The Australian plumber who installed the shower in my wet room
presumably believed that, because water flows down a plughole in an
anticlockwise direction in the southern hemisphere - the opposite to
ours - that it also flowed uphill in the north (just kidding), with the
result that the shower drain is higher than the surrounding floor, with
the inevitable consequences.

As wheelchair access is needed, nothing permanent can be added to
prevent this, so I made a sand filled bicycle innertube *sausage* to
try to overcome the problem but, as the floor is a dimpled, non slip
surface, it didn't do the job adequately.

Anyone got any suggestions for improvement? The impervious rubber outer
of the tube is, I suspect, key, but I can think of nothing, non rotting
and non smelling, that will cover the tube, expand, and fill those
gaps.

Tony.