Roof repairsOne fault, one fix, done properly.

Repair, repaint or re-roof?

A repair fixes something specific: one run of flashing, a handful of tiles, a few sheets with rusted laps, a seam on a flat roof. The rest of the roof is doing its job.

It changes when the same fault is everywhere. Rust through most of the iron, nails lifting on every slope, or decramastic tiles bare of chip across the whole roof point towards roof painting or a re-roof. Resene's roofing guide says a badly corroded roof is often better replaced, in whole or by the sheet, than painted. Our restore or re-roof quiz gives a quick first read.

What gets repaired on each kind of roof?

Iron and longrun. Popped nails, screws with perished washers, rust at the laps and sheet ends lifted by wind. On sound iron, swapping nails for screws is a routine fix. More in our guide to popping nails and failing screws.

Scratched COLORSTEEL. NZ Steel doesn't recommend touch-up paint on any COLORSTEEL product. Minor scratches are best left alone, because the metal coating underneath still protects the steel, and widespread damage is fixed by replacing the affected sheets.

Decramastic and pressed metal tiles. Gerard says a single damaged metal tile can be taken out and replaced. Tiles from before the early 1980s may contain asbestos, so a roofer should test before disturbing them. See decramastic roof repairs.

Concrete and clay tiles. Cracked or slipped tiles, and the bedding and pointing under the ridge caps, which Monier says should be redone by a roofing professional using modern flexible compounds. Matching old tiles can take some hunting. More on tile roofs.

Butynol and other membranes. BRANZ says a damaged Butynol roof is repaired by cutting out the damaged part and patching it. Ponding water, most common on flat roofs according to Consumer NZ, is often the real cause to sort. See Butynol repairs.

Flashings and spouting (gutters). The joins around chimneys, skylights and walls, and the channels that carry water away. See roof flashings and spouting repairs.

What makes a repair bigger or smaller?

Getting up there safely. WorkSafe expects fall risks to be managed from any height, and says a single-storey house needs the same fall protection as a two-storey one. For a quick, low-risk task it accepts scaffolding or a harness may not be needed, as long as the measures match the risk. Longer or steeper jobs usually mean edge protection goes up first.

Matching. Dimond advises taking roofing and its accessories from the same manufacturer, because different paint formulations weather differently and end up mismatched. Older tile profiles can be out of production, so second-hand tiles may be the only match.

What's underneath. Rotten battens or wet underlay often only show once a few sheets or tiles come up. A good quote says what happens if the roofer finds more.

Asbestos. If something needs testing, or a licensed removalist, that changes the job and the timing.

Does a roof repair need a building consent or an LBP?

Usually not for a like-for-like repair. Schedule 1 of the Building Act lets you repair and maintain parts of a building without a consent if a comparable product is used, and replace them in the same position. The work must still meet the Building Code.

The catch is early failure. The exemption doesn't cover repairing or replacing a part that failed the Code's durability rules, for example by letting water in. If your roof or flashing is fairly new and already leaking, check with your council before work starts.

Restricted building work, the kind that legally needs an LBP, only applies to work that needs a building consent, so most small repairs don't require one. An LBP with a Roofing licence is still a good sign, and checking one takes a minute.