Are your property's piles in good order?
Piles are short timber or concrete posts embedded in the ground under your house that support the rest of your house. Piles support the bearers, which in turn support the joists under the floor of your house.
If your house sits on damaged timber or concrete pile foundations, it can fall off the piles during an earthquake.
- In general
Are the piles:
- standing upright
- evenly supporting the bearers
- not weakened or exposed by ground excavation or being too close to the top of a bank?
- Timber piles
Are your timber piles showing signs of rot or borer damage when you jab a screwdriver or knife into the pile?
- Concrete piles
Are your concrete piles cracked or crumbling?
If your piles are damaged, misaligned or undermined, they need to be repaired or replaced. This isn’t an easy task, so get professional advice.
Is your house properly tied to pile foundations?
If your house is not properly tied to its pile foundations, it can slide off the piles in an earthquake.
- Are the pile / foundation connections in good condition?
Check the connections between the:
- bearers and the piles
- bearers and the joists.
They should not be loose, rusted or broken.
Make sure all your piles are connected to bearers and fix any broken ones.
There are special fixings on the market that can be fitted to existing concrete and timber piles.
Insert a hole through the concrete piles near the top, roughly the same distance from the top and each side of the pile.
Thread wire through the hole and fix it to the opposite sides of the bearer.
Use galvanised wire and fasteners unless your house is located within 500 metres of a coastline or harbour – in which case, use Z-nails and skew nails made of stainless steel so they don’t rust.
Connect timber piles and bearer together using Z-nails, one on each side of the pile and bearer. Place skew nails into the bearer to fix it to the top face of the pile.
No pile connections
If you have no pile connections at all, consult a building professional.