The use of sustainable natural resources has been practiced by the construction sector as a means to reduce
energy demand and increase the efficiency of buildings. In this sense, wood and wood-based materials are alternative and
renewable material sources that can be effectively used in building elements, such as doors and partition walls, which are
required to provide adequate thermal, acoustic, and fire resistance performance. Such elements play an important role in
the fire compartmentation of buildings. Appropriate selection of materials with a reduced potential of ignition and
enhanced fire behaviour may reduce the heat flux, and the passage of hot gases and smoke, thus minimizing fire hazards.
In the case of wood products, the combustibility of wood usually limits its use in fire-resistant components. However, the
fire performance of wooden assemblies can be improved by using engineered wood products and insulation materials,
which can be assembled into multilayer systems. This work investigates the performance of wood and wood-based
multilayer panels exposed to ISO 834 standard fire curve to improve the knowledge about their fire resistance in terms of
insulation (I) and integrity (E) criteria. The study considers pinewood, OSB (oriented strand board), and moistureresistant
MDF (medium-density fibreboard) of different thicknesses. Rockwool with a thickness of 27 mm was also used
as a core material. The multilayer systems have a dimension of 580×580 mm, fixed to a wood frame and mounted to a
wall made of refractory bricks and mortar. The composite panels were tested in a small-scale furnace. During each test,
temperatures were measured using type k thermocouples attached between layers and to the panel’s surfaces and wood
frame. The specimens were considered to have failed when the insulation and integrity criteria were met according to EN
1363-1. The results showed that a 1-hour insulation fire resistance was achieved when using 16 mm-thick MDF panels on
both sides and rockwool as a core material. Similar assemblies using 6 mm-thick and 10 mm-thick MDF panels reached
30 min., and 40 min., respectively. The specimen with 20 mm-thick pinewood on both sides and rockwool core had an
insulation fire resistance of 41 min. but had one of the highest superficial masses and highest total thickness amongst
tested specimens. Pinewood has been tested as a core material sandwiched between two 10 mm- thick MDF panels, and
its insulation fire resistance was 30 min. The assembly with 15 mm-thick OSB placed between two 10 mm-thick MDF
boards had the smallest insulation fire resistance of around 27 min. The fall-off of the exposed panel and warping of the
edges of the panels greatly influenced the integrity behaviour of the samples. The insulation performance was mostly
affected by the type of material and its thickness, as well as by the relative position of the layer in the composite
assembly. The results provide important data regarding heat transmission effects and integrity issues related to the
exposure of wood and wood-based composite multilayer systems under fire.
This work was developed within the scope of the project NORTE-01-0247-FEDER-072225, supported by North
Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement,
through the European Regional Development Fund (ERDF).
