Solar panels on concrete and clay tile roofs in New Zealand

Which tiles do you have?

“Tile roof” covers three quite different roofs in New Zealand, and each one changes how panels go on. Concrete tiles are the heavy, usually grey, charcoal or brown profiled tiles found on many brick-and-tile houses. Clay tiles, often called terracotta, are fired clay and usually orange-red. Pressed metal tiles are steel pressed into a tile shape, often with a stone-chip coating, and are sold under names such as Gerard and Decramastic.

If you are not sure, look at a broken edge or the underside of a tile in the roof space, or ask a roofer. A quote should name the tile type it has allowed for. If it just says “tile roof”, ask.

Pressed metal tiles are covered by the New Zealand Metal Roofing Manufacturers code of practice, which classes them as restricted-access cladding: people should walk only in the pan of each tile, where the batten supports it, in flat soft-soled shoes. Gerard sells its own solar brackets that fit under its tiles and fasten through the battens to the rafters, leaving no holes in the roof, for wind zones up to and including Extra High. Its solar bracket flyer describes fitting them while the tiles are being laid, so on an existing roof ask whether tiles have to be lifted and relaid to fit them. For long-run and corrugated steel, our metal and Colorsteel roof guide covers the very different fixing method.

How panels are fixed to a concrete or clay tile roof

On long-run metal, the installer screws brackets through the roofing. On tiles, nothing should be screwed through a tile. The usual method is a stainless steel tile hook. The installer lifts or slides a tile out, screws the hook to the rafter underneath, and lays the tile above back over the hook so its arm comes out between two courses of tiles. Rails bolt to the hooks and the panels clamp to the rails, the same as on any roof. Clenergy, one of the large mounting makers, sells hooks for most tiled roofs and extenders for high-profile tiles such as Spanish tiles.

The tile above the hook keeps the roof dry

A tile hook does not pierce the tiles, so the water still runs over them as normal. That only works if every lifted tile goes back down flat. A tile that rocks on the hook can crack or let wind-driven rain past.

To make the tile above sit flat, installers often grind a shallow notch in its underside where it crosses the hook. The alternative some installers offer is replacing the tile at each hook with a flashed metal or composite replacement piece. Either can work. What matters is that you know which one is planned, and that the quote includes it.

The rails and panels also need room to breathe. BRANZ says panel frames must meet wind and seismic loading requirements, be isolated so different metals do not corrode each other, and leave about 100 mm behind crystalline silicon panels for cooling airflow. Its photovoltaic systems guidance covers the basics.

Cracked tiles and leaks: where tile roof jobs go wrong

Consumer NZ’s tile roof guide says tiles can be damaged by weather or by people walking on the roof, that tiles become more brittle as they age, and that anyone working on a tile roof should use planks or a roof ladder. It also warns that older tile roofs may have no underlay, so water that gets past a tile can go straight into the roof space.

An installation means people on the roof for a day or more, carrying panels and rails. Some cracked tiles are a normal risk on an older roof. The problem is a cracked tile nobody notices, hidden under the array, letting water in for years. Set the expectations before work starts:

• Ask the installer to note any tiles that are already cracked, chipped or slipping, with photos, before anyone walks on the roof.
• Agree who supplies spare tiles and who pays to replace tiles broken during the job. Some tile profiles are no longer made, so ask now rather than after a tile breaks.
• Ask for photos of the finished array area, including the tile courses around each hook, before the scaffolding comes down.
• Check the ceiling below the array and the roof space after the first heavy rain.

Should you replace a tile roof before adding solar?

EECA’s guide to planning a home solar system sorts roof condition into three bands: ideal is a new or recently rejuvenated roof, good is one that will not need replacement or major maintenance within 10 years, and poor is one that will. EECA says a poor rating does not rule solar out, but on a tile roof the cost of getting it wrong is high: taking panels off, re-roofing and putting them back on is a second installation.

Signs that a tile roof is due for work, from Consumer NZ’s guide, include cracked or broken tiles, loose mortar under the ridge and hip tiles, slipped or missing tiles, and moss, which holds moisture against the roof. A tile roof with no underlay is another reason to get a roofer’s opinion. If the roofer suggests re-bedding the ridges or replacing a run of tiles, do it before the panels go on, while the whole roof is easy to reach.

If a re-roof is likely, ask for two prices: solar on the current roof, and solar fitted straight after a new roof. Solar on new long-run steel is a simpler, faster job, and the solar cost guide shows what a typical system costs once the roof is out of the equation.

Canterbury: heavy roofs after the earthquakes

Canterbury has a particular reason to think about tile roofs. In its guidance on lighter cladding for TC3 repairs and rebuilds, Building Performance says homes with lighter cladding and roofing generally performed reasonably well in the Canterbury earthquakes, that lighter claddings reduce the load on a home’s foundations, and that owners repairing or rebuilding on TC3 land should consider replacing heavy wall and roof claddings with lighter ones. It asks for roof cladding of no more than 20 kg/m². Monier’s technical statement for its Georgian concrete tile gives 53 kg/m².

That guidance is aimed at TC3 repairs and rebuilds, not at every tile roof. But if your house still has a heavy tile roof and a move to a lightweight roof is already on your list, solar is a good moment to make the decision. BRANZ’s Build magazine notes that swapping a heavy tile roof for a light one should be structurally straightforward, because the framing was built for the heavier load, but that wind uplift then becomes the main concern and the roof-to-wall connections need checking against NZS 3604.

If you keep the tiles, the framing is already built to carry a heavy roof. What matters more is how the array is attached: panels and rails push down and, in wind, pull up at each hook rather than spreading their load across the roof, so the installer has to fix every hook into sound framing. Ask what they checked in the roof space. Our Christchurch roof suitability guide covers shade, roof direction and usable space, which matter just as much on tiles.

Consent, wind and weight

Building Performance’s guidance on exempt building work (updated 22 October 2025) lists two exemptions for roof-mounted solar. Exemption 28D covers arrays of less than 40 m² and needs no authorised professional. Exemption 48A covers arrays over 40 m², or sites where the design wind speed exceeds 44 metres per second, and legally requires an authorised professional. The guidance names roofers, electricians and Chartered Professional Engineers as people who can advise. Both come with detailed conditions, so ask the installer which one your system falls under.

For scale, with panels of about 2 m² each, 40 m² is roughly 20 panels. A tile roof does not change the exemption, but it does mean the installer has to show that the hooks, their spacing and the framing they screw into suit your wind zone. On an exposed site or a large array, ask who has checked that.

What a tile roof adds to a solar quote

Expect a tile roof quote to be higher than the same system on long-run metal, because the job takes longer and needs different parts. We have not seen a published New Zealand figure for the difference, so compare itemised quotes rather than relying on a rule of thumb. The extra cost usually comes from:

• Tile hooks or replacement flashing pieces in place of standard metal-roof brackets.
• Labour to lift, notch and relay tiles at every hook, and to move around the roof without cracking tiles.
• Spare tiles and the time to replace broken ones.
• Scaffolding or edge protection. WorkSafe’s good practice guidelines for working on roofs say perimeter or edge protection should be installed on exposed roof edges where there is a risk of falling.
• Any roof repairs agreed beforehand, such as re-bedding ridge tiles.

A much cheaper tile roof quote is worth questioning, not celebrating. Ask what it leaves out. Our guide to common solar quote mistakes covers other gaps to look for.

Eight things to get in writing

The connection side is separate from the roof. Your lines company still has to approve the system and its export limit: see our guides for Orion, MainPower, EA Networks and Alpine Energy. EECA’s quotes and installation guide covers the rest of the quote.