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Materials Database

BR 443 design thermal conductivity values for common UK construction materials.

MaterialCategoryλ (W/m·K)
Brickwork (outer leaf)Masonry0.770
Brickwork (inner leaf)Masonry0.560
Concrete block (medium density)Masonry0.510
Concrete block (high density)Masonry1.130
Concrete block (lightweight)Masonry0.190
Aircrete blockMasonry0.110
Dense concreteMasonry1.700
Lightweight concreteMasonry0.380
Stone (ite)Masonry1.800
Stone (sandstone)Masonry1.300
Mineral wool (glass)Insulation0.035
Mineral wool (stone)Insulation0.038
EPS (Expanded Polystyrene)Insulation0.038
XPS (Extruded Polystyrene)Insulation0.034
PIR/PUR BoardInsulation0.022
Phenolic FoamInsulation0.020
Cellulose (blown)Insulation0.040
Sheep woolInsulation0.039
Wood fibre boardInsulation0.038
CorkInsulation0.040
Softwood (pine, spruce)Timber0.130
Hardwood (oak)Timber0.180
PlywoodTimber0.130
OSBTimber0.130
ChipboardTimber0.140
MDFTimber0.140
Plasterboard (standard)Boards0.210
Plasterboard (thermal)Boards0.190
Cement boardBoards0.230
Calcium silicate boardBoards0.170
Gypsum plasterBoards0.400
Sand/cement renderBoards1.000
Breather membraneMembranes0.170
VCL (vapour control layer)Membranes0.170
Bitumen feltMembranes0.230
Air cavity (unventilated)AirR=0.18
Air cavity (slightly ventilated)AirR=0.09
Air cavity (well ventilated)Air-
SteelMetals50.000
AluminiumMetals160.000
Stainless steelMetals17.000
Carpet + underlayFinishesR=0.15
Timber flooringFinishes0.140
Vinyl/linoleumFinishes0.170
Ceramic tilesFinishes1.000

Values from BR 443: Conventions for U-value calculations. Always verify with manufacturer data where available.