Aluminium doesn't rust, but it does corrode — and in Tauranga's coastal environment, that corrosion happens faster than most homeowners realise. Salt-laden air from the Bay of Plenty attacks aluminium surfaces, hardware, and seals year-round. A simple maintenance routine every 3 to 6 months can double the lifespan of your windows and doors and prevent expensive repairs down the track.
How Salt Air Damages Aluminium Joinery
Aluminium naturally forms a thin oxide layer that protects it from corrosion. Powder coating adds a second layer of protection. But salt deposits break down both barriers over time through a process called pitting corrosion — tiny holes form in the surface, exposing fresh aluminium to further attack.
The NZ Building Code classifies exposure zones by distance from the coast. Much of Tauranga falls within Zone D (severe marine) or Zone C (moderate marine):
- Zone D (within 500m of the coast) — Mt Maunganui, Omanu, Papamoa Beach, Pilot Bay, Arataki. Maximum salt exposure. Joinery needs washing every 3 months minimum.
- Zone C (500m to 5km from the coast) — Bethlehem, Greerton, Otumoetai, Welcome Bay, Brookfield. Moderate salt exposure. Washing every 6 months is usually sufficient.
- Zone B (5km+ from the coast) — inland areas like Tauriko, The Lakes, Pyes Pa. Lower salt exposure but still benefits from annual washing.
Wind direction matters too. Windows and doors facing the prevailing onshore winds (northeast to northwest in Tauranga) accumulate salt deposits 2 to 3 times faster than sheltered sides of the house.
The 30-Minute Quarterly Wash
The single most effective maintenance task is washing your joinery with fresh water and a mild detergent. This removes salt deposits before they cause pitting. Here's the routine I recommend to all my Tauranga clients:
- Hose down all aluminium frames — start at the top and work down. Plain water removes most surface salt.
- Wash with warm soapy water — use a soft cloth or sponge with household dish soap. Avoid abrasive cleaners, scouring pads, or anything containing ammonia or bleach — these damage the powder coating.
- Clean the tracks — vacuum sliding door and window tracks to remove sand, grit, and debris. A damp cloth after vacuuming picks up the fine particles. Clean tracks extend the life of ranch slider rollers significantly.
- Check and clean drainage holes — aluminium window frames have small weep holes at the bottom that drain condensation and rain. If these are blocked with dirt or paint, water pools inside the frame and accelerates corrosion. Clear them with a thin wire or compressed air.
- Rinse thoroughly — remove all soap residue with fresh water.
For a typical three-bedroom home, this takes about 30 minutes. Done quarterly for coastal homes and twice yearly for inland homes, it prevents the vast majority of corrosion issues I see across Tauranga.
Hardware Maintenance
Handles, locks, stays, and rollers all have moving parts that need periodic attention:
- Lubricate moving parts — apply a light silicone spray to hinges, friction stays, lock mechanisms, and roller assemblies every 6 months. Do not use WD-40 or oil-based lubricants — they attract dust and salt, accelerating wear.
- Check screw tightness — handles and stays can work loose with regular use. A quick check with a screwdriver twice a year prevents screws from stripping the aluminium threads.
- Inspect for corrosion — look for white powder (aluminium oxide), brown staining (steel component corrosion), or stiffness in operation. Early corrosion on hardware is often fixable; advanced corrosion means replacement is needed.
If hardware is already corroded or stiff, see our guides on window handle replacement and stays and hinges for when repair vs replacement makes sense.
Rubber Seal Care
Window and door seals degrade faster in coastal environments due to combined UV and salt exposure. While you can't prevent rubber degradation entirely, you can slow it:
- Clean seals during your quarterly wash — salt deposits on rubber accelerate cracking
- Apply a rubber protectant — silicone-based rubber conditioner (available from automotive stores) helps maintain flexibility. Apply annually.
- Don't paint over seals — paint makes rubber brittle and prevents it from compressing properly
When seals do perish, replacement is quick and affordable. The key is catching them before water starts leaking through and damaging the wall framing behind the window.
When to Call a Professional
Regular maintenance handles prevention, but some issues need professional attention:
- White chalking or pitting on frames — the powder coating is breaking down. Frames may need recoating or replacement depending on severity.
- Windows or doors that don't close flush — could be rollers, stays, frame misalignment, or a combination. Diagnosis determines the fix.
- Water leaking through closed windows — seal failure, drainage blockage, or frame damage. Needs inspection to identify the source.
- Stiff or seized hardware — if lubrication doesn't free it, internal corrosion has likely progressed too far for cleaning alone.
I provide free assessments for window and door repairs in Tauranga, Mt Maunganui, Papamoa, Bethlehem, and surrounding suburbs. A 15-minute inspection identifies what needs attention now, what can wait, and what's still in good shape — so you're not paying for work that isn't needed.
Thirty minutes with a hose and soapy water every 3 months is the cheapest insurance you can buy for your windows and doors. Salt doesn't stop, so maintenance shouldn't either.