Longrun Metal Roofing Tauranga

Why Longrun Is the Default in New Zealand

Longrun metal roofing is what sits on most New Zealand houses, and for good reason. It is light, so it puts very little load on the framing. It is quick to install, which keeps the labour cost down. It sheds water fast, which matters on a low pitch. And because a sheet is rolled to the exact length of the run, a typical house roof has no horizontal join anywhere on it.

That last point is the one worth understanding. An end lap - where two sheets overlap partway up a roof plane - is the single most common place a metal roof leaks, because water driven uphill by wind can get under it. Rolling to length removes that failure point entirely. It is why we order after measuring rather than working from stock lengths, and why longrun needs a little lead time.

Profiles

• Corrugate. The classic rounded profile that reads as "New Zealand roof". Suits villas, bungalows, sheds and anything where you want the traditional look. Very forgiving over slightly uneven framing.
• Trapezoidal. A squarer, more angular rib. A more contemporary look, and the deeper ribs span further, which suits larger buildings and lower pitches. This is what most new builds in Pyes Pa and Papamoa are going up with.
• Standing seam and tray. The flat-pan, raised-seam look on architectural homes. Covered on our architectural tray roofing page, because it is a different install altogether.

Coastal Grading: the Thing That Decides How Long It Lasts

This matters more in Tauranga than almost anywhere. Mount Maunganui, Papamoa, Omokoroa, Matua and Waihi Beach all sit in a marine environment, and salt in the air attacks steel continuously. The whole roof is only as good as its worst-specified component.

What changes with distance from the sea:

• The substrate. Standard zinc-aluminium coated steel is fine well inland. Close to breaking surf you want a more corrosion-resistant substrate, and there are products made specifically for severe marine exposure.
• The paint system. Coating grade affects both corrosion resistance and how long the colour holds before it chalks.
• The fixings. A stainless fixing in a coastal zone costs more and is not optional. Screws are the first thing to go, and a roof held down by failed fixings is not a roof.
• The flashings and the spouting. There is no point specifying the sheet carefully and then bolting standard flashings to it.
• Dissimilar metals. Putting the wrong two metals in contact in salt air sets up galvanic corrosion, and it will eat through the softer one. It is why an unspecified "we will just use what is on the truck" approach fails early near the water.

Manufacturer warranties are conditional on the product being correct for the environment and on the roof being washed down where it is not rain-washed. Under an eave or a carport, salt builds up and never gets rinsed off. We will tell you which parts of your roof that applies to.

Colour

COLORSTEEL and Colorcote both carry a wide standard range, and this is the decision people agonise over most. Two pieces of practical advice: look at a real sample outdoors rather than a swatch on a screen, because the colours read very differently in Bay of Plenty sunlight; and darker colours run hotter, which matters if the roof space is not well ventilated. Beyond that it is a matter of taste, and we will get samples to you.

Longrun goes on new builds and re-roofs alike, and we handle the spouting and downpipes at the same time so the whole rainwater system matches.