower and to install drainage across the fenceline that will be connected to a down pipe on the other side of the fence. 

The area is 2.1m x 5m

  

Seeking advice for:

- protection of my slab

- protection of neighbors slab 

MitchellMc

Hi @amichaelmedia,

If the main concern with protecting both slabs is water, then the important factor is ensuring the shower area is correctly graded to a drain so all water is fully captured and directed away. You want to avoid any situation where water can escape the shower zone and sit against either slab, as that would create ongoing moisture issues and would also be unlikely to comply with current plumbing regulations. Because this is a hot-and-cold shower, it falls under the requirements for a wet area, which makes it very different from a simple cold-water outdoor rinse shower that can sometimes discharge to the ground. In this case, the drainage will need to be properly connected, typically to a sewer, and installed by a licensed plumber, so this is not really a DIY component.

Given the proximity to your neighbour’s slab, it is especially important that everything is done by the book. If your neighbour has any concerns, having a compliant design and certified plumbing will protect you. It would also be wise to have a quick discussion with your local council to confirm any requirements around outdoor showers, drainage connections and setbacks, as this can vary. From a slab protection point of view, the height and finished level of the new slab is also important. You will likely need to excavate enough to build the slab so it does not end up higher than the bottom course of the existing brickwork, helping prevent moisture bridging. A builder can give you clear advice on this aspect.

Overall, what you are proposing is achievable, but there are several moving parts that need to be considered together. Engaging a plumber early and having a chat with the council and possibly a builder will help ensure the shower and slab are compliant, well-drained, and do not cause any damage to your slab or your neighbour’s over time.

Please let me know if you have any questions.

Mitchell