Replacing a single broken terracotta ridge tile is technically within reach for a capable DIYer — it doesn't require a building consent and isn't restricted work under the NZ Building Code. However, the biggest challenge isn't the tile itself; it's working safely at height on a sloped roof. Before you grab a ladder, read this guide carefully.
Understanding the Risks of Working at Height
Ridge tiles sit at the very peak of your roof, making them the most exposed and hardest-to-reach tiles on the building. Falls from roofs are one of the leading causes of serious injury and death in New Zealand. WorkSafe NZ has strict guidelines around working at height, and even though these are primarily aimed at tradespeople, the same hazards apply to homeowners.
Before you go anywhere near the roof:
- Never work alone — always have someone on the ground.
- Use a roof ladder (one with a ridge hook) to spread your weight and avoid slipping.
- Wear non-slip footwear and consider a safety harness anchored to a suitable point.
- Check the weather — avoid working on wet, frosty, or windy days.
- Inspect the roof from the ground first using binoculars to assess the damage.
If your roof pitch is steep (generally above 25–30°), or if you're not comfortable with heights, this is a job best left to a professional.
What You'll Need
Gather your materials and tools before climbing:
| Item | Notes |
|---|---|
| Replacement terracotta ridge tile | Match profile, colour, and size to existing tiles |
| Roofing mortar or flexible ridge bedding compound | See below for product options |
| Cold chisel and hammer | For removing old mortar |
| Stiff brush | To clean the ridge |
| Pointing trowel | For applying new mortar |
| Roof ladder and standard ladder | Essential for safe access |
| Safety harness (recommended) | Anchor to a suitable roof anchor point |
Finding a matching tile can be the trickiest part. Terracotta ridge tile profiles vary by manufacturer and era. Take a photo and a measurement of the broken tile to a roofing supplier or a store like Bunnings or Mitre 10. For older or heritage tiles, you may need a specialist roofing supplier or salvage yard.
Choosing the Right Mortar
Traditional ridge tiles were bedded in a sand-and-cement mortar mix, but this can crack over time due to thermal movement — a common issue in New Zealand's variable climate. Modern best practice often favours a flexible ridge bedding system or a polymer-modified mortar, which handles movement better.
Products from Sika or Ardex include flexible roofing and bedding compounds suitable for this application — check their product guides for what's appropriate for terracotta and your specific conditions. Always follow the manufacturer's instructions for mixing ratios and cure times.
Step-by-Step: Replacing the Ridge Tile
1. Remove the broken tile and old mortar
Carefully lift away any loose pieces of the broken tile. Use a cold chisel and hammer to chip away the old mortar from the ridge board or the surrounding tiles. Work gently to avoid disturbing neighbouring tiles. Brush the area clean.
2. Check the ridge board and underlayment
While you're up there, inspect the timber ridge board for rot or damage, and check that the roofing underlay beneath is intact. If you spot rot or torn underlay, the scope of work increases — consider calling a roofer at this point.
3. Dry-fit the new tile
Place the new ridge tile in position without mortar first to confirm it fits correctly and aligns with the surrounding tiles.
4. Bed the tile in mortar
Mix or prepare your bedding compound per the manufacturer's instructions. Apply a generous, even bed of mortar to the seating area on both sides of the ridge. Press the new tile firmly into place, checking it's level and aligned. Remove any excess mortar that squeezes out.
5. Point the joints
Neatly finish the mortar joints at each end of the tile with your trowel, ensuring there are no gaps where water can enter. A smooth, slightly angled finish helps shed water.
6. Allow to cure
Keep foot traffic off the area and protect from rain if possible while the mortar cures — check the product datasheet for cure times.
Does This Need a Building Consent?
Replacing a like-for-like broken ridge tile is generally considered routine maintenance and falls under Schedule 1 of the Building Act 2004 as exempt work — meaning no building consent is required. However, exemptions have conditions, and rules can vary. Always confirm with your local council before starting work. You can find guidance at MBIE Building Performance.
When to Call a Professional
Call a licensed roofer if:
- You're not confident working at height or your roof pitch is steep.
- Multiple ridge tiles are damaged or the ridge mortar is failing along a large section.
- You find rot in the ridge board or damage to the roofing underlay.
- You can't find a matching replacement tile.
- The roof is fragile, old, or made of materials you're unfamiliar with.
A qualified roofer will have the right equipment, experience, and insurance to do the job safely and correctly. You can find trusted local roofing professionals on tradedirectory.co.nz.