How to repair a leaking gutter or downpipe
Leaking joints, splits and small holes in gutters and downpipes can be sealed with Instapatch. It moulds to the curve of the gutter and cures hard in daylight.
What you'll need
- Instapatch Standard patches big enough to cover the damage with room to spare. The order wizard will suggest a size.
- UV Curing Primer and a brush for rusty metal or asbestos cement gutters. It's optional on plastic and sound metal.
- Scissors or a sharp knife
- Gloves and protective clothing
- Surface cleaner and clean cloths
- A stable ladder
Before you start
- Clear out leaves and debris, then let the repair area dry out completely.
- If your gutters are asbestos cement, follow the safety steps in our asbestos cement roof guide, and don't brush or scrape them.
- Use a stable ladder and don't overreach. Move the ladder rather than stretching.
- The surface must be dry and free from dust, grease, waxes and loose material.
- Only open the patch when you're ready to use it. It can start to cure within minutes in daylight.
Steps
Clean the area around the leak with surface cleaner and let it dry. On metal gutters, remove any loose rust or flaking paint first.
Prime if needed and let the primer dry fully.
Shape the patch with scissors while it's still in its packet. For a leaking joint, make it long enough to cover both sides of the joint.
Peel the release film from one side, press the patch over the split or joint straight away, and mould it to the curve of the gutter. Apply firm pressure all over.
For a downpipe, wrap the patch around the pipe over the crack. For longer cracks, cut the patch into strips and wrap them in a spiral, overlapping each turn.
If you want to paint the repair, peel off the top film now for a matt finish. Leave it on for a gloss finish that can't be painted.
Leave the patch to cure in daylight. Keep pressing the edges down until it hardens, so the corners don't lift.
Cure timing for this surface
Daylight cures the patch in 15 to 45 minutes, depending on how bright it is. For a downpipe in deep shade, use a UV lamp or torch.
After the repair
Once it has hardened, the patch is waterproof and highly resistant to weather and UV. If you removed the top film, you can paint it to match.
Common questions
Yes. Instapatch Standard works on plastic, and primer is optional on a smooth plastic gutter.
Yes. Once it has cured, the patch is waterproof.
Common mistakes to avoid
- Patching a gutter that's still wet
- Leaving leaves or grit under the patch
- Not covering both sides of a leaking joint
- Overreaching from the ladder
Safety
Wear gloves and protective clothing, and only use Instapatch in a well-ventilated area. It contains polyester compound and styrene, which can irritate the eyes, skin and lungs. If it gets in your eyes, rinse them straight away with plenty of water and get medical advice. If it gets on your skin, wash it off with soap and water.
Storing spare patches
Keep unused patches on end in their original wrapping, somewhere cool, dry, dark and frost free. If a patch is very cold, warm it before use.