Longrun is the steel roofing you see on most New Zealand homes, farm sheds and factories. Here’s what it is, how the profiles and steel differ, what it costs installed in the Waikato in 2026, and how it goes on.
Short answer: longrun roofing is steel roofing roll-formed into sheets that run the full length of the roof, from ridge to spouting, with no joins down the slope. It comes in two main profiles, corrugate and trapezoidal rib. On homes it’s usually pre-painted COLORSTEEL MAXAM®, warranted against corrosion for up to 50 years inland. Installed on a typical Waikato home, a longrun re-roof costs about $18,000–$40,000, or roughly $110–$220 per m² of roof.
What is longrun roofing?
“Longrun” describes how the roof is made, not a brand. New Zealand Steel makes the coated steel coil, and New Zealand roll-formers press it into profiled sheets cut to the exact length of each roof run. Because one sheet covers the whole run, there are no end laps, which means fewer places for water to get in.
Longrun vs “roofing iron”
Plenty of people still call it roofing iron. Until the 1980s, corrugated iron was New Zealand’s most common roofing: steel sheet galvanised with zinc. It has since been largely replaced by steel with an aluminium-zinc coating, such as ZINCALUME®, which is the base for today’s painted COLORSTEEL. So “longrun iron”, “corrugated iron” and “longrun steel” usually mean the same kind of roof. The steel is just better now. More in is longrun the same as corrugated iron?
Longrun profiles: corrugate or trapezoidal rib?
Both profiles are longrun and come in the same steel. The choice comes down to the look of the building and the pitch of the roof.
| Corrugate | Trapezoidal rib | |
|---|---|---|
| Look | The classic Kiwi wave | Bold, flat-topped ribs with a cleaner, modern line |
| Minimum pitch | 8° for standard corrugate (16.5 mm), lower for deeper corrugate | 3–4°, depending on rib height |
| Suits | Villas, bungalows, 1950s–70s homes, character buildings | Modern homes, new builds, lower pitches, sheds and commercial roofs |
The minimum pitches come from the NZ Metal Roofing Manufacturers’ Code of Practice. Low-pitch roofs and architectural designs can also use secret-fix and standing-seam longrun profiles. For corrugate in depth, see our corrugate guide, and for older homes, re-roofing Hamilton’s older homes.
The steel: COLORSTEEL MAXAM®
Most longrun on Waikato homes is pre-painted COLORSTEEL®. The current product, COLORSTEEL MAXAM®, has replaced Endura® and Maxx®. It’s built on a ZINCALUME® steel base and made for almost all New Zealand conditions, from inland to coastal. Its warranty depends on how far the building is from the sea:
| Environment | Typical location | Corrosion warranty | Paint warranty |
|---|---|---|---|
| Mild | 5 km+ from breaking surf (most of the Waikato) | Up to 50 years | Up to 18 years |
| Moderate | About 500 m–5 km from surf, or near calm salt water | Up to 40 years | Up to 18 years |
| Severe | About 100 m–1 km from surf, harbour foreshores | Up to 30 years | Up to 15 years |
| Very severe | About 25–500 m from the high-water mark | Up to 20 years | Up to 15 years |
Longrun usually comes in 0.40 mm or 0.55 mm steel. More on the product and warranty in our COLORSTEEL guide.
How much does longrun roofing cost?
These are installed prices, including strip-off, sheets, flashings, fixings and labour. Prices for sheets alone from a supplier are much lower, but they don’t include any of that work.
| Building | Approx. roof area | Job | Typical range (2026) |
|---|---|---|---|
| Single-storey 3-bedroom | 140–170 m² | Old iron to corrugate, MAXAM® | $18,000–$26,000 |
| Single-storey 4-bedroom | 180–230 m² | Old iron to trapezoidal rib, MAXAM® | $24,000–$34,000 |
| Two-storey home | 130–170 m² | Old iron to corrugate, scaffold included | $26,000–$36,000 |
| Single-storey 3-bedroom | 150–180 m² | Concrete tiles to longrun | $28,000–$40,000 |
| Commercial or industrial | any | Factory, warehouse, shop or farm building | $100,000–$450,000 |
Coastal jobs use the same MAXAM steel and add travel. For how far from the sea each warranty applies, see steel roofs near the coast. For what moves the price, see what a metal re-roof costs in the Waikato.
Is longrun steel roofing worth it?
For most Waikato buildings, yes. Spread over its life, it usually costs less per year than the alternatives. On a 150 m² roof at about $130 per m², a longrun re-roof costs around $19,500. Over 30–50 years, that’s roughly $390–$650 a year. A roof coating at about $60 per m² costs around $9,000, but buys 5–15 years, which is about $600–$1,800 a year, and you still need a new roof at the end. See new roof costs and choices for the full comparison.
