CERTASS Insurance & Risk Guide for Window, Door & Glazing Installers
CERTASS-registered installers are responsible for the correct installation of windows, doors, glazed units and building fabric components. These tasks come with significant risks, especially around water ingress, glass handling and structural alteration.
This CERTASS Insurance & Risk Guide, created by SRS Insurance, explains:
- The key risks CERTASS installers face
- Essential insurance protections
- Common glazing & installation claims
- Dangerous exclusions to watch out for
- How to protect your business properly
This guide is insurance and risk guidance only, not compliance or audit advice.

Key Risks for CERTASS Installers
Glazing and building fabric installation is high-risk due to fragile materials, customer properties, exposure to weatherproofing risks and structural work.
1. Water Ingress & Damp Damage
One of the most common and expensive claim types.
Caused by:
- Poor sealing
- Incorrect frame installation
- Failure to level windows
- Missing trims or sealant
- Defective door thresholds
Results include:
- Rot
- Damp patches
- Internal decoration damage
- Customer disputes
Claims often range £5,000–£25,000+.
2. Glass Breakage & Handling Damage
Glass is expensive, heavy and fragile.
Risks include:
- Dropping panes
- Impact damage
- Wrong measurements
- Tight installations causing breakage
Large units — especially aluminium or triple-glazed — can cost £2,000–£12,000+ to replace.
3. Working at Height Risks
CERTASS installers often work on:
- Ladders
- Scaffolding
- Dormers
- Conservatories
- 1st/2nd floor windows
Risks include:
- Falls
- Dropped tools
- Dropped glazing units causing property damage
4. Structural Damage to Building Fabric
Window and door installers frequently remove or alter:
- Lintels
- Masonry
- Timber frames
- Fascia panels
- Brickwork
- Render
Damage here is a frequent source of PL claims.
5. Incorrect Surveying & Measuring
Survey errors cause:
- Misfit units
- Redelivery costs
- Customer delays
- Additional labour
- Disputes & claims
Professional Indemnity (PI) is important for surveying firms or installers who measure.
6. Security & Locking System Failures
If a door or window is installed incorrectly:
- Customers can be locked out
- Break-ins may occur
- Insurance claims may be directed at the installer
Essential Insurance Covers for CERTASS Installers
1. Public Liability Insurance (PL)
PL covers injury or property damage caused during your work.
For CERTASS installers, PL should include:
- Glazing installation
- Window & door fitting
- Aluminium, UPVC & timber frames
- Water ingress cover
- Working at height
- Building fabric work
- Structural damage cover
Recommended limits:
- Domestic installers: £2m–£5m
- Commercial installers: £5m–£10m
2. Professional Indemnity Insurance (PI)
PI is important for installers who:
- Carry out surveys
- Measure for window/door sets
- Specify products
- Provide design advice
- Handle commercial contracts
- Deliver U-value or compliance guidance (advice only)
PI protects against:
- Wrong measurements
- Incorrect product specification
- Documentation/advice errors
Recommended limits: £250k – £1m
3. Employers’ Liability Insurance (EL)
Legal requirement if you employ:
- Installers
- Fitters
- Trainees
- Labour-only subcontractors
Legal minimum: £10m.
4. Tools & Equipment Insurance
Glazing tools are high-value and essential for safe working:
- Glass suckers (often £300–£600 each)
- Power tools
- Cutting tools
- UPVC trim equipment
- Commercial glazing gear
Tool theft is extremely common.
5. Contract Works Insurance
Useful for:
- Conservatory installations
- Large glazing projects
- Curtain walling
- New build contracts
- Renovation works
Protects materials and work in progress.
Common Insurance Mistakes CERTASS Installers Should Avoid
No cover for water ingress
Many generic policies exclude weatherproofing claims — this is a major risk.
Wrong trade description
Your policy MUST list glazing or window installation.
Avoid generic terms like:
- “Handyman”
- “General builder”
- “Property maintenance”
No working-at-height cover
Most jobs involve ladders or scaffolding.
PL only, no PI
Surveying & measuring errors are professional liabilities.
Policies excluding fragile items
Some insurers exclude damage to:
- Glass
- Mirror
- Decorative panels
Not suitable for CERTASS installers.
‘Property worked upon’ exclusions
This exclusion means no cover for damage to:
- Window frames
- Doors
- Reveals
- Brickwork
- Glazing units
CERTASS installers must avoid this.
Using subcontractors incorrectly
Labour-only subcontractors must be covered under EL.

Typical Claims Faced by CERTASS Installers
Water Ingress Claim (£5,000–£25,000+)
Faulty sealing or incorrect installation.
Dropped Glass Unit (£800–£6,000+)
Breakage during lifting or positioning.
Damage to Brickwork or Masonry (£2,000–£12,000)
During removal of old frames.
Fall From Height (£8,000–£40,000+)
Installer injury or dropped equipment hitting property.
Security Claim (£3,000–£12,000)
Faulty installation leading to break-in.
Tool Theft (£1,000–£6,000)
Common, especially vans targeted at night.
Recommended Insurance Checklist for CERTASS Installers
CERTASS glazing installers should ensure their insurance includes:
- Glazing installation
- Window & door fitting
- Water ingress cover
- Building fabric cover
- Working at height cover
- Professional indemnity (for surveying/measuring)
- Tools & equipment cover
- Employers’ Liability
- Public Liability £2m–£10m
- “Property worked upon” cover
This is risk protection, not compliance advice.
Why CERTASS Installers Choose SRS Insurance
- Specialists in glazing, window & door installer insurance
- Policies tailored for structural and weatherproofing risks
- A-rated UK insurers
- Fast documentation
- Tools cover available
- Suitable for both domestic and commercial glazing teams
We insure CERTASS installers across the UK.
