Decennial guarantee for roofers: what it really covers

What is the decennial guarantee?

The decennial guarantee (garantie décennale) is a mandatory liability insurance for all construction professionals (roofers, carpenters, waterproofers...) covering them for 10 years from the acceptance of works for all damage compromising the structural integrity of the building or rendering it unfit for use, under Articles 1792 et seq. of the French Civil Code.

The decennial guarantee is one of the most important protections in French construction law. Yet many property owners don't know exactly what it covers — or how to verify that their contractor actually has it. This guide clarifies everything you need to know before engaging a roofer in Paris or Île-de-France.

The legal basis: Articles 1792 of the French Civil Code

The decennial guarantee is grounded in Articles 1792, 1792-1, 1792-2 and 1792-3 of the French Civil Code, which impose a presumption of liability on all constructors for damage to the building over 10 years.

Presumption of liability: Unlike ordinary civil law, the property owner does not need to prove the contractor's fault. It is sufficient to demonstrate the existence of a decennial defect. The burden falls on the contractor to prove they are not responsible.

What the decennial guarantee covers

For damage to be covered, it must meet one of two conditions:

Condition 1: Damage compromising structural integrity

In roofing and timber frame:

• Partial or total roof collapse
• Significant frame deformation
• Failure of structural frame elements
• Sliding or subsidence of the roof covering

In waterproofing:

• Persistent water infiltration compromising the structure (timber frame rot, damage to structural elements)
• Rainwater drainage system failure causing structural damage

Condition 2: Damage rendering the building unfit for use

Examples:

• Water infiltration making rooms uninhabitable (permanent moisture, toxic mould)
• Thermal insulation failure making the dwelling thermally unacceptable
• Flat roof waterproofing failure making the space unusable
• Acoustic defects related to poor roof installation

Intermediate defects (Article 1792-2)

Article 1792-2 extends the decennial guarantee to equipment elements inseparable from the building — elements that cannot be removed without damaging the main structure:

• Roof windows (Velux) integrated into the covering
• Lead flashings and soakers soldered to zinc
• Integrated valleys and gutters

What the decennial guarantee does NOT cover

1. Normal maintenance and upkeep: Progressive degradation due to lack of maintenance is excluded. Blocked gutters causing overflow damage because they were never cleaned are not covered.

2. Damage caused by the property owner: Modifications after reception, incompatible equipment installation, or failure to follow the contractor's maintenance recommendations.

3. Normal material ageing: Natural weathering of a roof — gradually wearing tiles, zinc thinning over decades — is not a decennial defect if materials were correctly installed.

4. Aesthetic damage only: Discolouration or slight appearance differences alone do not constitute a decennial defect.

5. Works not formally accepted: The guarantee runs from the date of formal acceptance (réception). Works without a signed acceptance record may create difficulties in case of dispute.

The three legal construction guarantees

Guarantee	Duration	What it covers
Parfait achèvement	1 year	All defects noted at acceptance
Biennale	2 years	Separable equipment elements
Décennale	10 years	Structural and habitability defects

Always draw up a detailed acceptance record (procès-verbal de réception) with your contractor when works are complete. This is the start date for all your guarantees.

How to verify your roofer's decennial insurance

Always ask for the certificate

Before signing any quote, request the contractor's decennial liability insurance certificate (attestation de responsabilité civile décennale). It must show:

• Company name and SIRET number
• Name of the insurer
• Policy number
• Period of validity
• Activities covered (roofing, zinc work, waterproofing, etc.)

Check activities carefully: A roofer whose insurance covers only "tile roofing" but not "zinc work" is not covered for your zinc works. The covered activities must match the specific works you are commissioning.

Red flags

• Refusal or delay in providing the certificate
• Certificate with expired validity date
• Activities covered don't match the works

A contractor without decennial insurance is taking a criminal risk and exposes clients to uncompensated damage. Since the 1978 Spinetta Law, this insurance has been mandatory.

The owner's additional protection: dommages-ouvrage insurance

As a complement to the contractor's decennial guarantee, property owners can take out dommages-ouvrage (DO) insurance before works begin. This allows:

• Rapid reimbursement of repair costs for decennial defects without waiting for a court decision
• Financing of emergency protective works

DO insurance is mandatory for new construction and optional for renovation, but strongly recommended for significant roofing works (full re-roofing, frame replacement), as it dramatically speeds up claims processing.

FDM ENERGIE: up-to-date decennial insurance, guaranteed works

FDM ENERGIE is a Qualibat RGE-certified roofing company holding valid decennial liability insurance covering all our activities: slate, tile and zinc roofing, flat roof waterproofing, insulation and timber frame work across Île-de-France.

We systematically provide our decennial insurance certificate with every quote and acceptance record. Your protection is our priority.

FDM ENERGIE: contact us for a free and transparent quote, with decennial insurance certificate and RGE certification provided as standard.