Security doors

Security doors are steel doorsets tested to LPS 1175 for forced entry, rated SR2 to SR5. ArxBridge supplies and installs the full range for commercial, public and industrial buildings across the UK. The right rating follows the attack time in your risk assessment. They are the core of the security range.

• SR2 to SR5LPS 1175 doorset range
• 3 to 10 minutesRated attack time, B3 to E10
• Single and double leafGlazed options available
• Third-party test evidenceSupplied with every doorset

What a security door is

A security door is a complete doorset: leaf, frame, locks, hinges and fixings tested together as one assembly. The rating does not belong to the leaf alone. It certifies that the whole assembly resisted the tools of its category for the rated minutes. ArxBridge supplies these doorsets with third-party test evidence for the exact configuration ordered.

Doorsets are built in steel, with single leaf, double leaf and glazed configurations. Glazed versions use attack-rated glass tested with the frame, so the vision panel does not become the weak point. Hardware is specified as part of the tested assembly: hinges, multi-point locks, closers and cylinders that match the rating. The LPS 1175 guide explains how the ratings are derived.

A rating is only as good as the assembly. The LPS 1175 test covers the leaf, frame, locks, hinges and fixings together. Swapping one part for an untested equivalent voids the rating.

Picking the rating for security doors

Pick the rating from the threat, not from habit. A storeroom door and a cash office door on the same site can carry different ratings. Where the risk assessment is uncertain, ask for security consultancy before the schedule is fixed.

How a rated doorset is built

The leaf is a steel shell with internal reinforcement positioned where the test tools attack: around the lock, the hinges and the meeting stiles. The frame is anchored into the surrounding wall, because a strong leaf in a weak frame fails at the frame. Fixings are part of the tested assembly, not an installer choice.

Locking is multi-point on higher ratings, spreading the load across the leaf edge. Hinges are rated for the leaf weight and protected against removal. Cylinders and escutcheons resist drilling and pulling to the level of the doorset rating. On glazed doorsets, the glass is LPS 1270 rated and retained by a tested bead system, so the whole aperture keeps one rating.

Pairing security doors with other ratings

One doorset can carry more than one rating. Fire and forced entry is the most common pair: the assembly is tested to EN 1634-1 for fire and to LPS 1175 for attack (see fire and security doors). Ballistic ratings can be added where the threat includes firearms (see bullet resistant doors), and blast ratings where vehicle bombs are a concern (see blast resistant doors).

Thermal performance can be combined too: thermally broken steel doorsets hold a security rating with a lower U-value (see thermally broken doors). State every rating at quote stage. Each combination needs its own test evidence for the pair, not two certificates stapled together.

Where security doors are used

Government and defence estates specify SR3 and SR4 for offices, armouries and communications rooms (see government and defence). Data centres use rated doorsets on plant rooms, UPS rooms and the routes between security zones (see data centres). Retailers protect stockrooms and cash offices, and schools and colleges secure plant rooms, IT suites and server cupboards. The right rating follows the room, not the building.

Cost and lead time factors for security doors

The rating is the first driver: higher ratings need heavier construction and longer test programmes. Leaf size and configuration come next; double leaf and oversized doorsets take more material and more factory time. Glazing adds a second tested component, the glass and its retention system. Hardware choice matters too: access control integration, panic hardware and high-security cylinders each add supply and commissioning time.

Finish is a further factor. Powder coating in a standard colour is quicker than a special finish or a marine-grade system. Quantity changes the unit economics: a schedule of identical doorsets runs faster per door than ten different one-offs. Finally, site conditions affect installation time: restricted access, out-of-hours working and phased handovers all extend the programme. No prices are published here; every quote is built from the schedule.

How to specify security doors

1. Set the rating. Name the SR level and the Issue 8 code, for example SR3 (C5), in the door schedule.
2. Survey the openings. Record structural opening sizes, wall construction and floor levels for each door.
3. Choose the configuration. Single or double leaf, glazed or solid, and the swing direction.
4. List the hardware. Locks, cylinders, closers, panic hardware and any access control, all to suit the rating.
5. Send the schedule. Drawings, quantities and the site location are enough for a firm quote.