How to fix a leaking gutter joint with tape
A dripping gutter joint is one of the most common call-outs there is. Over time the seals in gutter unions and joints perish, and water starts running down the wall instead of into the downpipe. In many cases you can fix it from inside the gutter with tape, without taking the run down.
What you'll need
- Supraseal® Weatherproofing Tape. 100mm suits most domestic gutter joints, and 200mm or 300mm suits wider box or valley gutters
- A stiff brush, cloths and a suitable cleaner
- Scissors or a sharp knife
- A seam roller or firm hand pressure
Step 1: Make it safe and find the leak
Work from a properly footed ladder or a scaffold tower. Pour a little water into the gutter if you need to find exactly where it's coming through.
Step 2: Clear and clean the gutter
Scoop out leaves and silt, then scrub the inside of the gutter either side of the joint. Remove any algae, old sealant and grime, and let it dry completely. The tape needs a clean, dry surface to bond.
Step 3: Cut and shape the tape
Cut a piece long enough to run well past the joint on both sides, with at least 50mm of overlap. Round the corners. For round gutters, it can help to make small relief cuts in the edges so the tape follows the curve without creasing.
Step 4: Apply from the bottom up
Press the tape into the bottom of the gutter first, then work it up each side, pushing out air as you go. Avoid stretching it. Roll or press it firmly all over, especially along the edges where water will run.
Step 5: Test it
Pour water through the gutter and check the joint from below. If it's still dripping, check the edges have bonded and that the tape runs far enough past the joint.
Tips
- Supraseal® can be painted over to match the gutter colour.
- Work in dry weather. In winter, keep the roll somewhere warm before use.
- For cracked or badly corroded gutters, tape is a good emergency fix, but plan to replace the section.