Rescrew now, or full re-roof? How to actually tell.

A rescrew costs $4,000 to $8,000 on a standard Bay of Plenty home. A full re-roof costs $19,500 to $26,250. That four-times-cheaper option is only worth doing if the roof itself has life left. Here is the test we run on site to decide.

What a rescrew actually does

A rescrew replaces every fixing on the roof — typically a couple of thousand new washered screws — and re-seals every penetration along the way. We also replace flashings that have aged out, re-seal sky domes, and tighten ridge caps.

What it does not do: replace the actual roofing sheets. That is what a re-roof is for. So a rescrew is only a good idea if the sheets themselves are in good condition.

The four-test check

Here is what we look at, in order, when we are deciding for a customer.

Test 1: substrate (the steel itself)

We get up on the roof and walk every sheet. We are looking for:

• Surface rust spots — treatable. Sand, prime, paint. Not a re-roof trigger on its own.
• Through-rust — you can see daylight through the sheet from below. This is a re-roof trigger. No amount of rescrewing will fix a sheet that is full of holes.
• Edge corrosion at the cut ends — common on sheets older than 25 years. If extensive, points toward re-roof.

If 80%+ of the sheets are clean of through-rust, rescrew is still on the table.

Test 2: paint film

Run your fingernail across the painted surface. Then check your finger.

• Clean finger: Paint film is intact. Rescrew is fine.
• Chalky residue on your finger: The paint is starting to fail. Rescrew still works, but you have maybe 5 to 8 years before the colour goes properly.
• Visible flaking, bubbling, or peeling: The film is gone. The steel underneath is exposed and will corrode fast. Re-roof.

A rescrew on a roof that is about to need a recoat is still good value, just budget for the recoat ($8,000 to $12,000 on a 150m² home) in 5 to 8 years.

Test 3: age

Roughly, where you are in the lifecycle:

• Years 0 to 17: Too early. Fixings should still be sound. If you are getting leaks here, something else is wrong — let us look at flashings and penetrations, not fixings.
• Years 18 to 28: The sweet spot. This is exactly what a rescrew is for. Buys you 15 to 20 more years of trouble-free roof.
• Years 28 to 35: Marginal. We will look at substrate carefully. Some roofs in this band are fine, some are tired.
• Years 35+: Almost always re-roof. The paint film and sheet life have run out.

For coastal homes within 3km of the sea, shift every band 4 to 6 years earlier. Salt is brutal on fixings.

Test 4: flashings and ridge caps

The bits at the edges of the roof age at their own pace. Flashings are thinner steel, more exposed, and they curl, lift, and corrode faster than the sheets do.

If 70%+ of your flashings are still tight and crisp, they get re-sealed during the rescrew. If they are visibly fatigued, we replace the failing ones at the same time. Adds maybe $1,500 to $3,000 to the rescrew but keeps the roof watertight.

When rescrew is the right call

Textbook rescrew candidate:

• Coloursteel longrun roof, 20 to 25 years old
• No visible through-rust anywhere
• Paint film intact, maybe a touch chalky on the north-facing side
• You can see daylight around the bottom of some screws (they have backed out)
• One or two leaks that have shown up in the last year, traceable to flashings

Rescrew that house, do the flashings, and you have just bought 15 to 20 years for about a quarter of the re-roof price. We do this job every week across BoP.

When you should bite the bullet on a re-roof

• Through-rust visible on three or more sheets
• Paint film flaking off, exposing bare steel
• Sagging between rafters (decking failure underneath)
• Repeated leaks that you have already tried to chase
• You are planning to sell within 3 years and want presentation up
• The roof is 35+ years old and you have already done one rescrew

If two or more of these apply, a rescrew is throwing good money after bad. Re-roof.

What if it is somewhere in between?

Real roofs rarely fall cleanly in one bucket or the other. The honest call is usually a judgment one. We will give you both numbers, lay out what each gets you, and let you decide. Sometimes a rescrew now plus a re-roof in 8 years is the right financial play. Sometimes biting the bullet today saves you doing both jobs.

Either way, we tell you straight. We have walked away from rescrew jobs because we did not think they would last, and we have talked people out of full re-roofs they did not need yet. Honest advice does not always pay us more, and we are fine with that. It is how we keep getting called back.