Steel louvred doors

Steel louvred doors are security doorsets that ventilate while they protect. The leaf carries fixed louvre blades for airflow, and the whole assembly is tested to LPS 1175. ArxBridge supplies and installs them for plant rooms, substations and service areas across the UK. They belong to the security range for ventilated openings.

• SR2 to SR4Rated louvred doorsets
• Louvred leafVentilation that keeps its rating
• Steel bladesFixed, attack-resistant louvres
• Third-party test evidenceSupplied with every doorset

What steel louvred doors are

A louvred security door replaces part or all of the solid leaf with angled steel blades. Air passes between the blades; tools and hands do not. The blade profile, the blade fixings and the surrounding leaf are all inside the LPS 1175 test, so the ventilation opening does not become an attack opening.

These doors answer a common conflict: plant and electrical rooms need constant airflow, but they also hold valuable equipment and need a rated door. A solid security door would starve the room of air; an ordinary louvred door would give an attacker a ready-made opening. The rated louvred doorset resolves both. The LPS 1175 guide explains the ratings.

Free area is an engineering number. The airflow through the louvres must match what the room needs. State the required free area at quote stage so the blade layout is designed around it.

Choosing the right rating for steel louvred doors

Higher ratings mean deeper blades and tighter profiles, which reduce the free area per door. On large plant rooms this is solved with double leaf doorsets or with a louvred door plus a separate rated louvre panel in the wall. The ventilation calculation comes before the door schedule, not after.

How louvred doorsets are built

The leaf is a steel frame holding banks of pressed steel louvre blades. Each blade is angled to shed water and to deny a straight line for tools, and each blade fixing sits inside the tested assembly. Behind the blades, a security mesh or perforated steel screen adds a second barrier without choking the airflow.

The outer leaf sections, the meeting stiles on double leaf versions, the frame and the locking all match the doorset rating. Locking is multi-point on SR3 and above. Because the leaf is part open, the frame anchorage and the blade retention get particular attention in the test: the attack goes for the louvres first.

Pairing steel louvred doors with other ratings

Fire ratings combine with louvred doors where ventilation must pass through a fire compartment line: E 60 and E 90 louvred doorsets are tested to EN 1634-1 (see fire rated louvre doors). Ballistic louvres exist for sites facing firearms as well as forced entry (see ballistic louvre doors), and blast rated louvred doors for pressure-rated ventilation (see blast resistant louvred doors).

Each combination is its own tested assembly. A security louvre and a fire louvre are different products; where both ratings are needed, the doorset is tested for the pair. State every requirement at quote stage.

Where louvred security doors are used

Data centres ventilate UPS rooms, battery rooms and generator enclosures through rated louvred doorsets (see data centres). Utilities and energy sites use them on substations, switch rooms and pump houses (see utilities and energy). Commercial buildings use them on boiler rooms, bin stores and service yards. Anywhere that needs air and a rating is a candidate.

Cost and lead time factors for steel louvred doors

The rating sets the blade depth and the steel content, so SR4 louvred doorsets cost and weigh more than SR2. Free area is the next driver: more airflow means more blade banks, larger leaves or double leaf configurations. The security screen behind the blades adds material and assembly time.

Finish matters in plant environments: powder coating to a marine-grade system suits coastal or chemical sites. Hardware follows the rating, and access control on a plant room door is common. Site installation is usually straightforward, but large double leaf doorsets need clear access for the frame. No prices are published; quotes follow the schedule and the free area calculation.

How to specify louvred security doors

1. State the free area. Give the airflow the room needs, so the blade layout is designed around it.
2. Name the rating. SR2 (B3), SR3 (C5) or SR4 (D10) to LPS 1175, per door.
3. Fix the configuration. Single or double leaf, full or partial louvre banks.
4. Set hardware and finish. Locks, access control, and the coating system for the environment.
5. Send the schedule. Openings, quantities and site location complete the quote.