PLUMBING GUIDE 2008

Shower cubicle

If you would like to install a separate shower unit without the need for doubling
it up with the bath, there are several design considerations to make regarding
its location and construction.

Shower unit

A complete shower unit may be purchased which includes all the necessary
components. The shower, shower tray and walls of the cubicle are all pre-
made and require only assembly and installation. Obviously, this set up is also
relatively expensive.

Shower cubicle

Or, build in a cubicle making use of the walls of the room and/or additional
stud walls constructed to suit. This method is more labour intensive but can
represent a considerable cost saving. It also has the advantage that it may be
built to suit your requirements more exactly.

The possibilities are quite varied. The shower may be built against one wall
and stud walls constructed on one or two of the sides. The shower could
make use of the corner walls of the room. There is also the option of building
a shower as an integral part of a cupboard arrangement. The ‘open’ side or
sides may then have a screen or curtain installed. Access to the shower may
be from one side or the corner of two sides.

Shower unit plumbing

Consideration at the design stage should also be given to the plumbing. It
always looks far neater and professional if all the pipework is hidden from
view. This can be achieved either by routing the pipes through the rear wall of
the shower if this is possible, or by building a false wall in front of all the
pipework.

PLUMBING GUIDE 2008

Shower unit drainage and waste

Drainage from the shower tray can be a little problematical as the need for a
‘fall’ in the waste pipe can be difficult to achieve. The fact that the base of the
shower is at floor level means that the waste will need to drop below it. If the
joists supporting the floor run in the same direction as the waste pipe, there
may be room to fit the waste within the floor depth. However, you’ve probably
just discovered that yours run the other way. The way round this is to raise the
base of the shower to provide the necessary slope of 6mm per 300mm length
of waste pipe. A quick calculation will show you that the additional height of
the base will not present too much of a problem. (a 3m run of waste will
require the base to be lifted by 60mm). Some of the "top of the range" shower
trays come with an adjustable base height.

The tray is fitted with a shallow trap to minimise the under tray space
requirements, but not if the waste is connected directly to the main stack via a
strap boss. In this case it is required to be a deep trap.

Shower cubicle walls

Stud walls may be constructed to suit your design. The face of the walls
should be made of marine grade plywood since the area will be subjected to
considerable moisture. This is screwed and glued to a frame of suitably
spaced and strengthened timber studwork.

Remember to seal all the angles between walls and the edges of the shower
tray with mastic, so that there is no possibility of water percolating through.

The false wall referred to earlier is built on the same principles. It will
accommodate the pipework between the timber uprights and also provide
support for fixing the shower controls and adjustable rail for the shower head.

The surface of these walls should be sealed and may then be clad with
ceramic tiles using a waterproof adhesive.