Why security doors are different to repair
A standard commercial door is repaired by swapping the failed part with a like-for-like replacement. A security door has the same approach but with a higher bar: the replacement part must match not just dimensionally but to the original certified specification. Using a cheaper or unrated equivalent invalidates the security certification of the assembly, which has insurance and compliance consequences.
For most security doors in UK commercial use, this is manageable — the certified parts are available, contractors maintain the spec knowledge, and the documentation chain is straightforward. But the discipline matters: a contractor who cuts corners on security door parts is creating exposure their customer may not understand until something goes wrong.
Common UK security door ratings
Four certification schemes dominate UK commercial security door use:
- LPS 1175 (Loss Prevention Standard 1175) — issued by LPCB, rates security ratings from 1 (lowest) to 8 (highest) based on attack-resistance time against defined tool sets. SR1-SR4 cover most UK commercial; SR5+ is rare outside critical infrastructure.
- Secured by Design — Police Crime Prevention Initiative, certifies doors and other security products to a published standard. Common on social housing and public-sector commercial buildings.
- PAS 24 (Publicly Available Specification 24) — security performance standard for enhanced security doorsets. Often referenced in domestic but used commercially too.
- STS 202 (Sold Secure) — independent attack testing standard rating security as Bronze, Silver, Gold, Diamond.
What can be repaired without losing certification
Most security door faults are repairable provided the right parts are used:
Lock cylinder replacement — straightforward, must match the original spec (e.g. TS 007 3-star, Sold Secure Diamond). Cylinders fail or need swapping after lost keys or staff turnover.
Multi-point lock gearbox replacement — common after years of use, replacement gearbox must match the original lock body and certification rating.
Hinge replacement — certified hinges only on rated doors. Standard commercial hinges will invalidate ratings on LPS 1175 SR3+.
Closer adjustment or replacement — the closer is part of the certified assembly but is generally interchangeable within the manufacturer’s range.
Strike plate or rebate repair — certified strikes only.
Anti-thrust plate addition — usually adds to certification rather than affecting it.
What invalidates certification
Specific items that void security ratings:
- Drilling extra holes through the door blade — even for hardware additions, the drill-out may compromise the door’s internal structural elements.
- Replacing certified hardware with cheaper non-rated equivalents.
- Modifying the frame structure (cutting new lock positions, etc.).
- Allowing structural damage from forced entry to remain unrepaired.
- Fitting non-rated glazing into a glazed security doorset.
- Replacing certified hinges with standard butt hinges.
Documenting security door repair
Security door work should produce documentation more rigorous than standard commercial repair:
Before-and-after photographs — condition on arrival, work in progress, finished state.
Parts list with certification references — make, model, certification scheme (LPS, Secured by Design, etc.), batch or serial numbers where applicable.
Written engineer report — what was damaged, what was replaced, what was retained, what was tested.
Confirmation that the doorset is back to original rated specification — explicit statement, signed.
This documentation is the insurance evidence for the repair and the regulator-facing evidence that the security rating has been preserved.
Industrial security door specifics
On industrial sites, security doors are typically heavier-spec (LPS 1175 SR2-SR4 common on plant rooms, server rooms, secure stores) and integrated with the site’s access control and intruder alarm system.
Common faults: multi-point gearbox failure (most common — high-cycle wear), cylinder wear, hinge sag under door weight (rare on properly-installed doors but happens), seal failure, access control integration issues at the lock-controller interface.
Industrial security door repairs are usually planned (scheduled service) rather than emergency, because the doors are robust enough to operate well past minor faults. The exception is when an attack has occurred, in which case same-day response is justified.
When upgrade is the right call
If the security spec of an existing door is lower than the current risk warrants — e.g. the building has changed use, stock value has increased, risk profile has shifted — an upgrade may be more cost-effective than incremental repair.
Common upgrade paths: standard commercial → LPS 1175 SR1 or SR2 doorset; SR1 → SR3 for higher-value stock; addition of access control and alarm integration. Each step is a planned project with a security audit, specification, install, certification.