Most homeowners have never heard of a wall tie until a surveyor's report or a mortgage valuation mentions one. In 2026, replacing the ties to a single affected elevation on an ordinary 3-bed semi typically costs £600–£1,200, working out at roughly £5–£8 per individual tie or £30–£50 per square metre of wall treated. Where a survey finds corrosion has spread beyond one wall, full replacement across the whole house runs to £1,300–£2,700 on a 3-bed semi, and £2,000–£4,000 or more on a larger detached property. A specialist borescope survey to establish which of those you've actually got, before any remedial work is agreed, costs £200–£450.
Wall ties are the metal fixings buried in the mortar joints that tie the outer leaf of brickwork to the inner leaf across the cavity, holding the outer skin upright rather than letting it stand as a free-standing wall of its own. Most houses built between the 1920s and the 1980s used plain wire, fish-tail or butterfly ties in mild steel, often with a coating thin enough to fail well within the life of the house. Once a tie starts rusting it doesn't just weaken — it expands, and that expansion is what does the visible damage: cracking, bulging, and eventually a genuine loss of restraint to the outer wall.
I don't replace wall ties myself — that's a specialist contractor's job, done with resin-fixed or mechanically-expanded remedial ties driven into sound masonry from outside. What I do, when I find suspect cracking or bulging during a building survey, is diagnose it: a metal detector to locate the existing ties, a small hole drilled into a mortar joint, and a borescope through the hole to look at what's actually happening in the cavity before anyone's quoted for a fix. It's a cheap, quick way to turn a guess into an answer, and it's exactly the diagnostic step a lot of the more alarming quotes I see skip straight past.
The short answer
Figures below were checked on 22 September 2026 against Checkatrade's own wall tie cost guide and CavClear, a UK cavity wall remediation specialist, cross-referenced against TrustATrader's trade-sourced figures and a specialist borescope inspection guide for the survey cost. As with most trades in this series, the South East trends toward the top of these ranges, and access — whether the work can be done from ground level or needs a scaffold to the upper storeys — moves the price more than almost anything else.
| Job | Typical cost (2026) | What's included |
|---|---|---|
| Wall tie survey (borescope inspection) | £200–£450 | Locating and inspecting existing ties before any remedial work is agreed |
| Targeted replacement, one elevation | £600–£1,200 | New remedial ties to the affected wall run only, on an ordinary semi |
| Full replacement, 3-bed semi | £1,300–£2,700 | All affected elevations, once a survey finds corrosion has spread |
| Full replacement, larger or detached house | £2,000–£4,000+ | Scales with wall area — get it priced per elevation, not as one lump sum |
Priced per unit rather than by property, that's roughly £5–£8 per remedial tie fitted, or £30–£50 per square metre of wall treated once labour, access and making good are folded in. On a typical semi elevation of around 25–30m², that puts a single-wall job comfortably within the £600–£1,200 figure above; scale that per-metre rate up across every elevation of the house and you land in the £1,300–£2,700 range for a full 3-bed semi, which is also roughly what Checkatrade's own worked example for a 3-bed semi comes out at. There's no dedicated grant for this work in 2026 — it doesn't fall under ECO4, GBIS or the Boiler Upgrade Scheme, whatever a sales quote might otherwise imply.
What drives the price
Age and original tie type. Houses built from the 1920s through to the 1980s are the age bracket most commonly affected, because wire, fish-tail and butterfly ties from that era often lacked the corrosion resistance modern galvanised or stainless ties are made to. The older and thinner the original coating, the sooner failure tends to show.
Extent of corrosion. This is the single biggest swing factor, and the reason the survey matters more than the quote. A house with one exposed, weather-facing elevation failing while the rest are sound is a different, cheaper job than one where the same ties were used throughout and have all reached the same point in their working life.
Method. Most contractors now use resin-fixed stainless steel remedial ties, which anchor into sound masonry with a chemical resin rather than relying on mechanical expansion alone — the safer choice in older or softer brick and stone. Helical ties, screwed rather than resin-fixed, are sometimes used instead and can work out marginally cheaper on straightforward brick.
Access. Ground-floor walls are straightforward. Anything above requires a scaffold tower or full scaffold — see my scaffolding cost guide for what that adds on its own account, since it's rarely included in a headline wall-tie quote.
Cavity insulation. If the cavity has already been filled — see my cavity wall insulation cost guide — a borescope survey may not be able to see past the insulation to inspect every tie properly, which can mean either a more limited inspection or, in some cases, partial removal of insulation to check thoroughly. Worth asking about specifically if your cavity was filled some years ago.
Making good. Drilled inspection holes and the small holes needed to fit remedial ties are made good in mortar colour-matched to the existing brickwork, usually included in the quote; render or cladding removal and reinstatement, where present, is priced separately and adds meaningfully to the job.
