PHOTOGRAPHS FROM OUR OWN WORK
What this looks like in practice.
Check the fitting and its support
Rubber seals age and can become displaced. A gutter length may also pull away from its union as it expands, contracts or sags. A drip at a joint needs inspection of both the fitting and the surrounding gutter.
Why plastic guttering clicks as the temperature changes
Plastic guttering expands as it warms in the sun and contracts as it cools. Friction at seals, retaining clips and fascia brackets can briefly resist that movement, then release it in a small slip that produces a click or creak. Occasional clicking can be normal thermal movement; the sound alone does not mean a fitting is broken.
How a gutter can gradually move along its brackets
If one end of a gutter length is restrained while the other can slide more freely, expansion and contraction may not reverse evenly. Different resistance at the supports and joints can allow the gutter to creep along the fascia brackets in one direction over repeated heating and cooling cycles. It can eventually pull too far out of a union, reduce contact with the seal and open a leaking joint. This is a possible mechanism, not something every gutter does or that a photograph alone can prove.
Restore the joint and its allowance for movement
We check how far each gutter end sits inside the union, the fitting fixings, seals, retaining clips, bracket support and alignment. Gutter ends should follow the expansion marks for that particular system, with compatible lubricant where the manufacturer specifies it. The repair should let the gutter move as designed while keeping its joints properly engaged; simply forcing it back, adding sealant or fixing it rigidly can leave the cause unresolved.
Replace before patching
Where compatible components are available, replacing the failed seal or union is normally preferable to covering the joint in sealant. Older or obsolete profiles may call for a limited repair after the alternatives are explained.