Repairs & Handyman · 27 February 2026 · Cameron Veerstagh
Door and Window Seal Repairs After Darwin's Wet Season
Darwin's wet season batters door and window seals hard — here's how to assess the damage, what repairs cost, and what to fix before the next build-up.
By the time Darwin's wet season winds down in April, most homes have taken a hiding. It's not the dramatic damage that gets you — it's the creeping kind. Door seals that swelled and then cracked. Window sealant that lifted at the edges and let moisture track behind the frame. Weatherstripping that was marginal in October and is now completely flat. April and May, when the knock-em-down storms are fading and the dry air starts to arrive, is the right time to do a full seal audit before you forget about it for another year.
What the wet season actually does to seals
Darwin's wet season runs from November through April, with humidity sitting at 85–95% for months at a stretch. That environment is hard on every polymer and adhesive in your home. Rubber door seals absorb moisture and swell, then dry out and crack. Silicone caulking around windows becomes brittle when the UV hits post-wet — and Darwin's UV index is consistently extreme. Foam weatherstripping compresses under door cycles and loses its memory.
Coastal suburbs cop it worst. Properties in Nightcliff, Coconut Grove, and Larrakeyah deal with salt air on top of the humidity, which accelerates the degradation of aluminium window frames and any metal components in door hardware. If your home is within a kilometre of the water, you're on a shorter replacement cycle than inland suburbs like Casuarina or Wanguri.
The specific failure modes to check for
- Perished rubber seals on external doors: Press on the seal around the door frame. If it doesn't spring back, it's done.
- Cracked silicone at window joins: Look for gaps, lifting edges, or discolouration (black mould tracking into the sealant joint is a tell).
- Condensation tracks on internal window sills: If there's a consistent water stain, moisture is getting in somewhere.
- Sticking or dragging doors: Timber door frames swell in the wet. If your door still sticks well into May, the frame may have taken on water and the seal join is compromised.
- Foam tape weatherstripping under external doors: Run your hand along the bottom gap at night with a torch outside. If you can see light, insects and moisture are getting in.
DIY repairs vs calling a tradesperson
Replacing foam weatherstripping on a door is a legitimate DIY job if the frame is sound. Hardware stores stock self-adhesive foam and rubber D-profile seal in lengths suitable for standard Darwin door sizes. Budget $15–$30 for materials, allow an hour, and you're done.
Re-caulking a window is also within reach if you're careful about prep. The most common mistake is applying new silicone over old — it bonds to the old sealant, not the substrate, and fails within months. You need to fully strip the old sealant with a scraper and silicone remover, clean the surface with methylated spirits, and apply a fresh bead. Use a silicone product specifically rated for exterior use and UV exposure. Standard bathroom silicone breaks down quickly in Darwin's sunlight.
When to stop DIY and call someone
If you find moisture has tracked behind the window frame and reached the internal wall, the repair scope has changed. Plasterboard that's been damp for months may be harbouring mould in the cavity. That's not a sealant job — it's a mould remediation and plastering job. Similarly, if a timber door frame has absorbed enough moisture to warp or delaminate, the frame may need replacing before a new seal will seat properly.
The other scenario is aluminium window frames with failing perimeter sealant on multi-storey homes. Working safely at height with proper tools and surface preparation is a tradie job, not a weekend DIY job.
What the repairs cost in Darwin
For a straightforward seal replacement on a single external door, a Darwin handyman will typically charge $150–$250 including materials and labour, depending on the seal type and condition of the frame. A full window re-seal on a standard aluminium-framed louvre or casement window runs $100–$200 per window for a professional, with discounts if you're doing several at once.
Where costs blow out is when the seal failure has masked a bigger problem. Water damage to a timber window reveal or internal wall can push repair costs to $1,500–$4,000 depending on the extent. Catching and fixing seal failures in autumn before the next wet season is the best value maintenance investment a Darwin homeowner can make.
Planning ahead: what to replace now vs what to monitor
Not every worn seal needs immediate replacement. If the foam tape is slightly compressed but still making contact, monitor it. If the silicone has minor surface crazing but no gaps, clean it and leave it. Prioritise anything with visible gaps, mould intrusion, or evidence of past water tracking.
Add seal checks to your regular maintenance schedule — the annual home maintenance checklist for the Top End covers this alongside the other seasonal tasks that Darwin homes need. At minimum, do a full inspection in May after the wet clears, and again in October before the build-up begins.
The dry season (May–October) is also the best time to tackle any repainting or exterior work that's been deferred — read about dry season home maintenance priorities to plan your list.
When to call AusMCo
If your post-wet-season audit turns up more than a few minor seal replacements — or if you've found evidence of water ingress into walls or frames — AusMCo's home repair team can assess and quote the full scope. We cover Darwin and Palmerston, and we're busiest in autumn for exactly this kind of post-wet repair work. Call 0468 552 206 or get a free quote while the damage is still catchable.