Ask These 8 Things Before Committing to Wall Tie Replacement in Your Sydney Heritage Home

A bulge in your brickwork or a jagged horizontal crack might look like simple weathering, but it’s often the first visible sign of cavity wall tie failure – a structural problem that won’t fix itself and tends to accelerate once it starts. Cavity wall tie failure happens when the metal ties holding your inner and outer brick walls together corrode and lose their strength, allowing the outer leaf to pull away from the structure. In Sydney’s coastal and harbourside suburbs, salt air speeds up corrosion in older galvanised ties, and by the time cracks appear, the damage is already advanced. The good news: the fix doesn’t require tearing down walls, but it does require the right contractor asking the right questions before they start drilling.

1. Can You Show Me Evidence the Ties Have Actually Failed?

Not every crack means your wall ties are gone. Settling, minor movement, or poor pointing can all produce hairline cracks that look alarming but don’t signal structural failure. A contractor worth hiring will explain the difference and show you why they believe the ties – not something else – are the problem.

Ask them to point out the telltale signs: horizontal cracking that follows the mortar bed joints (not random diagonal cracks), outward bowing or bulging you can see in profile, and any separation you can measure between the inner and outer walls. In Sydney’s Federation and interwar brick homes, these symptoms often appear first on exposed elevations – the south-facing wall that cops the weather, or the harbour-side facade that gets salt spray year-round.

A proper assessment includes checking multiple walls, not just the one that cracked. Corrosion rarely stops at a single elevation, so if ties have failed on the street-facing wall, the side and rear walls are likely candidates too. If the contractor only looks at the crack you showed them and quotes immediately, they’re guessing, not diagnosing.

2. What Type of Ties Will You Install, and Why?

The ties that failed were almost certainly galvanised mild steel – the standard in Australian masonry from earlier decades. They rust from the inside out, and by the time you see the damage, the tie has lost most of its cross-section. Replacing them with the same material just resets the clock for further slow corrosion.

The modern fix uses stainless steel remedial ties, typically helical or mechanical ties that drill into the existing mortar joints and lock both leaves together without major disturbance. These don’t corrode in salt air, which matters in Sydney’s eastern suburbs, lower north shore, and any property within a few kilometres of the coast or harbour. A contractor who suggests galvanised replacements either doesn’t understand the problem or is offering the cheapest option without telling you the trade-off.

Ask what grade of stainless steel they specify – 316 marine grade is the standard for exposed coastal locations, 304 is acceptable inland. And ask how the ties are fixed: mechanical expansion, resin anchoring, or helical drilling all work, but each suits different wall conditions and brick types. A heritage terrace with soft lime mortar needs a gentler fixing method than a later cavity brick veneer.

3. How Will You Match the Mortar and Make Good the Drill Holes?

This is where heritage restoration separates from structural patching. Installing new ties means drilling into the mortar joints at regular intervals across the affected walls – that’s a lot of holes, and every one of them has to be filled and pointed to match the original work.

On a Federation terrace or an interwar apartment block, that original mortar is almost always a lime-based mix, not the grey cement mortar used in modern building. Lime mortar is softer, more vapour-permeable, and a completely different colour and texture. If the contractor fills the drill holes with a cement-based pointing mortar, you’ll see a grid of grey dots across your brickwork forever, and the mismatch can actually trap moisture and damage the surrounding masonry.

Ask to see samples of their mortar mixes, or better yet, ask if they’ll send a sample of your existing mortar for laboratory analysis before they start. A heritage specialist will match not just the colour but the binder type, sand grading, and texture so the repair disappears into the original work. They should also explain how they’ll clean up: drilling into old brickwork produces dust, fragments, and staining that needs careful removal, not a pressure washer that blows out more mortar.

4. How Many Ties Will You Install, and Where?

Masonry standards specify wall tie spacing based on wall height, exposure, and loading. A typical requirement is appropriate spacing for wall area. On a two-storey terrace facade, you’re looking at many ties on the street-facing wall alone.

A contractor who quotes an insufficient number of ties for a house that clearly needs more is either underestimating the job or planning to install the minimum number they think they can get away with. Either way, the wall won’t be properly supported, and the cracking will return. Ask them to explain their tie layout and spacing, and ask if they’ll provide a marked-up elevation drawing showing where each tie goes. If they can’t or won’t, they’re winging it.

You should also ask about edge distances and openings: ties can’t be placed too close to door and window reveals, and they need to avoid services like electrical conduits or plumbing penetrations. A contractor who’s done this before will spot these constraints during the site visit and build them into their quote. One who hasn’t will discover them halfway through the job and either skip those areas or ask for more time and money.

5. Will You Provide a Fixed-Price Contract Under NSW Fair Trading Rules?

Wall tie replacement jobs in Sydney typically run well over the $5,000 threshold that triggers NSW Fair Trading contract requirements. That means the contractor is legally required to provide a written contract, a fixed scope of work, and a breakdown of what’s included. If they’re quoting a per-tie rate with no upper limit, or if they’re vague about what “making good” actually covers, you have no protection when the job grows.

