Automatic sprinklers: types, obligations and maintenance in Catalonia

Automatic sprinklers are the most effective active extinguishing system for controlling a fire in its initial phase. Unlike what films show, they do not all activate at once when an alarm goes off: each sprinkler responds independently to the heat it detects directly above itself. In real fires, more than 90% are controlled with a single sprinkler activated before firefighters arrive.

Their effectiveness is so high that insurance companies in some countries significantly reduce premiums when a building has sprinklers. In Catalonia, regulations require them in certain types of buildings and activities, but they are also a good investment in many cases where they are not mandatory.

In this guide we explain everything about sprinklers: how they work, what types exist, when regulations require them and how they must be maintained. You can complete this information with our guide on BIEs: installation, types and regulation, another key element of active fire protection.

How an automatic sprinkler works

An individual sprinkler is a simple device: a water outlet nozzle blocked by a heat-sensitive element. The sensitive element can be:

Glass bulb (the most common): a small glass cylinder filled with a coloured liquid that expands when heated until it breaks the bulb and releases the water. The liquid colour indicates the activation temperature:

• Orange: 57 °C (general use in inhabited areas)
• Red: 68 °C (standard in industrial and commercial areas)
• Yellow: 79 °C
• Green: 93 °C
• Blue: 141 °C (boiler rooms, ovens)

Metal fuse: a low melting point alloy that melts at the activation temperature. Less common in new installations.

When the bulb breaks, the pressurised water in the circuit pushes the sprinkler deflector, which generates a hemispherical spray that cools the fire and surrounding surfaces, preventing propagation.

The minimum pressure at the sprinkler head must be 0.5 bar for light-risk systems and 0.7 bar or more for ordinary and industrial risk, according to UNE-EN 12845.

Types of sprinkler systems

Wet pipe system

The most common and simplest. The pipe network is permanently full of pressurised water. As soon as a sprinkler activates, water flows out immediately.

Advantages: instant response, no complex components, easy maintenance.

Where to use: areas where there is no risk of freezing. Suitable for most buildings in Catalonia: communities of owners, hotels, offices, shopping centres, warehouses.

Dry pipe system

The pipe network is filled with compressed air (or nitrogen). When a sprinkler activates, the air escapes, pressure drops and a check valve allows water through. There is a slight delay between sprinkler activation and water arrival.

Where to use: cold rooms, covered outdoor areas with risk of freezing, outdoor parkings with sub-zero temperatures.

Limitation: delay in water arrival (5–60 seconds) can allow the fire to advance. Not recommended for high-risk areas.

Pre-action system

Combines dry pipes (filled with air) with a valve that opens only when it receives a signal from the fire detection panel. Both a detector must activate the alarm and heat must break the sprinkler bulb for water to flow.

Advantages: double protection against accidental activation (a blow that breaks a sprinkler without fire does not flood the area). Ideal for server rooms, museums, archives, libraries or any space where water causes severe damage.

Limitation: more complex, more expensive, requires more maintenance.

Deluge system

All sprinklers have the nozzle permanently open (no bulb). Water does not flow normally because the network is dry. When the detection panel sends the signal, a valve opens the water supply and all sprinklers activate simultaneously.

Where to use: aircraft hangars, petrochemical plants, high-power transformer areas, theatre stages. Any place where it is necessary to instantly cover the entire surface with water in the maximum possible quantity.

UNE-EN 12845 standard: risk classification

UNE-EN 12845 classifies the risk of spaces into three categories that determine system design:

| Category | Description | Examples | |---|---|---| | Light Hazard (LH) | Low fire load, non-flammable | Hotel rooms, offices, meeting rooms | | Ordinary Hazard 1 (OH1) | Moderate fire load, not easily flammable materials | Light workshops, paper warehouses, commercial areas | | Ordinary Hazard 2–4 (OH2–OH4) | Higher fire load or more flammable materials | Wood warehouses, paper storage, textile industry | | High Hazard 1–3 (HH1–HH3) | High fire load, highly flammable materials | Flammable liquid warehouses, plastic factories |

The category determines: water discharge density (L/min/m²), system operating area, design pressure and pipe diameter.

