Long-Run Iron or Corrugate: What Wellington Homeowners Should Know

Metal roofs are everywhere in Wellington, and for good reason. They are light, cope well with wind when properly fixed, and suit the steep pitches and varied shapes of local homes. The terms can be confusing though, so here is a plain guide.

Corrugate and long-run

Corrugate refers to the classic wavy profile seen on villas and baches. Long-run simply means sheets rolled to length so a single sheet runs from ridge to gutter without end laps. Many roofs are both: long-run corrugate. Other profiles, such as trapezoidal ribs, give a more modern look and can carry water well on lower pitches.

Coated steel and coastal exposure

Most new metal roofing is pre-painted coated steel, with COLORSTEEL being a well-known name. Products come in different grades, and the right one depends on how close you are to the sea and how exposed the site is. Homes on the south coast, around Porirua Harbour or along the Kapiti Coast face salt spray that can corrode a lower-grade product faster. Fixings and flashings need to match the sheet so you do not end up with one part rusting ahead of the rest.

Wind zones matter

Wellington has some of the highest wind zones in the country. The number and type of fixings, and how flashings are secured, are set to suit the site. Roof Repair Wellington says it works to the Building Code, including wind-zone and coastal-corrosion requirements. If you have had a sheet lift in a gale, our guide to storm damage covers what to do next.

Looking after it

Wash areas the rain does not reach, like under eaves and verandas, where salt and grime sit. Keep gutters clear, and deal with scratches and surface rust early. A roofer can advise on metal roofing options for exposed sites if you are thinking about replacing or adding to a metal roof.

For homes thinking about a change of roofing altogether, our villa roof questions is a useful read.