Lo más importante
- Sprinklers activate individually: only the sprinkler head detecting heat opens, not all at once; in most fires controlled by sprinklers a single sprinkler head is enough.
- The reference standard for the design, installation and maintenance of sprinkler systems in Spain is UNE-EN 12845, which classifies risks as light, ordinary (OH1–OH4) and industrial (HH1–HH3).
- CTE DB-SI requires sprinklers in every building with an evacuation height above 80 m, in public residential buildings above 28 m or 5,000 m², in sales areas > 1,500 m² with a fire load > 500 MJ/m² and in robotic car parks.
- The RSCIEI requires them in industrial establishments of High Risk (level C) and in Medium Risk configurations with surface area exceeding regulatory thresholds.
- Maintenance must be carried out by an authorised company every quarter (valve check), semi-annually (alarm test) and annually (complete inspection with RIPCI certificate).
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 most fires controlled by sprinklers a single sprinkler head is enough.
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.
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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) | Evacuation height > 28 m or built area > 5,000 m² |
| Commercial | Sales area > 1,500 m² with fire load > 500 MJ/m² |
| Public attendance | Not required by use |
| Hospital | Not required by use (BIE and detection always required) |
| Car park | Only in robotic car parks |
| Kitchens | Installed power > 20 kW (hospital or public residential) or > 50 kW |
| Any use | Evacuation height > 80 m |
For industrial establishments, the RSCIEI (RD 164/2025) makes the obligation depend on the configuration of the establishment (buildings AV, AH, B or C; open spaces, type D), the intrinsic risk level and the area of the sector; the exact thresholds are in its current table, which should be checked case by case.
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."
— Igniescut technician network
Frequently asked questions
When are automatic sprinklers mandatory in Spain?
The CTE DB-SI requires automatic extinguishing in every building with an evacuation height above 80 m, in public residential buildings above 28 m or 5,000 m², in sales areas above 1,500 m² with a fire load above 500 MJ/m², in robotic car parks and in kitchens above 20/50 kW. The RSCIEI requires them in industrial establishments of high intrinsic risk. Outside these obligations, installation is voluntary, although in most fires controlled by sprinklers a single sprinkler head is enough.
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 is the most affordable option, while pre-action or deluge systems in industrial buildings with high risk cost considerably more. The final price per square metre, including project and commissioning, is set by the network technician after assessing the installation.
Sprinkler installation and maintenance in Catalonia
Igniescut coordinates the design and installation of automatic sprinkler systems in hotels, shopping centres, industrial buildings and parkings in Barcelona, Tarragona and Madrid according to UNE-EN 12845, through the licensed technicians in its network. We also coordinate 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.