How to Price Structural Repairs: Crack Stitching, Lintel Replacement and Repointing

Quick Answer: UK structural repair pricing in 2026 covers a wide range: crack stitching with helical bars £80–£180/m of crack, lintel replacement £400–£1,400 per opening (catnic/concrete to brick over door/window), pad foundation underpinning £900–£2,500/m run, mass concrete underpinning £600–£1,800/m run, and structural repointing of distressed brickwork £75–£140/m². A structural engineer's report (essential before any repair work) costs £400–£1,200 typical. The cost of remedial work is dwarfed by the cost of getting the diagnosis right — repairs without a structural engineer's specification typically waste 20–50% of the budget on the wrong fix, and may invalidate the property's insurance and resale.

Summary

Structural repair work is the area where pricing accuracy matters most because the cost of a wrong repair is much higher than the cost of getting a structural engineer involved. A typical pattern: customer notices a crack, gets a builder to "fix it", builder injects mortar or fits a steel plate, three years later the crack reappears bigger because the underlying movement was never diagnosed or addressed. Cost to repair: £600 first time, £4,500 second time including the engineer that should have been involved at the start.

The pricing framework that holds together is sequential: diagnosis (engineer's report) → specification → pricing → execution → monitoring. Every structural repair quote should reference an engineer's specification, even if it's just a single-page letter. A quote that proposes structural work without engineer involvement should be a red flag for the customer; a builder quoting it without an engineer should expect to take on full liability for the diagnosis.

The other thing customers don't usually understand is that structural repair is rarely "fix the crack" — the crack is a symptom. The repair must address the cause: subsidence from a clay shrinkage, drainage washing out fines, lintel failure, wall tie corrosion, thermal expansion, foundation settlement. Each cause has a different repair specification, and the price difference between them is significant.

Key Facts

• Structural engineer's report — £400–£1,200 typical for a domestic single-issue assessment
• Helical bar crack stitching — £80–£180/m of crack stitched (Helifix or similar)
• Resin grout crack repair — £45–£90/m for thin cracks (<3mm), polymer-modified resin
• Wall tie replacement — £8–£18 per tie installed (typically 4–9 ties/m² of wall)
• Lintel replacement (catnic over door) — £400–£900 per lintel
• Lintel replacement (RSJ for opening with brick over) — £900–£2,800 depending on span
• Mass concrete underpinning — £600–£1,800/m run
• Pad foundation underpinning — £900–£2,500/m run
• Pile underpinning (mini piles) — £1,200–£3,500/m run
• Cement injection / void grouting — £350–£900 per void filled
• Repointing structural (lime mortar on solid wall) — £75–£140/m²
• Brick replacement (matched, including cutting out) — £15–£40 per brick
• Tree root removal — £250–£800 per tree depending on access
• Drainage repair (root-related crack to drain) — £900–£3,500 (often relined £1,500–£3,500)
• Chimney rebuilding (above eaves) — £1,200–£4,500 plus scaffold £600–£1,800
• Subsidence movement monitoring — £150–£300 per monitoring visit (typically 6+ visits over 12 months)
• Schedule of conditions report — £400–£900 per property (Party Wall preliminary)
• Building insurance subsidence claim — typical excess — £1,000–£2,500 (specific subsidence excess)

Quick Reference Table — Structural Repair by Type

Detailed Guidance

Why a structural engineer is essential

The one rule that holds: never quote or carry out structural repair without a written specification from a structural engineer (Chartered, MIStructE or equivalent).

Reasons:

• Diagnosis — the cause of the crack/movement determines the right repair
• Specification — bar sizes, resin types, depth, spacing, materials all must be specified
• Sign-off — Building Regulations approval requires engineer's calcs for load-bearing changes
• Insurance — claims fail without structural engineer involvement
• Resale — buyers' surveyors flag structural issues; documented repair is acceptable, undocumented is a deal-breaker

A structural engineer's report typically costs £400–£1,200. For a £15,000 underpinning job, that's 3–8% of the total. For a £900 crack repair, it's a higher percentage but still cheaper than the cost of a wrong repair.

Crack stitching — when it works

Helical bar stitching (Helifix Crackstitch, Twistfix, Concrete Repairs Ltd):

• Helical stainless steel bar (typically 6mm dia × 1m length)
• Slot cut into mortar bed across the crack
• Polymer grout bonds bar into slot
• Bar reinforces the wall at that horizontal plane

Used for:

• Stepped cracks in cavity wall above lintel
• Settlement cracks in solid wall
• Cracks where movement has stabilised

Not suitable for:

• Active movement (must stabilise cause first)
• Cracks indicating foundation failure
• Through-cracks with offset (need underpinning + stitching)

Cost: £80–£180/m of crack, including bars, slot-cutting, grout, repointing.

Lintel replacement — common but mis-priced

Failed lintel symptoms:

• Sagging brickwork above door or window
• Cracking radiating up and out from corners of opening
• Door or window jammed/binding

Typical replacement:

• Prop the opening (acrow props + needles)
• Cut out failing lintel
• Insert new catnic (steel pre-formed) or concrete lintel + cavity tray
• Bed in mortar, point up
• Re-lay any disturbed brickwork

Cost factors:

• Span (cost rises with span — beyond 1.5m starts needing structural design)
• Cavity vs solid wall
• Internal lintel only or external + internal
• Whether existing brickwork above can be retained or needs replacement
• Whether scaffold/access platform required

Range: £400–£900 for a standard single-opening replacement. Up to £2,800 for a longer-span or compound (cavity tray, weep vents, full reinstate) job.

Underpinning — when there's no alternative

Underpinning is the structural repair customers fear most because of cost. It's typically £6,000–£20,000+ for a typical UK domestic property.

When underpinning is required:

• Active subsidence movement (proven by monitoring)
• Foundation settlement causing structural distress
• Tree-related subsidence where tree retention is required (listed tree, neighbouring property)
• Drainage washout that has undermined existing foundations

Methods:

• Mass concrete — traditional, sequential excavation in 1m bays, fill with concrete. £600–£1,800/m run.
• Mini-piled (e.g. screw piles, segmental piles) — used where vibration must be minimised or access is poor. £1,200–£3,500/m run.
• Pad and beam — pile-supported beams under existing foundation. £900–£2,500/m run.
• Resin injection (URETEK, Geobear) — non-excavation alternative, polymer expansion compacts ground. £4,000–£15,000 typical.

The cause of subsidence must be addressed before or as part of the underpinning. Tree removal, drain repair, soakaway construction often go alongside.

Wall tie replacement — easily misdiagnosed

Cavity wall ties (galvanised steel, 1930s–1980s) corrode over time. As they corrode, they expand, cracking the mortar joint, and progressively lose structural connection between inner and outer leaves of the cavity wall. Symptoms:

• Horizontal cracking along mortar joints at regular intervals (typically 6 courses up = 450mm)
• Outer leaf bulging or leaning
• Vertical cracking at corners

Repair:

• Mechanical or chemical replacement of corroded ties
• Stainless steel helical wall ties driven into pre-drilled holes through both leaves
• Typically 4–9 ties/m² of wall area

Cost: £8–£18 per tie, plus £400–£800 setup per elevation. A typical cavity-wall front elevation (60–80m²) requires 240–720 ties = £2,000–£12,000+.

Drainage and trees — the underlying causes

Many domestic structural problems stem from:

• Tree roots drying out clay soil under foundation (subsidence)
• Failed drains washing out fines from beneath foundation (washout settlement)
• Damaged drainage allowing localised saturation and clay heave (heave damage)

Always investigate underlying causes before specifying foundation repair:

• CCTV survey of drains (£120–£280)
• Tree survey (£250–£500 for arborist's report)
• Soil investigation (window-sample borehole £600–£1,500)

These investigations are inexpensive compared to misdiagnosed underpinning.

Insurance and structural work

Most home insurance policies cover subsidence with a high specific excess (£1,000–£2,500) and require:

• Structural engineer's report
• Evidence of monitoring
• Cause identification
• Full repair specification

Process: report damage to insurer, insurer instructs structural engineer (or accepts customer's), monitoring period of 6–12 months, repair specification, contractor selected, work carried out and signed off. Total timeline 12–24 months for full subsidence claim.

Customers often want to "just fix it" without insurance involvement; this is fine for non-subsidence work but means missing out on cover for the work. Always advise the customer to engage their insurer before starting structural repair.

Frequently Asked Questions

When is a crack a structural problem?

A crack wider than 5mm at any point, a stepped crack that crosses 3+ brick courses, an active crack that reopens after pointing, or any crack with associated distortion (window/door not closing, floor sloping). Hairline cracks (<1mm) are usually cosmetic — settlement or thermal movement.

Do I need a structural engineer for crack repair?

For any non-cosmetic crack, yes. A £400–£1,200 engineer's report saves £4,500+ in misdiagnosed repair work. The engineer will assess movement, classify cause, and specify repair.

How much does a typical underpinning job cost?

UK average: £8,000–£20,000 for a single elevation of underpinning. Full perimeter: £25,000–£60,000. Cost varies hugely with method, depth, ground conditions, access.

Will my insurance cover structural repair?

Subsidence damage typically yes (with high excess and long process). Other structural damage (lintel failure, wall tie corrosion) may or may not be covered depending on policy wording — usually treated as wear and tear and excluded.

How long does monitoring take before underpinning?

Typically 6–12 months of monthly monitoring. Building Insurance Companies (BICs) and the Royal Institute of Chartered Surveyors (RICS) recommend at least 6 months' monitoring data before specifying structural intervention.

Regulations & Standards

• Building Regulations Approved Document A — structural safety; load calculations for any structural alteration

• Building Regulations Approved Document C — site preparation and resistance to moisture

• Party Wall etc. Act 1996 — applies when underpinning, excavating near boundaries, or supporting party walls

• BS 5628 series — code of practice for the use of masonry (legacy, partially superseded)

• BS EN 1990:2002+A1:2005 — Eurocode: basis of structural design

• BS EN 1996-1-1 — Eurocode 6: design of masonry structures

• BS 5930:2015+A1:2020 — code of practice for ground investigations

• BS 8004:2015 — code of practice for foundations

• BRE Digest 251 — assessment of damage in low-rise buildings (categorisation of crack severity)

• BRE Digest 298 — the influence of trees on house foundations in clay soils

• CDM Regulations 2015 — duties on structural construction work

• Institution of Structural Engineers (IStructE) — UK chartered body for structural engineers

• Building Research Establishment (BRE) Digests — UK technical guidance for damage assessment

• Helifix Technical Library — crack stitching and wall tie technical data

• Subsidence Forum — UK industry body for subsidence work

• The Geological Society — Subsidence — UK ground investigation guidance

• repointing pricing for structural masonry

• wall crack diagnosis: structural vs cosmetic

• drain repair pricing for drainage-cause subsidence

• building regulations process for structural alterations

• building control sign-off for underpinning and structural repair