Polycarbonate roof replacement removes cracked, brittle or leaking patio and pergola sheets and fits new ones with the right fixings and seals. Sheets expand with heat, so holes are oversized and fixings are sealed. Done properly, the new roof stays watertight and does not split at the screws.
When to replace patio sheets
- The sheets have cracked or split, often around the screws.
- They have yellowed or gone brittle in the sun and break if touched.
- Water drips through at the laps or the fixings.
- Hail or a branch has holed a sheet.
- You want a different look or a different level of light and shade.
How we replace them
- Measure the frame and check the beams and the fixings. A sagging or rotten frame needs fixing first.
- Remove the old sheets and the failed flashings and seals.
- Fit the new sheets on the frame with correct overlaps and the fall your drainage needs.
- Fix with the right screws, with oversized holes and washers where the sheet type needs them, so the sheet can expand without cracking.
- Seal the edges and flashing against the house wall, and check the gutter takes the runoff.
Why sheets split
Plastic roof sheets grow and shrink with temperature. If the screws grip tight with no allowance for movement, the sheet cracks at the hole. Over-tightened screws and the wrong washers cause the same fault. This is the main reason a cheap patio job splits within a few seasons, and it is why we pay attention to fixings.
Sheet types and what they do
| Option | Light and heat | Notes |
|---|---|---|
| Clear or tinted polycarbonate | Lets light through; tint cuts glare and heat | Check UV rating and warranty from the maker |
| Opaque or white sheet | Blocks most light; reflects heat | Cooler underneath, darker space |
| Metal sheet | Blocks light; conducts heat unless insulated | Strong and long-lived; noisier in rain |
We help you choose the sheet that suits how you use the space. Ask the maker for the warranty terms of the product you pick, and get them in writing.
Attached patios and the main roof
A patio roof is joined to the house at a flashing. If that joint leaks, the water runs down the wall into the home. We check and reseal it during the job. For metal patio roofs, see Colourbond repairs.
Patio roof leaking? Ring 0430 545 669. If we miss you, leave your suburb and what you can see on the form and we will get back to you.
Questions about polycarbonate and patio roofing
Can you replace just one sheet?
Often yes, if the profile is still available and the neighbouring sheets are sound. If the sheets are old and brittle, replacing the whole roof saves repeat visits.
How long do patio sheets last?
It depends on the product, the UV rating and how well it was fixed. Ask for the manufacturer's warranty in writing, and check what it covers.
Do I need council approval?
Replacing sheets like for like on an existing structure is normally treated differently to building a new one. Check with your council or building surveyor if you are changing the structure.
Can you fix a leaking join at the house wall?
Yes. We reseal or replace the flashing where the patio meets the wall.