Grey, ribbed sheets on an older carport? Assume asbestos
ASSEA, the federal asbestos agency, lists carports among the places asbestos is found, and says homes built or renovated before 1990 probably have some. If your carport roof is grey cement sheeting, don't cut, drill, sand, stand on or pull it off. It's illegal in every state to water-blast asbestos. A licensed removalist has to take it off before the new roof goes on, as our asbestos roof replacement page explains.
Why carport roofs fail
Carports are open underneath, so wind gets under the sheets and pushes up as well as down. Over years that loosens screws, enlarges the holes and lets sheets flap. A roof that rattles in a gusty change is telling you the fixings are going.
Flat carports also tend to hold leaves and water. Ponding sits on the sheets and at the laps, which is why rust usually starts at the low end and along the gutter. Polycarbonate fails differently: sun breaks down sheets laid with the UV side facing the wrong way, and Laserlite says the sheets need oversized holes and screws done up just enough to stop rattling, because they expand and contract. Sheets screwed down hard can crack at the fixings.
How a roofer re-sheets a carport
Old sheets come off and the purlins (the horizontal members the sheets screw to) get checked for rust or rot. Steel frames with surface rust can be treated; members rusted through need replacing.
If the carport is too flat, the roofer may pack one side to improve the fall. New sheets go on with fresh screws at the spacing the manufacturer specifies for wind, then gutters and downpipes. Where the carport meets the house, the join needs proper flashing, because that's where a lot of carport leaks actually start.
Questions to ask the roofer
- Are the purlins and posts sound enough to keep, or do any need replacing?
- What fixings and spacing are you using for wind at our address?
- How will you flash the join to the house or the house gutter?
- If the old sheets are fibro, who removes them and is that in the price?
What you can safely do, and what's for a roofer
You can
- Look up from underneath for daylight through screw holes, rust and cracked sheets
- Note where water drips or pools after rain
- Stay off the roof itself: Safe Work Australia says roofs of asbestos sheets, polycarbonate or corroded metal are likely to be fragile
Leave to a roofer
- Removing and replacing sheets and screws
- Purlin, post and fall repairs
- Flashing to the house and gutter work
- Anything involving cement sheeting, which needs a licensed removalist first
If it were our carport
If the frame is sound, we'd re-sheet rather than rebuild, and we'd pay for new screws throughout rather than reusing old holes. If the roof is fibro, we'd have it tested or treated as asbestos and get the removal done by a licensed removalist before any roofer starts. On a flat carport that ponds, we'd ask for the fall to be fixed at the same time, since new sheets on the same flat frame tend to rust in the same place.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.