Tile, metal and flat roofs each need a different way of mounting solar panels. How tile hooks, sealed metal-roof fixings and tilt frames work, what waterproofing and roof condition checks involve, and how roof type affects the price. Solar panels can be installed on tiled, metal ("tin") and flat roofs, but each needs a different mounting method. On tiles, hooks pass between the tiles and fix to the rafters; on metal roofs, brackets are screwed through the sheeting into the battens or purlins with sealed fixings, or clamped onto the ribs; and on flat roofs, tilt frames angle the panels towards the sun. The roof type changes the labour involved, the waterproofing details, the repairs that may be needed first and, as a result, the final price.
Tile roofs: concrete and terracotta
Tiled roofs are common across Sydney, particularly in established suburbs. The standard method uses tile hooks:
- Tiles are lifted where each hook will go.
- A stainless steel or galvanised hook is screwed to the rafter below.
- The tile is notched or ground where the hook passes, so it sits flat again without being cracked by the hook.
- Rails are fixed to the hooks and the panels are clamped to the rails.
Because the hooks pass between tiles rather than through them, the roof keeps its original water-shedding design, provided every tile is re-seated properly. The main risk is cracked tiles. Terracotta is more brittle than concrete, and old tiles of either kind can break underfoot, so the installation should allow for replacing any that crack and for checking the array area for broken or slipped tiles before panels cover it. Once panels are on, tiles underneath are much harder to reach. Some older tile profiles are no longer made, so matching replacements may have to come from salvaged stock, which is worth sorting out before installation day.
Metal roofs: corrugated and concealed-fix
Metal roofing is usually the quickest type to install on, with two main approaches:
- Corrugated and trapezoidal sheeting: mounting feet are screwed through the crest of the sheet into the batten or purlin beneath, using fixings with sealing washers so each penetration stays watertight.
- Concealed-fix profiles: clamps grip the raised ribs of the sheet, so no holes are needed through the roofing at all.
On metal roofs we check for rust around existing screws, especially near the coast; whether the brackets and fixings are compatible with the roof material, since dissimilar metals can corrode each other; the spacing and condition of battens or purlins; and the wind region, which can call for closer fixing spacing near roof edges and corners, where wind loads are higher.
Flat and low-pitch roofs
Panels can be laid almost flat, but most flat-roof installations use tilt frames, and the choice has real consequences:
| Option | Advantages | Trade-offs |
|---|---|---|
| Flush-mounted, minimal tilt | Lowest profile and wind load, least visible | Water and dirt sit on the glass, and panels at very low angles do not self-clean well in rain |
| Tilt frames fixed to the structure | Better self-cleaning and output; around 10-15 degrees is a common tilt on homes | Higher wind loads, more fixings, possible engineering, and rows must be spaced so they do not shade each other |
| Ballasted frames (weighted, not fixed) | Few or no penetrations through the membrane | Adds significant weight, needs confirmed structural capacity, and mainly suits suitable commercial roofs |
Waterproofing is the critical issue on flat roofs. Every penetration through a membrane needs a proper flashing and seal, frames must not block drainage paths to outlets and box gutters, and older membranes need protecting from foot traffic during the work. On concrete slab roofs, fixings go into the slab and must be sealed so water cannot track in. Where a membrane is near the end of its life, replacing it before the panels go on costs far less than removing the array later to do it.
Roof condition matters on every roof type
Panels commonly last 25 years or more, so the roof underneath needs to last too. Before installation, these issues should be identified and fixed:
- Cracked, slipped or porous tiles, and deteriorated ridge capping
- Rusted sheets, failing screws or perished sealant on metal roofs
- Blistered or cracked membranes, or water ponding, on flat roofs
- Sagging sections that may point to structural problems
- Asbestos cement roofing, which should never be drilled or walked on and must be replaced by licensed specialists first
Our roof suitability checker is a quick first look, but these details are confirmed during the in-person site assessment. Roof and electrical work must always be done by qualified trades, never as a DIY job.
How roof type affects the cost
Our published price ranges for Sydney in 2026 are indicative and already reflect STCs: roughly $4,500-$6,500 for a 6.6 kW system and $6,000-$8,000 for an 8.8 kW system, as outlined on our residential solar page. Where a home lands within a range, or outside it, depends partly on the roof:
- Metal roofs on a single-storey home are often the most straightforward.
- Tile roofs take more labour for lifting, notching and re-seating tiles, plus any replacements.
- Flat roofs add tilt frames, waterproofing details and sometimes engineering.
- Steep pitches, two storeys and difficult access add safety equipment and time on any roof type.
Related works are listed separately in our energy market: Roof Repairs Before Solar from $490, Waterproofing for Solar Installation from $390 and Structural Engineering Certification from $690. All are indicative and confirmed after a site assessment. A good quote lists roof-related items separately rather than folding them into one figure, so you can compare quotes like for like. STC values step down each 1 January, so confirm current values on the official pages before signing.
Next steps
You do not need to know your roof's exact profile before you ask. Request a free quote and our team will inspect the roof type, condition, structure and access in person, then set out any roof-specific items in the quote, such as tilt frames, tile replacements or waterproofing, so you can see exactly what you are paying for.
Frequently asked questions
Will solar panels void my roof warranty?
It depends on the terms of your roofing warranty. Some metal roofing warranties set conditions on penetrations, fasteners and compatible materials, and a recently built home may also carry a builder's warranty. Check your roof documents before installation and share them with us, so the mounting method and fixings can be chosen to meet those conditions wherever possible.
Can panels go on a curved or very steep roof?
Often, with the right equipment and approach. Steep roofs need more safety equipment and time, and very steep pitches may need scaffolding. Curved metal roofs can sometimes carry panels on the flatter section or on specially formed rails, although output can be uneven when panels face different angles. These roofs are assessed individually on site before any price is given.
What happens if the roof needs replacing after panels are installed?
The panels, rails and cabling have to be removed, stored safely and reinstalled by an accredited installer and a licensed electrician, which adds cost to the roofing job. If the roof is likely to need replacing within the next several years, it usually makes sense to do it before solar goes on. Keep your system documents, so the reinstallation matches the original design.
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