When they are mandatory in Spain: CTE DB-SI

The CTE DB-SI establishes the obligation for sprinklers in the following cases:

| Building use | Condition | |---|---| | Public residential (hotels, tourist apartments) | Total area > 5,000 m² | | Commercial | Total area > 3,500 m² | | Public attendance | Total area > 3,500 m² | | Hospital | Hospitalisation areas, intensive care and operating theatres | | Covered parking | Area > 10,000 m² or more than 3 basement levels | | Any use | Evacuation height > 80 m |

For industrial establishments, the RSCIEI (RD 2267/2004) establishes when sprinklers are mandatory based on the configuration type (A, B or C) and the intrinsic risk level (low, medium, high). In general terms:

• Configuration A (inside another building): mandatory sprinklers if risk is medium-high and area exceeds 500–1,000 m².
• Configuration B (exclusive building): mandatory sprinklers for high risk if area exceeds 2,500 m².
• Configuration C (isolated): mandatory sprinklers for very high risk or very large areas.

Mandatory maintenance under RIPCI

The RIPCI (RD 513/2017) establishes the following maintenance programme for sprinkler systems:

| Operation | Frequency | Responsible | |---|---|---| | Check of pressure gauges, valves and signage | Monthly | Installation owner | | Alarm valve test (hydraulic activation) | Quarterly | Authorised maintenance company | | Check of deluge valve alarm flow (if applicable) | Semi-annually | Authorised maintenance company | | Complete inspection of sprinklers, pipes and supports | Annually | Authorised maintenance company | | Hydrostatic pipe test | Every 5 years | Authorised maintenance company | | Replacement of sample sprinklers (UNE-EN 12259 test) | Every 10 years | Authorised maintenance company |

Sprinklers must never be painted, coated with lime or corroded. If an inspection finds a sprinkler with any kind of coating or bulb damage, it must be replaced immediately.

Common errors in sprinkler installations

• Storage exceeding design height: if goods are stored above the system design level, sprinklers may not reach the fire with sufficient density.
• Obstacles beneath sprinklers: shelving, beams, equipment or any element interrupting the spray pattern drastically reduces effectiveness.
• Closed isolation valves: if a section valve is closed for repair and not fully reopened, the system loses pressure. Monthly checks of valve status prevent this error.
• Painted or covered sprinklers: during works or renovations, sprinklers are covered with plastic bags to protect them from paint or dust. If they are not removed, the sprinkler cannot activate.
• Incorrect bulb temperature for the space: installing sprinklers activating at 57 °C in a boiler room or on a metal roof causes accidental activations with ambient heat.

"The most frequent error in industrial buildings with sprinklers is storing goods above the system design height. If the system was designed to protect up to 4 metres and storage reaches 6, sprinklers cannot reach the fire with sufficient density to control it. The system is installed, passes all inspections, but will not work when you need it."

— Technical manager, Igniescut

Frequently asked questions

When are automatic sprinklers mandatory in Spain?

The CTE DB-SI requires them in hotels and residences larger than 5,000 m², shopping centres over 3,500 m², hospitals and large-capacity garages. The RSCIEI requires them in industrial establishments of high intrinsic risk. Outside these obligations, installation is voluntary, although 90% of fires controlled by sprinklers are extinguished with a single sprinkler activated.

How often should sprinklers be inspected under RIPCI?

Quarterly valve and pressure checks, semi-annual alarm test, and annual complete inspection with RIPCI certificate issued by an authorised company. The building owner must carry out monthly visual checks to detect damage or obstructions.

What is the difference between a wet and a dry system?

In a wet system, the pipe is always full of pressurised water and water flows immediately. In a dry system, the pipe contains air or nitrogen and water can take up to 60 seconds to arrive. The dry system is used where pipes could freeze or where permanent water in the installation is not acceptable.

How much does it cost to install automatic sprinklers?

A wet system for ordinary risk can cost between 15 and 30 €/m² installed, including project and commissioning. In industrial buildings with pre-action or deluge systems and high risk, the cost can exceed 50 €/m².

Sprinkler installation and maintenance in Catalonia

At Igniescut we design and install automatic sprinkler systems in hotels, shopping centres, industrial buildings and parkings in Barcelona, Tarragona and throughout Catalonia according to UNE-EN 12845. We also carry out maintenance contracts with all RIPCI certificates required.

Contact us for a no-obligation study of your installation or the needs of your building or industrial premises.