How do you know your spouting needs work?
Watch it in steady rain. Water sheeting over the front, a drip from one spot under a join, or water running down the wall behind are the things to look for. On a dry day, rust streaks on the path or a run that dips between brackets tell the same story.
Most of that is repair work, covered on our spouting repairs page. New spouting makes sense when rust has broken through in several places, brackets are letting go along a whole wall, or the fascia behind has gone soft.
The legal bar is low. The NZMRM Code of Practice notes Building Code clause B2 asks external gutters to last just five years, because they're easy to replace. The product and the workmanship are what you're really relying on.
PVC or pre-painted steel?
| PVC (uPVC) | Pre-painted steel | |
|---|---|---|
| Rust | Marley says its uPVC spouting won't rust or corrode | Coated, so scratches and raw cut edges are the weak points |
| Guarantee or warranty | Marley: 15 years against defects in material and manufacture | COLORSTEEL MAXAM gutters, downpipes and fascia: 15 years against perforation, 10 on the paint, in NZ Steel's Mild to Very Severe categories |
| Joins | A joiner at each length and corner, where old PVC tends to drip | Made to length, so a wall needs fewer joins |
| Brackets | Marley: no more than 500mm apart, 300mm in high wind or snow areas | Roofing Industries: up to 750mm apart on gutters under 180mm wide |
| Painting later | Light colours and acrylic only, Marley says, or the plastic moves and leaks | Comes pre-finished. NZ Steel doesn't recommend touch-up paint on COLORSTEEL |
| Near the sea | No rust, but brackets and fixings still need to suit the site | Within 100 metres of salt water, NZ Steel asks you to contact it to confirm the warranty |
What about aluminium or copper?
Most homes don't need either, with two exceptions. In geothermal areas such as Rotorua, BRANZ found aluminium-zinc coated steel appears to corrode faster in strong geothermal air than by the sea, while aluminium and 304 stainless steel held up much better. And copper doesn't mix with coated steel: New Zealand Steel says it isn't compatible with ZINCALUME or COLORSTEEL, especially where water runs off the copper onto them.
Which profile suits your house?
Quarter round is the everyday Kiwi shape. Marley calls its Stormcloud quarter round New Zealand's most popular spouting style, and Dimond's Quad is the metal version.
Half round and box profiles include the heavy-rain options. Marley designed its Typhoon half round for high rainfall, and Dimond says its Box 125 suits heavy rain where fewer downpipes are wanted.
Period styles suit older homes. Roofing Industries says its Old Gothic is reminiscent of spouting on colonial homes.
Snow country needs more support. Dimond says snowfall areas need closer brackets and snow straps, and makes its Quad SI for South Island conditions.
What replacing spouting involves
The old spouting comes off first, which is the moment to check the fascia. Soft timber gets repaired before anything goes up, or the new brackets have nothing to grip.
Brackets go on at the maker's spacing, set to a fall towards the outlets. Dimond and Roofing Industries give 1:500 as the minimum, and Roofing Industries recommends 1:200 for better self-cleaning. Dimond says an overflow outlet at least the size of the main outlet should always be provided, so a blocked outlet spills somewhere harmless.
The roofer should also check the roofing reaches far enough into the spouting. NZMRM and Dimond set minimum overhangs, 50 mm on most pitches, to stop rain blowing back behind it. On a two-storey house, expect scaffolding or edge protection in the quote, which WorkSafe strongly prefers to harnesses for roofing work on homes.
Does new spouting need a building consent?
Usually not. Schedule 1 of the Building Act allows repairs, and replacement with a comparable product in the same position, without consent, though the work must still meet the Building Code. If you're moving downpipes or changing the stormwater connection, check with your council or ask the roofer first.
What a good spouting quote spells out
- The material, brand and profile by name. NZ Steel suggests having COLORSTEEL named in the quote, since genuine COLORSTEEL has the brand printed on the reverse
- How many downpipes and outlets, and where the overflow goes
- Bracket spacing and the fall they'll set
- Disposal of the old spouting, and the plan if it's asbestos cement
- How fascia repairs found along the way get agreed before work carries on
- Scaffolding or edge protection above a single storey
- Whether it's a quote (a firm figure) or an estimate (a best guess)
- The warranty and its washing schedule. After residential building work, the contractor must give you warranty and maintenance details in writing
What you can check, and what's for a roofer
You can
- Watching it in heavy rain and noting where it spills
- Checking each downpipe outlet at ground level runs freely
- Looking for rust streaks or stained fascia from the ground
- Hosing salt off the underside of metal spouting from the ground, near the coast
Leave to a roofer
- Any work at spouting height
- Resealing joins and replacing brackets
- New spouting, downpipes and overflows
- Old spouting that might be asbestos cement, which WorkSafe says can turn up in homes built before 2000
What we'd do if it were our spouting
If it only overflows, we'd get it cleared and watch it through the next heavy rain before replacing anything. If rust has come through in more than one place, we'd replace the run rather than patch it, and have the fascia checked while it's off. We'd want the brand, profile and downpipe count in writing either way. When you're ready, tell us what's happening and we'll pass it to one checked local roofer.
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.