Ask for a contract that specifies the total number of ties, the mortar type and matching method, the access arrangements (scaffold or working from ground level), and whether repointing around the tie locations is included or extra. Jobs over $20,000 also require the contractor to provide Home Warranty Insurance – if they don’t mention it, they’re either unlicensed or trying to keep the quoted price just under the threshold by leaving work out.

A proper contract also locks in your payment schedule. NSW Fair Trading limits deposits to 10% of the contract price for jobs under $20,000, and requires progress payments tied to completed stages for larger jobs. A contractor who asks for half the money upfront before they start is breaching the rules, and paying them puts you outside the protections the legislation provides. You can read the full requirements on the NSW Fair Trading housing and building page.

6. How Will You Access the Wall, and What’s Included?

A ground-floor wall on a single-storey building is straightforward: ladders or low scaffold, no complications. A two-storey Federation terrace with a tall facade and no setback from the street is a different job entirely. Full scaffold hire, traffic management, and safe working platforms can add considerably to the job cost, and contractors price it differently – some include it, some quote it separately, and some leave it out entirely and expect you to arrange access yourself.

Ask upfront whether scaffold or elevated work platform hire is included in the quote. Ask who arranges council permits if scaffold has to go on the footpath. Ask whether the contractor is licensed to erect their own scaffold or whether they subcontract it, and if subcontracted, whether that cost is locked in or provisional. A contractor who says “we’ll sort that out when we start” hasn’t priced the job properly, and you’ll be the one paying the difference.

For heritage buildings in tightly packed terraces – common across Paddington, Glebe, Newtown, and Balmain – you may also need to notify adjoining owners, arrange party wall access, or work around strata common property rules. These aren’t the contractor’s problems to solve, but a contractor who’s worked in these areas before will flag them during the site visit instead of discovering them on day one of the job.

7. Will You Repoint the Surrounding Brickwork, or Just the Tie Holes?

Drilling and installing new ties disturbs the mortar around each fixing point, and in older masonry, that mortar is often already fragile. A contractor who only fills the drill holes and leaves the surrounding joints cracked or hollow is leaving the job half-finished. The wall might be structurally sound again, but it will still look damaged, and water will still get in through the open joints.

Ask whether the quote includes repointing the affected areas – not the whole building, but at least the mortar bed joints where the ties were installed and any adjacent joints that are loose or missing. On a heritage building, this is where the job crosses from structural repair into restoration: the repointing has to match the original mortar in colour, texture, and profile, and it has to be done by hand with the right tools and technique. Poor repointing is immediately obvious on a Federation terrace and can actually reduce the property’s value.

If the contractor is offering tie replacement without any repointing at all, they’re either pricing themselves cheap to win the job or they don’t understand that the work is interconnected. Either way, you’ll be calling someone else back to finish the job properly, and the second contractor will charge considerably to repoint the wall. You can learn more about what proper heritage repointing involves on the NSW Heritage Council website.

8. What Happens If You Find More Damage Once You Start?

Wall tie failure rarely exists in isolation. Corroded ties are a symptom of water getting into the cavity, and that same water has been attacking the mortar, the brick faces, and any lintels or structural steel in the wall. Once the contractor opens up the joints and starts drilling, they may find spalled bricks, damaged lintels, or sections of wall that are barely holding together.

Ask how they handle variations: will they stop work and get your approval before proceeding, or will they patch what they find and present you with a bigger bill at the end? A professional contractor will document additional damage with photos, explain what needs to be done and why, and give you a written variation quote before they do the extra work. One who doesn’t is either hoping you won’t notice the extra charges or planning to walk away if you refuse to pay them.

This is also where a detailed site inspection before quoting proves its value. A contractor who climbs a ladder, taps the wall with a hammer, and checks a few joints before quoting is less likely to be surprised by hidden damage than one who quotes from the footpath. Surprises mid-job cost time and money, and most of that cost lands on you.

9. Can You Provide References for Similar Heritage Projects?

Wall tie replacement is a structural repair, but on a heritage building it’s also conservation work. The techniques, materials, and finish standards are different from modern construction, and not every bricklayer or builder has the experience to get it right. A contractor who specialises in heritage masonry will have a portfolio of completed projects they can show you – not just before-and-after photos, but details of mortar mixes, tie installations, and brick matching.

Ask to see examples of their work on Federation terraces, interwar apartment blocks, or other buildings of similar age and construction to yours. Ask if they can provide contact details for previous clients – not as a formal reference check, but so you can ask how the job went, whether the contractor turned up when promised, and whether the finished work matched what was quoted. A contractor who’s confident in their work will hand over references without hesitation.

