Do you need a gutter guard at all?
For a lot of homes, no. Regular cleaning and trimming back overhanging trees does the job, and it's what the spouting makers prefer. Their concern is that a permanent guard hides what's happening underneath: fine particles still collect on the base of the spouting, and wet debris trapped against the metal and the ends of the roof sheets speeds up corrosion.
Metal spouting also needs washing, not just clearing. New Zealand Steel's maintenance guide for ZINCALUME says roofing relies on rain to wash it, but gutters, downpipes and fascia need washing by hand every 3 months. A guard that's screwed down makes that harder.
Where a guard does make sense is under big trees, pines or anything that drops more than a yearly clean can keep up with, or on a two-storey house where every clean means scaffolding or a roofer at the edge. In those cases, choose one that comes off, and keep the cleaning schedule anyway.
If you fit one, which suits which house?
| What we'd look at | Why | |
|---|---|---|
| Corrugated iron roof | Mesh with a trim shaped to the corrugations | A flat edge leaves a gap at every rib for leaves, birds and wind-blown rain |
| Trapezoidal longrun | Mesh trimmed to the rib profile, or fitted with matching closures | The deeper ribs leave bigger gaps if the edge isn't closed off |
| Concrete tiles | Full-cover mesh tucked under the bottom row of tiles | The edge tiles have to be lifted and re-set properly, which is a roofer's job |
| Decramastic tiles | Mesh fitted by someone who knows how to work around these tiles | They dent and crack underfoot, and a careless install causes the next leak |
| Flat Butynol roof with outlets | Outlet guards or leaf domes rather than mesh along an edge | On a flat roof a blocked outlet means ponding, so the outlet is what needs protecting |
| Within 500 m of the coast | Mesh and fixings that suit the exposure zone, confirmed by the installer | Salt builds up fastest where rain doesn't wash, and some metal pairings corrode |
| Rotorua or another geothermal area | Ask about aluminium or stainless mesh, and steer clear of copper | BRANZ found aluminium and 304 stainless held up in Rotorua's geothermal air, while copper corroded heavily |
| Rainwater tank supply | Finer mesh, plus a leaf diverter or first-flush device at the downpipe | Less debris rotting in the spouting and washing toward the tank |
| Light leaf fall, single storey | Probably no guard, just a regular clean | There's little to stop, and the spouting stays easy to wash |
| Old fibrolite or asbestos cement roof | Nothing until it's been tested | WorkSafe lists cement roof sheeting, spouting and downpipes among the places asbestos turns up |
Mesh, brush or clip-on: what's the difference?
Full-cover mesh runs from the outer lip of the spouting up onto the roof, so leaves land on the mesh and blow or wash off. It does the most for homes under trees, and it's the type that needs the most care where it meets the roof. Ask for a system that can be unclipped so the spouting underneath can still be cleared and washed.
Brush and foam inserts sit inside the spouting. They're cheap, but they hold debris and moisture against the metal and have to be lifted out to clean.
Clip-on plastic covers are the usual DIY kit. They're fine for light leaf fall on an outbuilding, and less so under pines, where needles lodge in the coarse openings.
Downpipe filters and leaf diverters catch what gets past, and they matter most if your drinking water comes off the roof.
Check the spouting first, and what touches it
A guard over sagging, rusting or leaking spouting just hides the problem. Get the leaks, fall and brackets sorted first. Our guide to leaking spouting helps you spot what's wrong.
Then ask about metals. New Zealand Steel says stainless steel fasteners shouldn't be used with ZINCALUME in any environment, and the COLORSTEEL warranty excludes damage from wet contact with stainless steel or contact with other metals. Stainless mesh is widely sold, so ask the installer what your spouting is made of, how the mesh and fixings avoid a bad pairing, and whether any roofing or spouting warranty is affected. Get the answer in writing.
Near the coast, salt matters too. The metal roofing industry's Code of Practice says parts that rain rarely washes collect salt and corrode faster, and BRANZ found sheltered spots on an Auckland building near the harbour collected about 3 to 8 times more salt than exposed ones. A cover over the spouting makes it one of those sheltered spots, which is another reason to choose one you can lift off and wash under.
Fitting guards means working at the roof edge
WorkSafe recommends managing any possible fall of more than 1 metre with barriers or restraint, and says single-storey homes need the same fall protection as two-storey ones. Fitting full-cover mesh means leaning out over the spouting and working on the roof itself, so we'd leave it to an installer with the right gear. If the roof is old cement sheet, leave the spouting and the roof alone until they've been tested. WorkSafe says homes built before 2000 may contain asbestos, and you can't tell by looking.
Will guards mean no more spouting cleaning?
No. They cut down the big stuff, but fine debris, bits of moss and lichen and the odd seed still get through or sit on top. Monier, the tile maker, recommends cleaning gutters at least once a year, and checking the roof twice a year if it's tree-lined. Our gutter cleaning page covers what that involves, and moss and lichen explains what's growing on the roof.
It matters for insurance too. The Insurance Council says blocked gutters that overflow and damage walls aren't treated as sudden damage, so that damage generally isn't covered.
How to decide, in order
Look at what falls in, and how often
Note which trees overhang the roof, what they drop and when. Trimming them back often does more than any guard, and if a yearly clean then keeps the spouting clear, you may not need one at all.
Note the roof and spouting
Corrugated iron, longrun, decramastic, concrete tile or flat membrane, and PVC or metal spouting. If the roof is old cement sheet, test for asbestos first.
Check your exposure
Close to the sea, or in a geothermal area like Rotorua, the metal choice matters more. Ask the installer to confirm your exposure zone.
Fix the spouting
Repair or replace leaking, rusting or sagging runs before anything goes over them.
Get the specification in writing
The quote should name the mesh material and hole size, how it comes off for cleaning, the fixings, the trims for your roof profile, and whether a clean is included.
Questions to ask the installer
- What metal is the mesh, and what are the fixings made of?
- Can it be lifted off so the spouting can still be cleaned and washed?
- How will it meet my roof profile without leaving gaps at the ribs or tiles?
- Will you fix anything through the roofing, and how will those holes be sealed?
- Does it affect the warranty on my roof or spouting? Can you put that in writing?
- Is a spouting clean and a check of the brackets included?
What you can sort out, and what's for an installer
You can
- Noting which trees drop on the roof, and what they drop
- Finding out what your roof and spouting are made of
- Fitting a downpipe filter you can reach from the ground
- Keeping branches trimmed back, with an arborist for big trees
Leave to a roofer
- Fitting full-cover mesh and roof-profile trims
- Lifting and re-setting edge tiles
- Repairing or replacing spouting first
- Anything on or near an asbestos cement roof
What we'd do
We'd start with the trees and a cleaning routine, not a guard. Trim what overhangs, then get the spouting cleared and washed on a schedule. If it still fills faster than that, we'd fit full-cover metal mesh that unclips for cleaning, trimmed to the roof profile, with the metal and fixings named in the quote and the installer's word on any warranty in writing. Clip-on plastic is a shed solution in our book.
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.