How it's actually diagnosed
The tell is usually the pattern, not a single crack. Corroding wall ties rust and expand, and that expansion tends to crack the mortar joint horizontally at roughly six-brick-course intervals — the spacing ties are typically installed at, around 450mm vertically. As the outer leaf is pushed outward by that expansion, the same wall can develop a subtle bulge or ripple, visible from a low, raking angle along the elevation rather than face-on. Neither sign on its own confirms wall tie failure; both can also be caused by other forms of movement entirely, which is where a chartered surveyor's or structural engineer's judgement on the wider pattern of cracking earns its keep.
Confirming it properly means locating the ties first — typically with a metal detector run along the wall to find the metal within the mortar joints — then drilling a small 10–12mm hole into a mortar joint, never the brick face, at one or more of those points, and passing a borescope through to look directly at the tie's condition. It's a cheap, non-destructive step (my borescope guide covers the kit end of this) and it's the difference between a specialist telling you "this elevation needs doing" from genuine evidence, and a five-minute look at one visible crack turning into a five-figure whole-house quote. I'd want to see the survey findings, ideally with photographs from the borescope, before agreeing to any scope of remedial work at all.
The proportionate question that follows is whether the whole house needs doing or just the wall that's showing symptoms. Where one elevation faces the prevailing weather and the others don't, isolated failure on that wall alone is a genuine and common outcome, and treating it in isolation is a fair repair rather than a false economy. Where the same wire ties were used throughout the build and one wall has already failed, the sensible assumption is that the others are on a similar clock even if they're not showing symptoms yet — and a specialist's survey, not a guess from either side, is what should settle which situation applies.
What I'd watch for in a quote
- An independent survey before a quote, not instead of one. A firm that goes straight from "I can see a crack" to a full-house price, without a borescope survey establishing the actual extent, is asking you to buy on assumption.
- Remedial ties to BS EN 845-1. This is the current British Standard for ancillary components for masonry, covering the specification remedial wall ties should meet. A written quote that names the tie type and standard is worth more than one that just says "new wall ties."
- Resin-fixed ties in soft or friable masonry. Purely mechanical expansion ties can work loose in softer brick or older lime mortar; resin fixing is the more reliable choice on anything but sound, hard modern brick.
- Per-metre or per-tie pricing broken down on the written quote, not a single lump figure, so you can see what you're paying for and compare quotes on the same basis.
- An insurance-backed guarantee that survives the firm folding, the same as I'd look for on any structural remedial work.
Questions I get asked
How much does wall tie replacement cost? In 2026, targeted replacement to a single affected elevation on an ordinary semi typically costs £600–£1,200, at roughly £5–£8 per tie or £30–£50 per square metre. Full replacement across the whole house runs £1,300–£2,700 on a 3-bed semi, and £2,000–£4,000 or more on a larger detached property. A borescope survey to establish the extent first costs £200–£450.
How do I know if my wall ties have failed? The classic sign is horizontal cracking in the mortar joints, usually repeating roughly every six brick courses, which is where the ties sit. A corroding tie rusts and expands, which can also push the outer leaf outward into a subtle bulge or ripple visible from a low angle. Neither confirms it alone — a metal detector to locate the ties, followed by a borescope through a small drilled hole, is what actually confirms wall tie failure.
Do I need to replace all my wall ties, or just some? It depends on what the survey finds, which is why I wouldn't agree to a whole-house quote on the strength of one cracked wall. Corrosion confined to one exposed elevation can be a genuine, proportionate repair on its own. Where the same ties were used throughout and one wall has already failed, the others are usually on a similar clock, and a specialist's survey should establish which situation actually applies before you commit to either scope.
Is wall tie replacement covered by home insurance? Generally not. It's treated as wear and tear or a maintenance issue rather than sudden accidental damage, which is what most buildings policies are written to cover. Where corrosion has caused genuine structural movement, an insurer may get involved via a subsidence-style claim, but that's the exception rather than the rule — check your policy wording rather than assuming either way.
If a survey's flagged suspect cracking or bulging and you'd like an independent read on whether it's wall ties, and how far it's actually spread, before anyone quotes for the fix, that's exactly what my building survey work is for — and where the pattern of movement points to something beyond a straightforward tie replacement, I'll say so and refer you to a structural engineer rather than let a diagnosis run past what a borescope can tell you. Call 07946 618203 or get in touch and I'll give you a straight answer before you spend the money.
Small print. This guide is general information, not advice on a specific property, and it doesn’t replace a proper survey and quote for your own home. Prices were researched and correct to the best of my knowledge on 22 September 2026; costs move and vary by region and property. Always get at least three written quotes, and get an independent survey before agreeing to any remedial wall tie work.