What makes a Christchurch re-roof different
Heavy tiles and the quakes
BRANZ found the stronger shaking in the hill suburbs did substantial damage to heavy tile roofs, and the NHC says a single roof tile can weigh up to 4.5 kg. Going to longrun or metal tiles takes a lot of weight off the house. It's a change of roofing system, though, which brings in the consent question below.
Which era is your roof?
In BRANZ's sample, houses from 1960 to 1979 had 32 heavy tile roofs to 57 sheet roofs, and pre-1930 villas were almost all sheet. A villa going from old corrugated iron to new is often a straight swap. A 1960s tile roof going to steel isn't, because the battens or purlins usually change too.
Snow and wind loads
Building Code clause B1 says a roof must handle snow and wind loads over its life. The metal roofing code of practice adds that sites above set altitudes in the snow zones need specific design, and that spouting, flashings and chimneys need extra fixings where snow is common. With gusts recorded at 172.4 km/h, the fixing pattern matters on exposed hill sites.
Steel near the sea
Near the coast, the harbour or the estuary, ask which corrosion category your site falls in under the metal roofing code of practice, from A (mild) to F (extreme marine), and what the manufacturer allows there. In Zone D, PlaceMakers' summary of NZS 3604 says stainless fixings must not be used with galvanised steel.
Heritage streets and pre-1900 houses
Lyttelton, Inner City West and seven other Residential Heritage Areas were approved in September 2025, on top of the city's character areas. Ask the council whether your overlay limits roofing material or colour before you choose. For a house built before 1900, Heritage New Zealand says works that may modify the structure need an archaeological authority.
Does a Christchurch re-roof need a building consent?
Sometimes. Schedule 1 of the Building Act lets you replace parts of a building without consent if you use a comparable product in the same position. New Plymouth District Council gives replacing roofing more than 15 years old with the same type of roofing as a typical consent-free job.
Changing the system is less clear-cut. MBIE counts heavy clay tiles replaced by profiled metal in the same position as exempt work, but Wairoa District Council says going from corrugated iron to pressed metal tiles, or changing the purlins, needs consent, as does replacing cladding that failed within 15 years. We haven't found Christchurch City Council guidance on this in our sources, so ask the council before you sign. Consent or not, the work must meet the Building Code.
If it does need consent, the roofing is restricted building work. A suitably licensed LBP must do or supervise it: a Roofing LBP, a registered plumber, or for lightweight profiled metal, a Carpentry LBP. You tell the council who they are, they give you a record of work at the end, and you apply for a code compliance certificate. Our consent guide walks through it.
What makes a Christchurch re-roof bigger or smaller
Stripping heavy concrete tiles is slower and heavier work than lifting old iron, and a switch from tiles to steel usually means new battens or purlins. Expect scaffolding, since WorkSafe's example control for house roofing is scaffolding with full edge protection. A consent, coastal-grade materials and any asbestos removal all add to the job. Our COLORSTEEL and longrun profiles pages help with the material choice.
A written quote should spell out the product and profile, what happens to battens and purlins, new flashings and spouting, who applies for any consent, the scaffolding, asbestos testing, and how variations will be agreed.
If the contract is $30,000 or more including GST, it must be in writing, and the contractor must give you the official disclosure information and checklist before you sign. Check with your insurer before work starts too, since cover can change during renovations.
Rule out asbestos before the strip-off
Any home built before 2000 may contain asbestos, and WorkSafe lists asbestos cement roof sheets, ridge capping and Super Six panels among the usual places. You can't tell by looking. Removing more than 10 square metres of non-friable asbestos needs a Class B or Class A licensed removalist, followed by a clearance inspection. Don't let anyone water-blast, cut or walk on it first.
What to ask a Christchurch re-roofer
- Does this job need a building consent, and who's applying for it?
- Are you an LBP, in which class, and will I get a record of work?
- What exposure zone and corrosion category is my site, and what's the product rated for?
- Going from tiles to steel, what happens to the battens and purlins?
- Is scaffolding with edge protection in the price?
- Has the old roof been tested for asbestos, and who removes it if it's there?
- Can I see your disclosure statement and written contract before I sign?
Our take on Christchurch re-roofs
On a sound house with a worn-out concrete tile roof, we'd lean towards lighter longrun, especially on the hills, and budget for a consent rather than hope it isn't needed. We'd get the asbestos question answered before anyone prices the strip-off. And once it's done, we'd let the insurer know, because the Insurance Council says to update your sum insured after a new roof.
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.