Leaking or overflowing uPVC guttering does not always mean the whole system needs replacing. Start by finding exactly where the water is escaping or backing up, then check the fitting, support and fall around that point.
If you are repairing an older system, identify the gutter profile before buying parts. Half round, square and deepflow guttering use different fittings, even when the parts look similar.
Gutter leaking at a joint
If water is leaking from a union between two lengths of gutter, check the union itself before reaching for sealant.
On the Freeflow system, the union bracket should be fixed securely to the fascia rather than left floating. The gutter should also sit at the expansion marks inside the fitting so it can move as temperatures change. If the gutter has pulled back, the fitting has moved or the seal is damaged, reseat the gutter or replace the union as needed.
Normal gutter unions are designed to seal with their fitted gaskets. Do not simply cover a leaking gasketed joint with sealant. Follow the fitting manufacturer's instructions; Freeflow specifically calls for waterproof sealant where adaptor connections require it.
Shop replacement fittings for half round guttering, square guttering or deepflow guttering.
Gutter leaking from the end
A leak at the end of a run usually means the stop end is not seated correctly, the seal is damaged, or the fitting itself has cracked or distorted.
Check that the stop end matches the gutter profile and is fitted fully. If the fitting or seal is damaged, replacing the stop end is normally a better repair than trying to patch it externally.
Water sitting in the gutter
If water pools instead of travelling towards the outlet, check the fall. A common DIY mistake is setting the fall in the wrong direction or trying to install perfectly level and finding that the fascia itself is not truly level.
Our normal approach is to position the outlet first, measure from the outlet to the end of the run, divide that distance by 600 and round the required drop up to the nearest full millimetre. Use a string line to set the bracket positions so the gutter consistently falls towards the outlet.
For the full layout method, see How to Fit Guttering & Downpipes.
Sagging guttering or poor support
Check for broken, loose or missing fascia brackets. Freeflow specifies fascia brackets at no more than 1m centres, with a bracket within 150mm of stop ends and angles.
Closer spacing can be sensible on roofs that regularly collect moss, leaves or debris from overhanging trees. Keep the brackets evenly spaced and, if in doubt, bring them closer together rather than stretching the spacing further.
Guttering overflowing in heavy rain
Start with the simplest causes. Check the gutter, running outlet and downpipe for leaves, moss or other debris. Clear any blockage and test the system with a hose or bucket of water.
If the gutter is clean but water still sits or flows away from the outlet, re-check the fall and bracket positions. If the system is clean, correctly supported and falling towards the outlet but still cannot cope during heavy rain, gutter capacity may be the issue. Compare Half Round, Square and Deepflow guttering before changing the system.
How to clear a blocked downpipe
Start at the running outlet and remove any visible debris. If the downpipe system includes an access pipe, use the access point to reach the blockage rather than dismantling more of the system than necessary.
Once clear, flush the pipe with water and check that it discharges freely. If the downpipe itself is clear but water backs up from the drain or connection below it, the restriction may be further downstream rather than in the downpipe.
Replacement pipes, sockets, access fittings, clips, bends and shoes are available in our downpipes and fittings range, including 68mm round downpipes and 65mm square downpipes.
Downpipe leaking at a joint
Check that the pipe is properly engaged in the socket and that the joint has not pulled apart or cracked. Freeflow also requires 10mm of expansion allowance at the top of the downpipe, so a pipe fitted too tightly can create problems as it moves with temperature changes.
If a socket or section of pipe is cracked, replace the damaged part rather than relying on tape or an external patch.
Matching replacement gutter fittings to an older system
Common uPVC gutter sizes are fairly standard, so replacing half round with half round or square with square will often be straightforward. There are still differences between systems, though.
If possible, bring a small piece of the old gutter or fitting with you so the replacement can be physically matched before you buy it. This is much more reliable than judging compatibility from the shape alone.
How often should guttering be checked?
Freeflow recommends cleaning rainwater systems at least once a year, with more frequent checks where trees or windblown debris are likely to cause blockages. It also recommends checking that gutters, downpipes and fittings remain secure and that gutter lengths have not moved beyond the expansion marks in their fittings.
After any repair, test the system with water before considering the job finished. It is much easier to correct a joint, fall or blockage while you are still working on it.
For replacement guttering and fittings, see our full Guttering, Downpipes & Fittings range.
