BS EN 15254-7:2012 pdf download – Extended application of results from fire resistance tests — Non- loadbearing ceilings Part 7: Metal sandwich panel construction
For changes in emissivity >10 %, surface temperatures can be estimated from small-scale tests in accordancewith 6.1 where the surface temperatures of the new panel are compared to the one tested in the referencescenario. lf appropriate calculation methods are available, the surface temperatures can also be calculatedand compared, provided that temperature-dependent thermal resistance values for the core material areavailable.
The energy content of the coating on the exposed side is small and will not affect the fire resistance propertiesof the sandwich panel.Test results are valid for all coatings.
lf modifications in the coatings on the non-exposed side are made, compared to the tested one, the ignitabilityof the modified coating shall be higher or equal to that tested. This can be checked by conducting small-scaletests according to 6.1.Test results are valid for all colours of the same type of coating. Variations in the metal material
The following rules are valid for extended applications.
1)The test results are valid for all grades of tested normal steel, and if once tested as stainless steel for all grades of stainless steel.(A change from mild steel to stainless steel is not possible without conductingfurther tests.)
2For other types of metals, the test result is valid for tested type only.
3)For panels with perforated facings on one or both sides of the panels, a test result achieved with a perforated facing is always valid for non-perforated facings in the same position as in the tested product.Test results for a product tested with non-perforated facings are valid only for a product with perforatedfacings on the fire exposed side where the perforation area is not greater than 25 % and where thereaction to fire class of the core material is A2-s1, d0 or better. Other changes are not allowed. in profile geometry of facing
The following rules are valid for extended applications.
1)For flat or small profiling (between 0 mm and 5 mm): test results are valid for any change.
2)For profiles greater than 5 mm: test results are valid for variations + 50 %of profile depth.
5.2.3 Variations in the adhesive
This paragraph is valid only for panels with adhesively bonded cores. The following rules apply for anadhesive with no strength at high temperatures (> 500 C) which means that the metal sheet on the exposedside will disconnect from the core in the very beginning of a fire and the construction will loose its sandwichcapability. For this reason, an organic adhesive cannot be changed to a non-organic one or vice versa.
Normally the energy content of the adhesive is small and will not affect the fire resistance properties of thesandwich panel.The following rules are valid for extended applications.
1) For gross calorific potential PCS value 0 MJ/m’ to 4 MJ/m : the results are valid for all adhesives when gross calorific potential PCS value stays between 0 MJ/m2and 4 MJ/m2.
2) For gross calorific potential PCS value > 4 MJ/m2:.the results are valid for gross calorific potential PCS values lower than the tested adhesive within manufacturing tolerances.
3) For gross calorific potential PCS value > 4 MJ/m2 and > 1 ,1 5*PCS: test results shall be reduced by the same % as the gross calorific potential PCS value is over the initial tested adhesive.
5.2.4 Variations in the core material General The following main core materials are used in sandwich panels: mineral wool (MW), polyurethane (PUR), extruded polystyrene (XPS), expanded polystyrene (EPS), phenolic foam and cellular glass. The behaviour of these core materials regarding fire is different and cannot be compared. Changes from one core material to another are therefore not allowed in any extended application. Variations within each core material group are allowed in accordance with the rules given in to There are several factors in the different core materials that affect the fire properties of the core and of the sandwich panel. It is therefore not possible to extend the results from one core material producer to be valid for apparently similar materials from another producer. Mineral wool (MW)
Mineral wool consists of stone wool and glass wool. Generally, the greater the density of the mineral wool the higher the flexural strength of the panel. Density will be dictated by room-temperature structural design requirements. However, variation in density affects the I-insulation value. The results are always valid for an increase in density in the density range 50 kg/m 3 to 1 50 kg/m 3 . A decrease in density is allowed down to -1 0 % of tested density.