Single burning item test for timber with fire protection

Fire safety in construction

Fire protection of timber structures and finishing structural materials is actual due to the high combustibility of these materials. The technical characteristics for protected timber structures in case of fire, determined by the single burning item test (SBI), are considered in the paper. Nine thin-layered lacquers and paints fire protections, which were differed by the type of fire resistance and chemical contents, were analyzed. The timber specimens treated by such fire protections as the paints, impregnations, lacquers and water glass were tested by SBI method. It was shown, that the lacquer on the base of the acryl resin has a significant influence on the fire growth rate indices FIGRA and smoke growth rate SMOGRA on the initial stage of combustion (FIGRA – 2948.78 W/s, SMOGRA – 101.28 m2/s2). Traditional fire protection by the water glass shows the high fire growth rate indices FIGRA (268.63 W/s) and total smoke production TSP600s (163.13 m2). The low levels of the both values did not confirm a classic consideration of the water glass as effective fire protection of timber members. Type of timber base and assembling method (with or without air gap) has a significant influence on the effectiveness of fire protection. Analogous results obtained for the intumescent paint and two types of lacquers. The modern water impregnations that contains phosphoric acids characterized by the low expenditure (mean value 250 g/m2) and low values of smoke growth rate and total smoke production in 3MJ and 33 m2, correspondingly. These impregnations provides a class Bs1d0 of fire protection by the European classification.