Who longrun suits
- Owners who want one roof for decades. Up to 50 years of corrosion warranty inland, and very little upkeep beyond rain washing.
- Exposed sites. Fixed sheets that run the full length handle Waikato wind and heavy rain well.
- Homes coming off heavy tiles. Steel is far lighter than concrete or clay tiles, which takes a large load off the frame.
- Classic or modern looks. Corrugate keeps a character home looking like itself, and rib suits a modern build.
- Homes, farms and businesses alike. The same material roofs a villa, a hay barn and a warehouse.
- Anyone thinking about the end of life. Steel is recyclable.
Where longrun is used in the Waikato
- Re-roofing homes. Replacing old iron or tiles with new longrun is the most common job. See longrun re-roofing in Hamilton and the Waikato.
- New builds. Trapezoidal rib suits new builds as well as a modern look. CTR quotes straight from building plans and fits the start date to the build programme. See longrun on new builds.
- Farm sheds and rural buildings. Longrun covers big spans quickly. See longrun for sheds and farm buildings.
- Commercial and industrial. Factories, warehouses and shops. See commercial longrun roofing.
- Spouting. Continuous (longrun) spouting is roll-formed to length too. See longrun spouting and downpipes.
How longrun roofing is installed
- Measure. Every run is measured so the sheets can be rolled to exact length.
- Strip the old roof, if it’s a re-roof, and check the battens or purlins. See why the old roof comes off.
- Underlay goes on to manage condensation.
- Sheets go on in one length, fixed with screws rated for the site. On very long runs, the Code of Practice requires allowance for expansion: a dark steel sheet can grow by about 8 mm over 10 m on a hot day. End laps are avoided wherever possible. Where a run is too long to transport, a stepped joint can replace an end lap. See how long a longrun sheet can be.
- Flashings and ridging are folded to fit, and swarf (metal filings) is swept off so it can’t rust-mark the new paint.
CTR re-roofs most homes in 2–4 days, and its installers hold LBP Roofing licences, with a Record of Work on every consented job. Like-for-like re-roofs usually don’t need consent. In Hamilton, see Hamilton City Council consent for a re-roof.
Caring for a longrun roof
Rain washes most of a longrun roof clean. COLORSTEEL asks owners to clean the areas rain doesn’t reach, such as under eaves, around spouting and below fixtures, and to keep leaves out of valleys and spouting. Those are the conditions for its warranty. Wondering about rain noise, dents or wifi? See the biggest problems with metal roofs, or read why metal roofing suits Waikato homes.
Planning a longrun roof?
CTR Roofing uses COLORSTEEL MAXAM® on every job, and most Waikato homes are re-roofed in 2–4 days.
Or call 0800 287 763
Longrun roofing questions
Is longrun roofing the same as corrugated iron?
Corrugate is one longrun profile. “Corrugated iron” was the old galvanised steel version, and today’s longrun corrugate is aluminium-zinc coated steel, usually pre-painted COLORSTEEL. Trapezoidal rib is the other main longrun profile.
How long can a longrun roofing sheet be?
Long enough to run from ridge to spouting on almost any home. Sheets are rolled to the length of each run. Very long runs on big sheds and factories need extra allowance for expansion, and where a sheet is too long to transport, a stepped joint replaces a lap.
How long does a longrun roof last?
COLORSTEEL MAXAM® is warranted against corrosion for up to 50 years in mild environments, which covers most of the Waikato, with a paint warranty of up to 18 years. Closer to the sea, the terms are shorter.
What pitch does a longrun roof need?
Standard corrugate needs at least 8°. Trapezoidal rib can go down to 3–4°, depending on rib height. Very low roofs may need a deeper rib or a secret-fix profile.
Can longrun replace a tiled roof?
Yes. Concrete or clay tiles come off and longrun goes on, which takes a large load off the frame. Going from tiles to steel can change the timber the new sheets fix to, so it needs checking before the job is priced, and it costs more than replacing old iron.
Sources: NZ Metal Roofing Manufacturers: minimum pitch · Code of Practice: thermal expansion · Code of Practice: end laps · NZMRM longrun installation guide · COLORSTEEL warranty · COLORSTEEL MAXAM® · Te Ara: building materials
Related: Metal roof replacement in Hamilton · COLORSTEEL roofs explained · Corrugated iron roofs · What a re-roof costs · Longrun vs corrugated iron · How long longrun sheets can be · Re-roofing FAQs
Written by Corey and the CTR Roofing team, Hamilton. Updated October 2026.