Five things on your house that fail before you notice

Gutter brackets

The gutters themselves get cleaned. The brackets holding them to the fascia? Nobody thinks about those. Over time - particularly on the north-facing side of a house where the sun does the most damage - the plastic clips that hold gutters in place crack, warp, and let go. One by one.

You won't notice until the gutter sags. Then you'll really notice when a decent downpour sends water straight down the wall instead of into the downpipe - which is when you start getting moisture behind the cladding, and that's a whole different conversation.

Deck fixings

Decks cop a lot. Sun, rain, foot traffic, the odd BBQ grease spill or melted ice cream. Most people treat the deck boards themselves - oil them, sand them back when they get rough - but the fixings that hold the structure together are a different matter.

Coach bolts through the ledger board (where the deck meets the house) are the ones we see fail most. The combination of timber movement and moisture over years works at the connection until it's not doing much of a job anymore. From the top of the deck you'd never know. The posts in the ground are the other common failure point - a post that looks fine at eye level can be rotten right through at the base.

Door and window seals

The rubber or foam seals around external doors and aluminium window frames don't last forever, but they fail so gradually that you never notice the moment they stop working. You just end up with a house that's slightly harder to heat, and a faint whistle on windy days that you've somehow stopped registering.

More importantly - and this is the one people miss - failed seals around windows let moisture track in behind the frame. On a brick or cavity construction house that might not matter much. On a direct-fixed clad house, that moisture has nowhere to go. This is how you end up with rot behind cladding that you discover during a renovation and not before.

"It's always the stuff you can't see from the outside that ends up costing the most."

The fix, when it's just the seal, is cheap and takes twenty minutes per door. The fix once the frame or surrounding timber is affected is considerably less fun.

Smoke alarm batteries

I know. You know. Everybody knows. And yet every house I go into that was built more than a decade ago has at least one alarm that chirps apologetically when I test it, and one more that's been detached from the ceiling and left on a shelf because the chirping got annoying.

NZ law requires working smoke alarms in every bedroom, in every room connecting to a sleeping area, and within three metres of each bedroom door. The fine for a landlord who doesn't comply is significant. But beyond compliance - this is the one on the list that kills people, and it kills them in houses where the owners thought they had it sorted.

If your alarms are the 9V battery type, change the batteries annually - pick a date and do it. If they're older than ten years, replace the whole unit. Modern photoelectric alarms with sealed 10-year batteries cost about $25 and remove the problem entirely.

Exterior trim and window stops

The thin bits of timber that sit against window frames, along rooflines, and at the junction between different cladding materials - the trim - is the first thing that fails on the outside of a house. It's often the last thing to get painted. It takes the weather directly. And when it starts to go, it tends to do so at the joints and the bottom edges, where water sits.

Failed trim isn't just cosmetic. Those joints and edges are where water gets behind the cladding. It's also where insects get in, where heat escapes, and where a $200 re-caulk and paint job, left alone for a couple of years, becomes a $2,000 re-cladding section.

Walk around your house on a sunny day and really look at the trim. Run your finger along the bottom edge of any horizontal piece. Any softness, any paint that flakes to bare grey timber, any caulk that's cracked and pulling away - that's the start of something.