You should also ask about their builders licence and whether it covers structural repair work. In NSW, wall tie replacement is considered structural work and requires an appropriate licence class, not just a general building licence. A contractor working without the right licence isn’t insured for structural claims, and if something goes wrong, you have no recourse through Home Warranty Insurance.

10. How Long Will the Job Take, and What Disruption Should I Expect?

Wall tie replacement is not a fast job. Drilling, cleaning, installing ties, and making good the mortar is repetitive, detail-focused work, and rushing it produces poor results. A typical project can take time depending on access, weather, and the condition of the existing masonry.

Ask for a realistic timeframe and a schedule that accounts for scaffold erection and removal, material deliveries, and mortar curing times. Ask whether they’ll work continuously or whether they’re juggling multiple jobs and will disappear for days at a time. And ask what disruption you should prepare for: drilling produces noise, dust, and vibration, especially if you’re home during the day.

For occupied buildings, ask whether they can work in stages – completing one elevation at a time so you’re not surrounded by scaffold for extended periods. For strata properties, ask whether they’ll notify neighbours and whether any common property access is needed. These aren’t dealbreakers, but a contractor who’s thought through the logistics of the job is more likely to finish it on time and on budget than one who shows up on day one without a plan.

Ready to Get Your Wall Ties Assessed Properly?

Wall tie failure isn’t something you can fix with a tube of sealant and hope, but it’s also not the catastrophic structural collapse some contractors might imply when they’re trying to close a sale. Done right, with the right materials and the right care for heritage fabric, it’s a permanent fix that stabilises your building and protects it for decades. Done badly, it’s expensive patchwork that looks wrong and fails again later.

Premier Pointing has been stabilising and restoring Sydney’s heritage masonry for over 30 years, and wall tie replacement is one of the structural repairs we specialise in. We assess the full extent of the damage before we quote, we match lime mortars by laboratory analysis, and we install marine-grade stainless ties that won’t corrode in coastal exposures. If your brickwork is cracking, bowing, or pulling away from the building, get in touch for an honest assessment of what needs to be done. You can read more about when to walk away from a failing cavity wall or what to budget for failed wall ties in Sydney heritage brick on our site.

Frequently Asked Questions

What are the signs that a cavity wall tie is failing?

Horizontal cracking along the mortar bed joints is the clearest sign, especially when the cracks run continuously for several metres and follow the same level across the wall. You might also see outward bowing or bulging in the brickwork, damp patches that don’t dry out, or sections of the outer wall that sound hollow when you tap them. On coastal properties or anywhere exposed to salt air, look for rust staining bleeding through the mortar – that’s the corroded tie showing itself from inside the cavity.

Does a cavity wall need wall ties?

Yes. A cavity wall is two separate brick leaves with a gap between them – the outer leaf carries no structural load and would simply fall over without ties connecting it to the inner wall. The ties transfer lateral loads from wind and impact back to the main structure, and they prevent the outer leaf from bowing, leaning, or collapsing. Older buildings used galvanised mild steel ties spaced appropriately; modern practice uses stainless steel ties for longer service life.

Is wall tie failure covered by insurance?

Standard home and contents insurance policies in Australia generally don’t cover gradual deterioration or maintenance issues, and wall tie corrosion falls into that category – it’s a slow process that happens over time, not a sudden insurable event. Some policies may cover the consequential damage if a section of wall actually collapses, but they won’t cover the cost of replacing all the ties as a preventative measure. Check your policy wording and speak to your insurer, but in most cases, wall tie replacement is the owner’s responsibility.

Is replacing wall ties a big job?

It depends on the size of the building and how much of the wall is affected. For a single-storey cottage with one failing wall, it’s manageable work – drill the joints, install new ties, fill and point the holes, clean up. For a two-storey terrace with multiple elevations requiring scaffold and extensive repointing, it’s a bigger project that can take time. The physical work isn’t complicated, but it requires precision, the right materials, and careful making-good to avoid permanent damage to heritage brickwork.

How much does tuckpointing cost in Sydney?

The job depends on wall height, scaffold access, and whether you’re matching heritage mortar or using a standard mix. Tuckpointing is a decorative finish where a coloured base mortar is matched to the brick and then a fine raised putty line is applied by hand – it’s more labour-intensive than plain repointing and requires a specialist who knows the traditional technique. Get a site visit and a fixed quote before committing, and ask to see examples of their previous tuckpointing work to make sure the finish matches what you’re expecting.

What This Means for Cavity Wall Tie Failure

Wall tie failure is one of those problems that looks manageable at first – just a crack, just a bit of movement – and then reveals itself to be extensive once you start investigating. But it’s also a problem with a proven fix, and when that fix is done properly, it’s permanent. The questions above aren’t there to scare you or to make the job seem more complicated than it is; they’re there to help you separate contractors who know what they’re doing from those who are guessing and hoping. Ask them, compare the answers, and choose the contractor who gives you confidence they understand both the structure and the heritage fabric. Your building has stood for a long time – it deserves a repair that will last.