Roof Restoration vs Re-Roofing: Which One Does Your Roof Need?

The short answer

Most Sunshine Coast roofs that look finished are not. A concrete tile roof that has gone chalky, grown lichen and lost its ridge mortar looks worse than it is, because the parts that have failed are the surface coating and the pointing, not the tiles themselves. Those are the exact things a roof restoration replaces. The tiles stay, the broken ones get swapped, the ridges get re-bedded and re-pointed, and the whole roof goes under a new membrane.

Re-roofing is for a different problem. When the tile body has gone soft and porous, when battens have rotted, when a metal roof has rusted through rather than just gone dull, or when the frame has sagged, there is nothing left to restore. Then the old roof comes off and a new one goes on.

The trick is knowing which side of that line your roof sits on. We look at it from satellite imagery first, then from the roof itself. Below are the signs we check, what each option costs, what approvals apply and how long each one lasts.

Signs your roof can be restored

These problems look bad but are all fixed by restoration:

• Faded or chalky colour. Concrete tiles are coloured by a surface coating, and that coating fades under Australian UV over 15 to 25 years. The tile underneath is fine.
• Moss and lichen. The same source notes that lichen acids eat the coating. A pressure clean removes the growth and the new membrane seals the surface.
• Cracked ridge mortar. Mortar bedding is expected to crack within 8 to 15 years. Re-bedding and re-pointing fixes it.
• A handful of broken tiles. Cracked or slipped tiles are replaced one at a time, and the roof is otherwise sound.
• Rusty valleys and flashings. These are replaced as part of the repair stage.
• A dull but solid Colorbond roof. Surface rust and chalking come up with a clean and coat. See metal roof restoration.

The tile body itself lasts a long time. Concrete tiles last 30 to 50 years or more and terracotta 50 to 100 or more, which is why an older brick-and-tile home in Mountain Creek is usually a restoration job, not a replacement.

Signs your roof needs replacing

Sometimes restoration would be money wasted. We recommend re-roofing when we find:

• Tiles breaking underfoot across the roof. A few cracked tiles is normal. When they crumble wherever we step, the tile body has gone.
• Porous tiles. Old concrete tiles that soak up water instead of shedding it will keep leaking under any coating.
• Rotten or sagging battens. If the timber under the tiles has failed, the tiles have to come off to fix it. See our guide on why tiled roofs leak.
• Rusted-through metal. Pinholes and rust holes in Colorbond or galvanised sheets cannot be coated over. Surface rust can; holes cannot.
• Long-term leaks that have damaged the frame. Water that has been getting in for years can rot rafters, and that is structural.
• Pitch problems. AS 2050:2018 sets a minimum pitch of 15 degrees for roof tiles. A roof built flatter than that will keep letting water past the tiles no matter what is done to the surface.

Our tiled roofing team does re-tiling and new tiled roofs, so we have no reason to push you either way. If the roof can be restored, we say so.

What each option costs

The gap is large. The whatsthedamage Sunshine Coast roofing guide lists a full tile roof restoration at $3,875 low, $6,300 typical and $10,650 high. A single-storey re-roof is listed at $9,700 to $24,250, with $15,500 typical.

Those are guide ranges from a published cost guide, not our prices. A restoration on a big two-storey roof with solar panels can cost more than a re-roof on a small cottage. What matters is the condition of your roof and what it needs. Run the cost calculator for a starting range, then ask us for a satellite estimate. We wrote a full breakdown in our Sunshine Coast roof restoration cost guide.

Approvals and rules

Restoration, repairs and painting are exempt from building approval. Sunshine Coast Council lists repairs and maintenance as work that does not need approval, and the exemption sits in Schedule 1 of the Building Regulation 2021. Re-roofing is different. Where you are re-roofing more than 20% of the roof, building approval is required, and the new roof has to meet current standards.

For a tiled re-roof that means AS 2050:2018, which covers bedding and pointing, mechanical fixing of tiles and sarking. For wind loads, the Sunshine Coast sits in AS/NZS 1170.2 wind Region B, with design winds of 162 to 198 km/h. A local wind hazard study found gusts around 5 m/s above the Region B figure and older housing more vulnerable, which is one reason a new roof has to be tied down properly.

Either way, the contractor needs a QBCC licence for work over $3,300. We cover the detail in Do You Need Council Approval for Roof Work?

How long each option lasts

A restoration is not a short-term fix. Canstar says restorations last approximately 15 to 20 years. The membrane systems we use back that up with written manufacturer warranties: Industrial Roof Coatings Roof Refresh carries 10 years, Roof Protect 15 years and the 20 Year Roof Protect system 20 years on concrete tiles. Those warranties apply only when an approved applicator does the work. On top of that, our workmanship carries a 10-year warranty (terms apply).

A new tiled roof resets the clock on the tile body, so the 30 to 50 year concrete figure or the 50 to 100 year terracotta figure starts again. The coating on new concrete tiles still fades the same way, so a new roof from today will likely want a restoration down the track too.

Salt air shortens both. Homes near the surf at Buddina, Peregian Beach and Sunshine Beach see more metal corrosion than homes at Palmwoods. Our guide on salt air and your roof explains why.

How we help you decide

We do not decide from the ground. The first step is a satellite estimate, which tells us roof area, ridge length and pitch. The second is a site inspection where we walk the roof, lift tiles, check the battens from the roof cavity where we can, tap the ridge mortar and look at every valley and flashing. Then we tell you which option the roof needs and why.

If it is a restoration, the quote covers the pressure clean, repairs, re-bedding and re-pointing, primer and two membrane coats, with our 10-year warranty (terms apply). If it is a re-roof, we quote that instead and explain the approval process. If it is something in between, such as a roof that only needs ridge re-pointing and a few repairs, we quote only that.

You can use the roof health check to get a feel for where your roof sits before you call. Then contact us and we will start with the satellite estimate. Photos of past jobs are in the before and after gallery.

Sources

• whatsthedamage roofing cost guide, Sunshine Coast
• Canstar roof restoration cost guide
• Roof Tile Recyclers on tile colour fading
• Your Local Roofers on concrete tile lifespan
• Sunshine Coast Council: what needs building approval
• Agile Approvals on re-roofing more than 20%
• AS 2050:2018 Installation of roof tiles
• Industrial Roof Coatings 20 Year Roof Protect

Tyler Czebotar, Seaspray RestosQBCC licensed roof restorer on the Sunshine Coast, 15 years in roofing. About