Which kind of spouting leak have you got?
| Probable cause | Usual fix | |
|---|---|---|
| Steady drip from one spot, under a join or corner | A perished rubber seal on PVC spouting, or failed sealant and rivets on metal | The join cleaned and resealed, or a new joiner fitted |
| Drips along a stretch, with rust stains on the path below | Rust holes in the base of metal spouting | That length replaced, or the whole run if the rust is widespread |
| Water pouring over the front in heavy rain | A blockage, too few downpipes, or spouting too small for the roof area | Cleared first, then an extra downpipe or bigger spouting if it still overflows |
| Water running down the fascia or wall behind the spouting | Overflow escaping backwards, or roofing that stops short of the spouting | The spouting re-set, or the roof edge extended with a flashing |
| Puddles still sitting in the spouting days after rain | Not enough fall, or brackets that have sagged or snapped | The run re-hung on new brackets with a proper fall to the outlet |
| A downpipe leaking at a joint or gushing near the ground | A blockage lower down, often where it meets the stormwater drain, or a cracked joint | Blockage cleared, joint resealed, or a drainlayer called in for the drain |
Why spouting gives up early
Seals and sun. PVC spouting relies on rubber seals or glued joins at every joiner and corner. Years of sun stiffen the seals and make plastic brackets brittle, so drips tend to show at the joins first.
Cut edges and mixed metals. In BRANZ trials in Rotorua's geothermal air, the aluminium-zinc coated steel widely used in New Zealand for roofing, spouting and downpipes showed only small rust spots after 2 years, but heavy rusting near unprotected cut edges. New Zealand Steel says copper isn't compatible with ZINCALUME, galvanised steel or COLORSTEEL, especially where water runs off copper onto them, and that stainless steel fasteners and lead don't belong with ZINCALUME either. Its rule of thumb is that water can run from zinc onto copper, but not from copper onto zinc. If a mix of trades and metals has been on your roof over the years, tell the roofer.
Salt where the rain doesn't reach. The metal roofing industry's Code of Practice says parts of a building that rain rarely washes, like overhangs and unlined soffits, collect salt and dust and corrode faster. BRANZ testing on an Auckland building near the harbour found sheltered spots collected about 3 to 8 times more salt than exposed ones. New Zealand Steel's maintenance guide for ZINCALUME says gutters, downpipes and fascia need washing by hand every 3 months, because rain alone doesn't keep them clean.
Water that sits. Spouting without enough fall holds puddles and leaf sludge, and the base goes first. Dimond recommends a minimum fall of 1:500 and says ponding that doesn't drain or dry within hours may affect the material warranty.
Roofing that stops short. NZMRM and Dimond set minimum overhangs for roof sheeting into the spouting, 50 mm on most pitches, to stop water blowing back. Where the roofing stops short, water runs down behind the spouting and looks like a spouting leak.
Stone chips. Pressed metal tiles with a textured chip finish can shed granules over time, and BRANZ lists clearing them out of the spouting as part of normal maintenance.
Snow. In snow-prone areas it's normal to fit snow straps to spouting, and the Code says gutters, flashings and chimneys need extra fixings to resist sliding snow. Spouting bent or pulled loose after a snowfall usually needs re-hanging, not sealing.
Ladders, power lines and old spouting
A ladder is for looking, not leaning out to work. WorkSafe says New Zealand has no minimum height for fall risk and recommends managing any possible fall of more than 1 metre with barriers or restraint, which is why we'd leave the repair itself to a roofer. If you do take a look, use firm, level ground on a single-storey house with someone holding the ladder, keep well away from the power line to the house, and never step off onto the roof. In a home built before 2000, spouting and downpipes could be asbestos cement, so don't cut, drill, scrape or water-blast them.
Diagnose it from the ground
Wait for steady rain
Walk round the house with an umbrella or watch from the windows. Note every spot where water drips, sheets over the front or runs down the wall.
Mark each drip
A bit of chalk on the path under each one makes it easy to show the roofer later, when it's dry and nothing is dripping.
Check each downpipe at the bottom
If one is dry or barely trickling while the spouting above overflows, it's blocked. Clear it yourself only when the outlet sits at ground level and comes free by hand.
Look at the fascia and soffit after rain
Dark streaks, bubbling paint or soft timber behind the spouting mean water has been getting in behind it for a while. Our page on fascia and barge boards covers that repair.
Have a look on a dry day, if you're comfortable
On a single-storey house, a ladder look can show standing water, rust holes, sagging brackets and split joins. Photograph rather than poke.
Send the photos and chalk marks to a roofer
They'll usually know quickly whether it's a reseal, a re-hang or new spouting.
Blocked spouting and your insurance
This one catches people out. The Insurance Council says insurers don't treat blocked gutters that overflow and damage walls as sudden, so that damage generally isn't covered.
In one of its examples, an insurer declined a claim for water damage and rot caused by gutters blocked with leaves for years. A regular clean, more often under trees, is a small job by comparison. Our gutter cleaning page covers what's involved.
What makes a spouting job bigger or smaller?
The main things are whether it's a repair or a new run, the spouting material, how many metres are involved, and whether a two-storey house needs scaffolding. A reseal or a new joiner is a short visit. A new run also means new downpipes, brackets and any fascia repairs found along the way.
A good written quote names the spouting material and profile, the number of downpipes, how the old spouting will be disposed of, and what happens if rotten fascia turns up. Our spouting repairs page covers the smaller jobs.
Your part, and the roofer's
You can
- Watching where it leaks in steady rain
- Clearing a downpipe outlet at ground level
- A ladder look on a single-storey house, if you're comfortable
- Trimming branches you can reach from the ground
- Hosing salt off the underside of spouting near the coast, from the ground
Leave to a roofer
- Resealing joins or fitting new joiners
- Replacing rusted lengths or whole runs
- Re-hanging spouting to fix the fall
- Adding downpipes, overflows or snow straps
- Anything that might be asbestos cement
What we'd do with leaking spouting
If it's a single join dripping, we'd get it resealed and not overthink it. If rust has broken through in more than one place on old metal spouting, we'd stop patching and get a price for a new run, because the metal around a rust hole is usually thin as well. Clean spouting that still overflows we'd treat as a capacity problem, and we'd ask about adding a downpipe before anything else.
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.