Many older houses have cast iron or steel guttering and, as with any metal, this is prone to corrosion over time. It is a good idea to paint metal guttering regularly, ideally once a year, with good quality metal paint. This will also allow you to check the gutter for areas of rust and give you time to treat them before they get too bad.
If you live in a fairly modern house, your guttering will most likely be plastic or aluminium. Aluminium gutters will not rust.
Treating Rust Damage
1. When treating rusted gutters, small patches of rust can be rubbed down with an Emery Cloth or some fine sandpaper, whilst larger patches should be cleaned up with a stiff wire brush or a wire brush wheel fitted in a drill. In either case, rub the rust back until you see only clean, bare metal. You should now paint on a generous coat of rust-neutralising primer (available from most DIY stores) and allow it to dry completely.
2. If the guttering has rusted through in any areas, you will obviously need to make some repairs. Small holes and cracks can be sanded back to bare metal and sealed with roof and gutter sealant. Larger holes might need to be patched using either glass fibre filler or by applying some gutter repair tape. Gutter repair tape is a thin layer of foil coated with a layer of bituminous adhesive, often on both sides of the tape. Make sure the area around the hole is clean and dry before applying either type of patch. The smoother the surface, the better the patch will adhere to the surrounding metal.
3. Wait for the repair patch or filler to harden, before preparing to paint the whole section of guttering. Metal gutters should be painted with a good quality black bitumen or exterior gloss paint. Before you begin painting, it is a good idea to clean the surface of the whole gutter section with a detergent and water solution, or even a mildew-resistant solution. Rinse the gutter and allow it to dry completely before painting.
Galvanized Steel Gutters
Galvanized steel guttering should not rust unless it is damaged in some way and the zinc coating is breached. If you notice rust on a galvanized gutter, clean the area with a non-metal abrasive pad to remove any loose flakes, and then paint the area with a corrosion-resistant metal primer. When this is dry, paint the patch to match the rest of the guttering.
If you believe your rusted gutter has finally gone beyond simple repair, you should consider replacing it completely. Cast iron guttering can be very expensive to replace these days. Luckily, it is possible to buy plastic or PVC guttering which is styled to look like cast iron. This may not be an important consideration for some, but if you live in a period property, cheap-looking plastic guttering and downpipes could really spoil the curb appeal.
Replacing guttering, particularly where you need to replace the brackets as well as the actual gutter channel, can be a tricky job. Try to fit new brackets in line with the position of the old ones if possible. If not, remember that there needs to be a slope in the channel towards the downpipes. This only needs to be slight, so aim for a 10mm fall for every 6m of guttering you fit. Poorly fitted gutters can result in overflowing and potential water damage both outside and inside the house.
When working at height, you need to make sure that you follow some safety rules. A fall from a ladder at the height of the gutter will result in serious injury at the least. Take a look at our Ladder Safety Guide for more information on setting up a ladder properly.