What does a roof plumber do?
Think of a roof in two parts. The covering, tiles or sheets, keeps the rain off. The plumbing carries it away: gutters and downpipes, box gutters and valleys, and the flashings (folded metal strips) that seal the joins around chimneys, skylights, vents and walls.
Roof plumbers do the second part, and many also install and repair metal roofs, because a metal roof is mostly sheets, flashings and gutters working together. Broken tiles and ridge mortar are a roofer's job.
In Victoria the legal name is roofing (stormwater) work. It covers metal roof coverings, flashings and the whole roof drainage system, right through to connecting downpipes to a below-ground stormwater drain or a tank. Tiled, slate, timber and concrete roof coverings sit outside it, and so does plain cleaning or painting of gutters.
Signs you need a roof plumber
Ceiling stains near a chimney, skylight or where the roof meets a wall usually point to flashing. Gutters that overflow, drip at the joins or rust through are roof plumbing, and so is any leak along a box gutter.
On metal roofs, look for rust around screws and laps, lifting sheet edges and old lead flashings, which BlueScope says aren't compatible with Colorbond or Zincalume steel. Our guide to metal roof leaks covers the usual culprits.
How a roof plumber tracks down and fixes the problem
Find the water's path
A good roof plumber checks the roof space as well as the roof, then runs a hose over one section at a time to see exactly where water gets in.
Fix the flashing, not just the stain
BlueScope says skylights and chimneys often need specialist flashing, and that on low-pitched metal roofs anything blocking the sheet channels needs a small gutter above it. Silicone over an old flashing rarely lasts.
Check gutters and valleys against the rules
The NCC (the national building code) only allows valley gutters on roofs pitched more than 12.5 degrees, with at least 15 mm of freeboard (the gap above the waterline). Gutters need a set fall, enough downpipes and a way for overflow to escape.
Match the metals
New steel shouldn't sit against lead or copper. And if the roof feeds a drinking water tank, the NCC says gutters, downpipes and flashings must not contain lead.
Who's allowed to do roof plumbing?
| What counts as roof plumbing | Who can do it | |
|---|---|---|
| Victoria | Metal roof coverings, flashings, gutters, downpipes and the connection to a below-ground drain or tank | A plumber licensed or registered for that class of work. Jobs of $750 or more need a compliance certificate |
| New South Wales | Gutters, downpipes, flashings and metal roof coverings, including skylights and ventilators | A roof plumbing contractor licence for jobs over $5,000 including GST |
| Queensland | Covered by QBCC licence classes such as roof and wall cladding, and metal fascias and gutters | A licence in the right class. Check current thresholds with the QBCC |
| Tasmania | Roof plumbing is one stream of the standard plumbing licence | Licensed plumbers only since 2010, with a limited endorsement for builders on their own jobs |
Roof plumber, roofer or plumber?
Call a roof plumber for gutters, downpipes, box gutters, valleys, flashings and metal roofs, a roofer for tiles and ridge capping, and a general plumber for blocked drains. Many businesses cover more than one.
Other states handle licensing differently, so ask which licence covers your job and check it on the state register. In Victoria, that's the Building and Plumbing Commission's Practitioner Search, and plumbers carry a BPC identification card you can ask to see. Our licence guide covers every state.
What a roof plumbing quote should include
- The licence or registration number, and what class of work it covers
- Exactly what's being replaced: metres of gutter, which flashings, which sheets
- Materials by brand and finish, and that they're compatible with your roof
- How the leak was found, and how the fix will be tested
- Workmanship warranty, and whether prices include GST
What you can check, and what needs a roof plumber
You can
- Hose out single-storey gutters from a ladder and watch for drips and pooling
- Mark ceiling stains and note which rain, wind direction or time of year sets them off
- Look over flashings and gutters from the ground with binoculars, and take photos
Leave to a roofer
- Anything that means standing on the roof
- Replacing or resealing flashings around chimneys, skylights and walls
- Box gutters, valleys and metal roof sheeting
- Separating or replacing lead flashings on a steel roof
Who we'd call
If the problem is water moving across or off the roof, through gutters, flashings, valleys, box gutters or a metal roof, we'd call a roof plumber first. If it's cracked tiles or crumbling ridge mortar, a roofer. Either way, we'd check the licence before agreeing to anything, and ask them to find the leak with a hose test before quoting the fix.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.