Roof Restoration vs Full Reroofing:

A Cost & Lifespan Comparison for Kiwi Homes

For most Kiwi homeowners, roof restoration is the lower-cost, lower-disruption option that can add 10–20 years of life if the roof structure is still sound. Full reroofing costs more upfront but delivers the longest lifespan (30–50 years), stronger warranty options, and a full “reset” when the roof’s bones are failing.

Cost comparison (NZD, realistic ranges)

Roof restoration (liquid membranes / coatings)

• Typical range: $60–$120 per m²

• Best for: roofs with surface wear, minor corrosion, or localised leaks

• Usually includes cleaning, rust treatment, repairs, and multi-coat membrane application

Full reroofing

• Typical range: $100–$150+ per m²

• Best for: widespread rust, failing fixings/underlay, structural timber issues

• Includes removal of old roofing and installation of new underlay, flashings, and cladding

Key cost drivers for both

• Roof size, pitch, and complexity

• Access and scaffolding

• Number of penetrations (skylights, chimneys, vents)

• Condition of substrate and exposure (especially coastal environments)

Lifespan & performance

Restoration

• Common planning window: ~10–20 years

• Many membrane systems are designed around ~15 years+ service life when installed and maintained correctly

• Performance depends heavily on preparation quality and the condition of the underlying roof

Reroofing

• Expected lifespan: 30–50 years depending on materials and environment

• Offers the most long-term certainty and fewer major interventions over time

Disruption & timing

Restoration

• Less disruptive: no full tear-off, less noise and waste

• Faster overall project time

• Weather-dependent curing periods

Reroofing

• More disruptive: removal, higher noise, more site traffic

• Typically longer on-site duration

Warranty implications (often overlooked)

Restoration

• Usually comes with a system or coating warranty (commonly 5–15 years)

• Does not reinstate the original roof manufacturer’s warranty

• Coating over metal roofing can affect remaining cladding warranty eligibility

Reroofing

• Enables new manufacturer warranties (often the longest available)

• Separate installer workmanship warranties commonly apply

• Better option if long-term warranty protection is a priority

Environmental impact

• Restoration: significantly less waste; keeps existing materials in place

• Reroofing: higher landfill impact, though metal roofing can often be recycled

• Construction and demolition waste is a major contributor to NZ landfills, making restoration attractive where technically suitable

ROI examples (10–20 year view)

Scenario 1: Roof is structurally sound

• Restoration: ~$11,200 (140 m² × $80/m²)

• Adds ~15 years of life

• ≈ $750 per year of additional roof life

• Strong ROI, especially if selling within 5–10 years

Scenario 2: Hidden structural issues

• Restoration lasts only ~7 years

• Then reroofing still required

• Total cost over time exceeds reroofing upfront

• Poor ROI — reroofing would have been cheaper long-term

Scenario 3: 20-year ownership

• Restoration now + recoat later ≈ $22,000 (simplified)

• Reroof now ≈ $18,000–$20,000

• Reroofing often wins for long-term homeowners

When each option makes sense

Choose restoration when

• Roof structure, fixings, and underlay are sound

• Rust and leaks are surface-level and localised

• You want lower upfront cost and minimal disruption

• You’re comfortable planning future maintenance or recoating

Choose reroofing when

• There’s widespread rust-through or chronic leaking

• Underlay or timber is compromised

• You want maximum lifespan and warranty certainty

• You plan to own the home long-term (15–30+ years)