Aluminium window seals — the rubber strips that sit between the glass and the frame — are the first line of defence against draughts, rain, and noise. When they perish, your home loses heat, lets in moisture, and becomes noticeably louder. In Tauranga's coastal climate, window seals typically last 10 to 15 years before UV and salt exposure breaks them down.
Signs Your Window Seals Need Replacing
You don't need a specialist to spot failing seals — the signs are obvious once you know what to look for. Run your finger along the rubber strip around any window frame. If the rubber is hard, cracked, shrunken away from the glass, or crumbles when pressed, it needs replacing.
Other telltale signs include:
- Draughts around closed windows — hold a lighter near the frame edge on a windy day and watch for flickering
- Water leaks during heavy rain — especially in windows facing the prevailing westerly winds
- Increased road noise — degraded seals let sound through that intact rubber would block
- Visible daylight gaps — if you can see light around a closed window, the seal has failed
- Condensation between panes — in double-glazed units, moisture between panes means the perimeter seal has broken down
Why Tauranga Homes Are Particularly Affected
The Bay of Plenty gets around 2,100 hours of sunshine per year — among the highest in New Zealand. That UV exposure is the primary killer of rubber window seals. Add in salt air from the coast (particularly for homes in Mt Maunganui, Omanu, Arataki, and Papamoa Beach) and you have an environment that degrades rubber faster than inland regions.
North and west-facing windows cop the worst of it. I regularly see homes in Bethlehem and Otumoetai where the north-facing seals are completely perished while the south-facing ones still have years of life left. Targeted replacement of the worst-affected windows is often more practical than doing the entire house at once.
What Seal Replacement Involves
Window seal replacement is one of the simplest and most cost-effective window repairs. The process involves removing the old rubber, cleaning the channel in the aluminium frame, and pressing in new rubber of the correct profile. Most residential windows take 10 to 15 minutes each.
The key is using the right rubber profile. New Zealand aluminium joinery uses several different cross-section shapes depending on the manufacturer and era. Fletcher Aluminium, Altherm, and Bradnam's windows all use slightly different profiles. Fitting the wrong profile means the seal won't compress properly and will fail prematurely. I carry the most common profiles on the van and can source less common ones within a few days.
For rental properties, seal replacement is one of the cheapest ways to meet Healthy Homes draught-stopping requirements. A full house of seal replacements often costs less than replacing a single window.
DIY vs Professional Replacement
Window seal replacement is technically simple, but getting the right rubber profile is where most DIY attempts fail. Hardware store rubber strips are generic and rarely match the precise channel dimensions of your joinery. A poor-fitting seal looks messy and fails within months.
Professional replacement ensures the correct profile, clean installation, and a result that lasts another 10 to 15 years. The cost difference between DIY and professional is typically small when you factor in the time spent sourcing materials and the risk of buying the wrong profile.
How Long Do New Seals Last?
Quality EPDM (ethylene propylene diene monomer) rubber seals last 12 to 20 years in typical New Zealand conditions. In Tauranga's higher-UV environment, expect 10 to 15 years for north-facing windows and 15 to 20 years for sheltered south-facing ones. Silicone-based seals last longer than standard rubber but cost more and aren't available for all profiles.
New seals are the highest-value window repair you can do. They fix draughts, stop leaks, reduce noise, and cost a fraction of window replacement.
If you're noticing draughts or water around your windows, a seal assessment takes minutes and costs nothing. I provide free quotes for window and door repairs in Tauranga, Mt Maunganui, Papamoa, Bethlehem, and surrounding suburbs — and most seal replacements are completed the same day.