Fire protection boards
What are fire protection boards?
Fire protection planners use fire protection boards to achieve the goals of structural fire protection. The first priority is to prevent fires. If there is a fire, the fire must be controlled! In order to achieve this, fire protection boards withstand a specified fire duration. These are, for example, 30, 60 or 90 minutes. During this time, the boards ensure that the fire stays within a so-called fire compartment. They prevent the fire from spreading to other parts of the building.
Fire protection boards (also called drywall boards) are available in different dimensions in Germany:
- Variant 1: length 2000 mm, width 600 mm, thickness 12.5 mm, weight approx. 12 kg.
- variant 2: length 2000 mm, width 1250 mm, thickness 12.5 mm, weight approx. 24 kg.
Because every build is different, manufacturers supply additional dimensions. The narrow plates are well suited when they have to be assembled alone. The longer the boards have to withstand the fire, the thicker they have to be. To achieve this, the drywaller bolts two or more boards together.
What is protected with fire protection boards?
For a building to withstand a fire, it is important to protect the columns and beams. Steel conducts heat well, which is disadvantageous in a fire. This causes steel structures to heat up, weaken and fail quickly. Therefore, construction workers attach the plates to steel members. With multi-layer boards, steel components can also withstand a fire for a longer period of time. The technical term for this duration is the so-called fire resistance duration.
Fire protection boards primarily protect steel components. Other building materials such as concrete and wood benefit in the event of a fire because they conduct heat much less well. It is therefore rather unusual to protect columns and beams made of concrete with fire protection boards.
Larger buildings are often heavily automated. Because window ventilation is too time-consuming, there is usually ventilation. In addition, there are often installation shafts to accommodate the building's technology. Both the ventilation ducts and the installation shafts are mostly made of sheet steel. Since the ducts run through several fire compartments, they could conduct heat in the event of a fire. In order to prevent this, the manufacturers offer fire protection boards for shafts. The length and width of these plates are optimized for the shafts.
Instead of accommodating the installation in shafts, it can run between the raw ceiling and a visible ceiling. The visible ceiling often consists of fire protection boards to ensure fire protection. Suspensions carry the loads on to the soffit. Alternatively, the visible ceiling can be attached to the walls. Usual technical terms for the second variant are long-span ceilings, wide-span beam ceilings or self-supporting ceiling .
What fire resistance duration can fire protection boards achieve?
The fire resistance period relates to a standardized fire progression, the so-called ISO standard fire. There are also other fire curves (see section "Fires"). What fire resistance do fire protection boards achieve? In addition to fire temperature, this depends on the selected product. The list gives an impression of the approximate thickness of the fire protection boards required. The exact thickness can be found in the manufacturer's product catalogues. For example, the fire resistance class F30 in the list below means that the component withstands the fire for 30 minutes in the fire test. The fire resistance class F60 stands for 60 minutes. The "F" is the old national designation in Germany, while the new European designation uses an "R".
- Fire resistance class R30 or F30 (fire retardant): single layer (t=12.5 mm);
- fire resistance class R60 or F60 (highly fire-retardant): single-layer (t=12.5 mm) or two-layer (t=25 mm);
- fire resistance class R90 or F90 (fire-resistant): two-layer (t=25 mm);
- fire resistance class R120 or F180 (highly fire-resistant): two-layer (t=25 mm) or three-layer (t=37.5 mm).
- fire resistance class R180 or F180 (highest fire resistance): three layers (t=37.5 mm).
What are fire protection boards made of?
So far, plasterboard has dominated the market for fire protection boards. In the event of a fire, the crystal water bound in the plaster evaporates. This cools the plate. The manufacturers either provide the plaster with cardboard on both sides, which absorbs the tensile forces in the event of bending stress. Or they do without cardboard and instead arrange glass fibers in the plaster to absorb the tensile forces. In addition to plasterboard, various manufacturers offer other fire protection boards:
- Fire protection boards out of chipboard;
- fire protection boards out of rockwool;
- fire protection boards out of mineral wool;
- fire protection boards out of vermiculite;
- fire protection boards out of clay.
How are fire protection boards processed and fastened?
How the drywaller cuts and mounts the boards depends heavily on the material chosen. Plasterboard boards are popular because they are easy to work with. The drywaller cuts through the cardboard layer with a cutter knife and cuts the board. Then he can break it off over an edge. You can find more hints here. Once you have decided on a product, it is best to use the manufacturer's data sheets and technical information to find out more. Most manufacturers offer the documents free of charge on their websites. You may also be interested in the following two videos on this topic: