Structural crack expertise in the Alpes-Maritimes and the Var
Cassini Expertise carries out structural crack assessments for owners, buyers, landlords and their advisers across the Alpes-Maritimes (06) and the Var (83). Our mission: identify the origin of the cracks, grade their severity against the recognised classifications, determine the applicable liability regime and recommend repairs suited to the cause.
Independent firm based in Antibes (22 rue Vauban, 06600), we work within the jurisdiction of the Grasse judicial court (competent for Antibes, Cannes, Grasse, Valbonne, Vallauris), and before the Nice, Draguignan and Toulon courts, as well as the Aix-en-Provence Court of Appeal on appeal.
Assessment method: standardised mapping and cause analysis
First phase: documentary and photographic review
Before travelling, we analyse the photographs supplied by the client, the building plans (planning permission, as-built drawings, a G2 geotechnical report where one exists) and the history of the defects. This step steers the on-site investigation and sets the equipment list.
On site: systematic survey and instrumentation
The site assessment includes:
- mapping of the cracks following the descriptive standards for facade disorders, which set out how to describe damage linked to ground movement;
- measurement of the opening with a crack gauge (0.1 mm accuracy), allowing classification per the CSTB guide: hairline crack (under 0.2 mm), crack (0.2 to 2 mm), structural fissure (over 2 mm);
- analysis of the pattern and orientation: stepped cracks (masonry joints), vertical cracks (localised settlement), horizontal cracks (lateral pressure, missing ties), map cracking (plastic shrinkage of concrete);
- installation of tell-tales or crack gauges on active cracks, to measure movement over several weeks;
- inspection of the foundations where accessible (inspection chamber, cellar, crawl space): founding depth, condition of the concrete, reinforcement, soil-foundation interface.
After the visit: written report and technical opinion
The report contains:
- location plans and annotated photographs of the cracks;
- classification by opening, pattern and location;
- analysis of the probable causes (see next section);
- the applicable liability regime (statutory warranties, Civil Code articles);
- repair recommendations and, on request, an estimate of the works.
Common causes of structural cracks in the 06, the 83 and the 13
Clay shrink-swell (RGA)
The leading cause of cracks in the Alpes-Maritimes and the Var is the differential movement of clay soils subject to moisture change. Clay shrink-swell (in French, retrait-gonflement des argiles, RGA) causes uneven settlement under the foundations when the soil loses water (drought, nearby vegetation), then swelling when the rain returns.
The BRGM has mapped the RGA hazard: numerous communes in the 06, 83 and 13 are graded medium to high hazard. Since 1 October 2020, a G2 AVP soil study (for foundation design) has been mandatory before any construction in an exposed zone (Article L. 132-6 of the Construction and Housing Code, formerly Article L. 112-21, introduced by the ELAN Act).
Typical RGA cracks are stepped, on load-bearing walls, start at openings and corners, and run through the full thickness of the wall. They often come with render detachment, slab settlement and distorted joinery.
Foundation defects
Foundations that are too shallow or under-sized cause differential settlement. Recurring failures: shallow footings on heterogeneous ground, no anchoring into the load-bearing layer (Article 1792 of the Civil Code: the contractor is presumed liable where a soil defect affects solidity), footings poured without any soil study.
Cracks caused by foundation defects are often vertical, evolving, and affect load-bearing walls over their full height. They can come with a measurable lean, read with a spirit level or laser distancemeter.
Missing or failed expansion joints
Long or L-shaped structures need expansion joints to absorb thermal movement. Missing or blocked joints produce horizontal or map cracking at the points of maximum stress (sills, lintels, parapets). This defect is a breach of the standards of practice: it engages the completion warranty (Article 1792-6) or, for separable equipment, the biennial warranty (Article 1792-3). Where the solidity or the intended use of the building is affected, the ten-year warranty (Article 1792) applies.
Ageing and corrosion
Reinforced concrete exposed to sea spray (Antibes, Nice, Cannes, Hyères) undergoes accelerated carbonation. Oxidising steel swells and splits the concrete locally (spalling). The cracks then run parallel to the reinforcement, with rust staining.
This defect usually falls under hidden-defect liability (Article 1641 of the Civil Code) where it was not detectable at the time of purchase, or under the ten-year warranty where it affects solidity within ten years of handover.
