Exterior steps that are cracked, wobbly, or rotting are more than an eyesore — they're a genuine safety hazard and can signal deeper structural problems. The good news is that a careful visual and physical inspection can reveal most issues before they become costly repairs. Here's how to check your steps methodically, what to look for, and when to bring in a professional.
Understand What You're Looking At
Exterior steps in New Zealand homes are typically built from timber, concrete, masonry (brick or block), or a combination of these. Each material has its own failure modes. Steps must also comply with the NZ Building Code, particularly Clause D1 (Access Routes), which sets requirements for step dimensions, handrail heights, and slip resistance. If your steps were built or altered after 1992, they should meet these standards — though older homes may predate them.
Before you start, gather a few simple tools: a flat-head screwdriver or bradawl (for probing timber), a rubber mallet, a spirit level, and a tape measure.
Step 1 — Visual Inspection
Walk around the steps and look carefully at every surface and joint.
- Cracks: Fine surface cracks in concrete are often cosmetic, but wide or stepped cracks (especially diagonal ones) can indicate movement or subsidence. In masonry, look for cracks running through mortar joints or through the blocks themselves.
- Spalling and deterioration: Flaking or crumbling concrete surfaces reduce slip resistance and expose the reinforcing steel beneath to rust.
- Rot and decay: On timber steps, look for dark discolouration, soft spots, or fungal growth — especially where timber meets the ground or a concrete footing.
- Rust staining: Orange streaks on concrete can mean the internal steel reinforcing is corroding and expanding, which will eventually cause the concrete to crack and fail.
- Settlement: Check whether the steps have tilted, sunk, or pulled away from the house. A gap between the steps and the wall cladding is a common sign.
Step 2 — Physical Testing
Once you've looked, it's time to feel.
- Probe timber with a screwdriver: Push the tip firmly into the wood at joints, the base of stringers (the side supports), and any area that looks discoloured. Healthy timber is firm; rotted timber will give way easily.
- Tap concrete with a mallet: A solid, dull thud is good. A hollow sound suggests delamination — layers of concrete separating internally — which weakens the structure significantly.
- Apply body weight carefully: Stand on each tread and shift your weight. Any flex, bounce, or movement in a concrete or masonry step is a red flag. Timber steps have some natural flex, but excessive movement or creaking at the fixings warrants investigation.
- Check the handrail: Grab the handrail and push and pull firmly in all directions. Under the NZ Building Code Clause D1, handrails on steps with a fall risk must be secure and able to withstand a reasonable lateral load. A wobbly handrail is both a code issue and a safety hazard.
Step 3 — Check Dimensions and Slip Resistance
Use your tape measure and spirit level to check:
- Riser height: Should be consistent across all steps, typically between 100 mm and 190 mm under NZ Building Code requirements.
- Tread depth (going): Typically a minimum of 240 mm for exterior steps.
- Level: Treads should slope very slightly forward (around 1–2%) to shed water, but should not be noticeably tilted side to side.
- Slip resistance: Smooth concrete, painted timber, or worn tile surfaces can become dangerously slippery when wet — a real concern in New Zealand's often damp conditions. Look for anti-slip nosings, grit strips, or textured surfaces.
For detailed guidance on access route requirements, MBIE Building Performance publishes the NZ Building Code and acceptable solutions.
Step 4 — Inspect the Foundation and Surroundings
Steps don't fail in isolation. Check:
- Footings: Are the steps sitting on a concrete pad or footing, or directly on soil? Steps resting on bare ground are prone to movement as the soil shifts with moisture changes.
- Drainage: Water pooling around the base of steps accelerates deterioration in all materials. Check that the ground slopes away and that there are no blocked drains nearby.
- Connections to the house: Where steps attach to the house framing or foundation wall, look for rust on fixings, gaps in caulking, or signs of moisture ingress. This area is covered under NZ Building Code Clause E2 (External Moisture).
BRANZ has useful technical resources on moisture management and building envelope performance that can help you understand what you're seeing.
Common Warning Signs at a Glance
| Warning Sign | Likely Issue | Urgency |
|---|---|---|
| Wide or stepped cracks in concrete | Subsidence or structural movement | High |
| Hollow sound when tapped | Delamination | Medium–High |
| Soft or spongy timber | Rot or decay | High |
| Wobbly handrail | Fixing failure, code non-compliance | High |
| Steps pulling away from house | Settlement or fixing failure | High |
| Slippery surface | Slip hazard, especially when wet | Medium |
| Rust staining on concrete | Corroding reinforcing steel | Medium–High |
Do You Need a Building Consent?
Replacing or repairing steps may or may not require a building consent, depending on the scope of work. Minor like-for-like repairs are often exempt under Schedule 1 of the Building Act 2004, but replacing the entire structure or changing the design may require consent. Always check with your local council before starting significant work — requirements vary by region and the specifics of your project. You can find general guidance at MBIE Building Performance.
When to Call a Professional
A DIY inspection is a great starting point, but some situations call for expert eyes:
- You find significant cracking, settlement, or movement and aren't sure of the cause.
- Timber rot extends into the structural stringers or the connection to the house framing.
- The steps are attached to a deck or elevated structure — this involves NZS 3604 framing considerations.
- You're buying or selling a home and need a formal report.
- You want peace of mind before carrying out repairs.
A Licensed Building Practitioner (LBP) or a qualified building inspector can carry out a thorough assessment and advise on the best course of action. You can find experienced local building inspectors on tradedirectory.co.nz. For LBP information, visit Licensed Building Practitioners.
Safety note: If steps feel seriously unstable or unsafe, restrict access immediately — use barrier tape or a temporary barrier — until they can be properly assessed and repaired.
Licensed Building Practitioner (LBP)
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