Pre-ticked for trenches, confined spaces, gas and contaminated atmospheres, with three rows written. Plumbing is the trade that spends most of its time inside somebody else’s building, so most of its hazards were installed before you arrived.
The 1.5 metre figure is the SWMS trigger, not the shoring figure
A shaft or trench deeper than 1.5 metres is high risk construction work, so it needs a SWMS. That figure is about when the document is required. It is not the depth at which ground support becomes necessary, and treating it as though it were is the misreading that gets people buried.
Ground collapses at whatever depth the ground decides. Wet made ground, a trench beside an existing foundation or a run that was open through a weekend of rain can fail well under a metre and a half. The support decision comes from the ground conditions and the competent person, and the 1.5 is a paperwork line that happens to sit nearby.
A live sewer is a confined space with a schedule
Hydrogen sulphide is heavier than air, so it sits in the bottom of the chamber where you are working, and at the concentrations that matter it stops smelling before it stops being dangerous. That is the specific trap: people rely on the smell as a warning and it disappears exactly when it should be loudest.
Entry is on a permit, with continuous monitoring rather than a single reading, forced ventilation and a retrieval line. The rescue plan must not depend on the attendant going in. Most confined space fatalities are multiple, and the second person was almost always trying to help the first.
What was in the wall before you chased it
Asbestos turns up where plumbing goes. Pipe lagging, flue and vent runs, the back of a bath panel, boiler flash pads, textured coating on the wall you are about to chase, and the rope seal on an old flue. The limb is disturbance or work likely to disturb it, so it applies from the moment your job involves opening something up.
This is the practical difference between new build and refurbishment work for a plumber. On a new build you know what is behind the plasterboard because you put it there. On a refurbishment the honest answer before you open it is that nobody knows, and the register is the only thing standing between you and finding out with a grinder.
Brazing in an occupied building is hot works
Soldering and brazing pipework counts as hot works, and in an occupied or partly occupied building that brings a permit, a fire watch and a check of what is on the other side of the wall you are heating.
The other side of the wall is the part that gets skipped. Timber studs, dust in a void, a run of insulation or an old lath and plaster ceiling will take heat through a copper pipe and hold it, and the fire starts well after you have packed up. A fire watch of at least sixty minutes after the last flame, and a look into the void rather than at the wall, are what stop that.
Press fittings remove the hazard rather than managing it, which is why they are worth raising at the pricing stage rather than treating the flame as fixed.
One more reason to raise it early: an occupied building often has a hot works permit regime run by the client rather than by the principal contractor, with its own hours, its own sign-off and sometimes a flat refusal after a certain time of day. Finding that out on the morning you planned to braze twenty joints costs a day.
Common questions
Does a SWMS cover the whole plumbing package or one activity?
One activity, and the below-ground work is almost always a separate statement from the internal first fix. They carry entirely different hazards, need different controls and often happen months apart. A single statement covering both gets sent back, and rightly, because nobody on site can follow it.
Is a trench under 1.5 metres outside the rules?
Outside the SWMS trigger, not outside the duty. Below that depth the ordinary reasonably practicable duty still applies in full, which means the ground still has to be assessed, the edges still have to be protected and the services still have to be located. What changes is which document you are holding, not what you have to do.
Do I need a gas permit as well?
For work on or near pressurised gas mains or piping, isolation and purging come first and the supplier is involved where the service is not yours to isolate. That is a separate process from the SWMS: the statement says how the work is done safely, and the purge certificate is the evidence that a specific line was made safe on a specific day.
What about the water itself, is that a drowning risk?
The drowning limb is about work in or near water or another liquid with a risk of drowning, so it is aimed at rivers, tanks and flooded excavations rather than at a bathroom. Where it does apply to plumbing is pump stations, wet wells and any chamber that can fill faster than somebody can climb out, and those are the ones worth checking rather than assuming.
Can I reuse the same SWMS on the next job?
As a starting point, and not as it stands. The sequence of a drainage run survives from job to job; the ground, the services, the depth and who else is on site do not. A reviewer scanning for a generic document looks at the site name first and the ground description second, and those are exactly the two things a copied statement gets wrong.