Warranties and liability regimes
Statutory construction warranties
Under Article 1792 of the Civil Code, contractors (project manager, builder, engineering firm) carry ten-year liability: any defect affecting the solidity of the works or rendering them unfit for their purpose engages their liability for ten years from handover. This warranty is of public order and backed by compulsory ten-year (décennale) insurance (Article L. 241-1 of the Insurance Code).
The completion warranty (Article 1792-6) obliges the contractor to repair, for one year after handover, every defect notified by the client, whatever its severity. The biennial warranty (Article 1792-3) covers, for two years, separable equipment elements (joinery, finishes) that fail to work properly.
Hidden defects in property sales
A buyer may claim under the hidden-defect regime (Blog 1641 et seq.) where cracks that existed but were not apparent at the sale make the property unfit for its intended use, or reduce that use to such an extent that the buyer would not have bought, or would have paid less, had they known. The action must be brought within two years of discovering the defect (Article 1648). A professional seller (developer, property trader) cannot contract out of it; a private seller is only liable if they knew of the defect.
Abnormal neighbourhood disturbance and natural disasters
Where cracks result from works on a neighbouring plot (earthworks, adjoining construction), liability for abnormal neighbourhood disturbance can be engaged (Article 1240 of the Civil Code). The assessment establishes the causal link. Where a drought natural-disaster order has recognised clay shrink-swell (RGA), the home multi-risk policy covers direct material damage, subject to the statutory deductible (Blog L. 125-1 and L. 125-2 of the Insurance Code). The assessment documents the claim for the insurer.
Repair principles
Solutions vary with the cause and severity:
- underpinning of the foundations (micropiles, ground beams, expansive resin injection) for differential settlement or inadequate bearing. Heavy works, supervised by a structural engineer;
- peripheral drains and removal of deep-rooted vegetation (trees at more than 1.5 times their mature height) to stabilise the moisture of clay soils;
- crack stitching or stapling with metal or composite staples, followed by repair mortar;
- retrofitted expansion joints in long structures, cut mechanically;
- corrosion treatment: cut out degraded concrete, passivate the steel, rebuild with structural repair mortar.
Any structural repair should be preceded by monitoring of the crack’s progression (tell-tales, crack gauges) and validated by a structural engineer where solidity is at stake.
Why survey before starting works
An independent technical assessment allows you to:
- avoid useless or under-sized works (cosmetic filling on an active crack);
- quantify liabilities and trigger the right recourse (contractor warranties, insurance, seller);
- build admissible technical evidence for the courts (Grasse, Nice, Draguignan, Toulon judicial courts);
- negotiate with the insurer in a natural-disaster or building-damage file;
- inform buyers of the true condition of a property before the deed is signed.
Working area and courts
Cassini Expertise covers the whole of the Alpes-Maritimes (06): Antibes, Cannes, Grasse, Valbonne, Mougins, Vallauris, Nice, Cagnes-sur-Mer, Saint-Laurent-du-Var, Menton – and the Var (83): Toulon, Hyères, La Seyne-sur-Mer, Fréjus, Saint-Raphaël, Draguignan, Brignoles.
Our reports are produced for the competent judicial courts: Grasse (Antibes, Cannes, Grasse, Valbonne, Vallauris, Mougins, Mouans-Sartoux), Nice (Nice, Menton, Cagnes-sur-Mer, Saint-Laurent-du-Var, Villefranche-sur-Mer), Toulon (Toulon, Hyères, La Seyne-sur-Mer) and Draguignan (Fréjus, Saint-Raphaël, Draguignan). On appeal: the Aix-en-Provence Court of Appeal.
Contact and quote
For any structural crack assessment, contact Cassini Expertise on 04 22 46 06 04. Office at 22 rue Vauban, 06600 Antibes. We reply within 24 working hours and provide a tailored free quote after reviewing your file (photographs, plans, description of the defects); the written report follows within 2 to 5 working days of the visit, depending on the investigations required.
See also: Defects After Reservation Lift in Nice: What to Do When the Issue Persists? · PACA Seismic Building Codes 2026: Guide for Antibes and Nice
Survey carried out by Frédéric Faucouneau, independent building expert – Antibes, Alpes-Maritimes (06), Var (83), Bouches-du-Rhône (13). Find out more
📅 Last updated 06/11/2026 - Cassini Expertise, independent building expert – departments 06, 83 and 13.