17/08/2026
Heat-Proof Your Rainwater Installation This Summer
With temperatures rising, it's important to remember that plastic rainwater systems expand in the heat and contract in colder weather. Installing your guttering correctly can help prevent leaks, buckling, and costly callbacks.
✅ Top tips for installers and contractors:
🔹 Allow for expansion and contraction
Wavin Osma gutter fittings include a built-in expansion line, positioned approximately 10mm from the stopper, giving the gutter room to move as temperatures change. It is important to install the gutter to the expansion line.
🔹 Don't push guttering up to the stopper
If installed too far in, the gutter has nowhere to expand in hot weather, which can lead to bending and buckling.
🔹 Don't install short of the expansion line.
If installed too short on a hot day, the gutter may contract in colder temperatures and pull away from the seal, causing leaks.
🔹 Check brackets and fittings
Make sure all brackets and fittings are securely fixed to the fascia. A loose section can place stress on the system and lead to performance issues. Also, if a fitting requires a bracket such as a gutter union ensure one has been fitted.
🔹 Don't forget the downpipes
Leave a 10-12mm gap between the top of each downpipe length and the fitting it connects into to allow for movement.
For enhanced retention, Wavin Osma gutter fittings also feature an extra-wide seal positioned close to the fitting edge, providing improved grip and helping retain the gutter securely.
See the video here https://hubs.la/Q04t1XFh0
