Advice on trench depth for SWA - Answered!

I've just seen a video on youtube where an electrician ran SWA across a garden path by cutting a channel in it. Surely that's not allowed?

The regulations often really aren't as simple as something ‘is allowed’ or ‘is not allowed’. There has been a definite trend over more recent years to move away from a rigid list of things to do and avoid, and more towards what needs to be achieved - leaving the designer with much more scope to so what's sensible in any particular situation.

In a way that's illustrated by the very title of the wirings regs. Back in the 1st Ed the wiring regs were called “Rules and Regulations” - and the Victorians had very specific ideas about the differenence between a Rule and a Regulation - a Rule demanded or prohibited (i.e. was a ‘thou shalt’ or ‘thou shalt not’) whereas a Regulation merely put conditions on things ( ‘xyz may be done on any day excepting the Sabbath’).  By the 8th Ed the word “Rules” had disappeared forever from the title.

There might even be situations - perhaps when running a cable over a bridge or some layered foundations - that cutting a shallow trench in the thin non-structural surface layers is a far better idea than going deeper. A simple set of rules really can't cover every situation.

   - Andy.

I've just seen a video on youtube where an electrician ran SWA across a garden path by cutting a channel in it. Surely that's not allowed?

The regulations often really aren't as simple as something ‘is allowed’ or ‘is not allowed’. There has been a definite trend over more recent years to move away from a rigid list of things to do and avoid, and more towards what needs to be achieved - leaving the designer with much more scope to so what's sensible in any particular situation.

In a way that's illustrated by the very title of the wirings regs. Back in the 1st Ed the wiring regs were called “Rules and Regulations” - and the Victorians had very specific ideas about the differenence between a Rule and a Regulation - a Rule demanded or prohibited (i.e. was a ‘thou shalt’ or ‘thou shalt not’) whereas a Regulation merely put conditions on things ( ‘xyz may be done on any day excepting the Sabbath’).  By the 8th Ed the word “Rules” had disappeared forever from the title.

There might even be situations - perhaps when running a cable over a bridge or some layered foundations - that cutting a shallow trench in the thin non-structural surface layers is a far better idea than going deeper. A simple set of rules really can't cover every situation.

   - Andy.