Unit Weight of Construction Materials

Unit weight or density is used to quantify the weight per unit volume of an object. When it is expressed in the basic SI Unit of mass (kg/m3), it is usually referred to as density, but when expressed in terms of weight (kN/m3), it is usually referred to as unit weight.


Density (kg/m3) = Mass (kg)/Volume (m3)

The unit weight of a material is very important in calculating the self-weight of the material, especially when evaluating the permanent actions in a structure. Without the knowledge of the unit weight of a material, it will be impossible to accurately estimate the bodyweight and the load it subsequently carries when used as a structural member. This article is dedicated to providing a handy list of the unit weight of various construction materials according to EN 1991-1-1:2002.

The density of a material can vary depending on the composition, process of manufacturing, and other factors. However, the density of man-made products is fairly constant (or controllable) when compared with the density of direct products of nature. Therefore, natural materials are expected to have slightly different properties even when they are occurring in the same place.

(a) Unit weight of concrete and mortar

MaterialsDensity (kN/m3)
Hardened normal weight concrete24.0
Reinforced concrete (normal percentage)25.0
Fresh concrete25.0
Cement mortar19.0 to 23.0
Gypsum mortar12.0 to 18.0
Lime-cement mortar 18.0 to 20.0
Lime mortar12.0 to 18.0

(b) Unit weight of natural stones

Natural StoneUnit weight (kN/m3)
granite, syenite, porphyry27.0 to 30.0
basalt, diorite, gabbro27.0 to 31.0
tachylyte26.0
basaltic lava24.0
gray wacke, sandstone21.0 – 27.0
Dense limestone20.0 – 29.0
other limestone20.0
volcanic tuff20.0
gneiss30.0
slate28.0

(c) Unit weight of timber and timber derived products

Timber/timber derived productUnit weight (kN/m3)
timber strength class C143.5
timber strength class C224.1
timber strength class C304.6
timber strength class D306.4
timber strength class D507.8
timber strength class D7010.8
homogeneous glulam GL24h3.7
homogeneous glulam GL32h4.2
combined glulam GL24c3.5
combined glulam GL32c4.0
combined glulam GL36c4.2
softwood plywood5.0
birch plywood7.0
laminboard and blockboard4.5
chipboard7.0 to 8.0
cement-bonded particle board12.0
flake board, oriented strand board, wafer board7.0
hardboard, standard and tempered10.0
medium density fibreboard8.0
softboard4.0

(d) Unit weight of metals

MetalUnit weight (kN/m3)
aluminium27.0
brass83.0 – 85.0
bronze83.0 – 85.0
copper87.0 – 89.0
cast iron71.0 – 72.5
wrought iron76.0
lead112.0 – 114.0
steel77.0 – 78.5
zinc71.0 – 72.0

(e) Unit weight of glass and plastics

MaterialUnit weight (kN/m3)
Broken glass22.0
Glass in sheets25
Acrylic sheet – plastic12.0
polystyrene, expanded, granules0.3
foam glass1.4
Terracota (solid)21
Cork (compressed)4

(f) Unit weight of asphalt/pavement materials

MaterialUnit weight (kN/m3)
gussasphalt and asphaltic concrete24.0 – 25.0
mastic asphalt18.0 – 22.0
hot rolled asphalt23.0
sand (dry)15.0 – 16.0
hardcore18.5 – 19.5
Quarry dust14.1

(g) Roofs and roofing materials

MaterialWeight per unit area (kN/m2)
Steel roof trusses in spans up to 25 m1.0 – 2.0
Corrugated asbestos-cement or steel sheeting, steel purlins etc.0.4 – 0.5
Roofing felt and screed2.0
Patent glazing (with lead-covered astragals), steel purlins etc.0.4
Slates or tiles, battens, steel purlins etc.0.7 – 0.9
Plain roofing tiles0.6 – 0.9
Interlocking roofing tiles0.6
0.45 mm gauge aluminium roofing sheet0.014

(h) Block works, brick works, partitions, and wall finishes

MaterialWeight per unit area (kN/m2)
225 mm block work2.87
150 mm sandcrete block work2.15
Wall finishes (both sides)0.6
12 mm plaster rendering0.3
Two-coat gypsum 12 mm thick0.215
Plasterboard 13 mm thick1.1
Gypsum panels 75 mm thick4.4
Clay hollow block0.0113 / mm thick
Common clay blocks0.0189 / mm thick
Engineering clay bricks0.0226 / mm thick
Refractory bricks0.0113 / mm thick

(i) Floor finishes

MaterialWeight per unit area (kN/m2)
Clay floor tiles0.575
25 mm thick terrazo floor0.6
37 mm thick screeding0.8
Terrazo paving0.0222 / mm thick
6 mm thick glazed tile + adhesive0.181
8 mm thick glazed tile + adhesive0.214
10 mm thick glazed tile + adhesive0.246
10 mm thick porcelain floor tiles + adhesive0.275
8 – 10 mm thick vitrified floor tiles + adhesive0.215
10 mm thick granite floor tiles + adhesive0.346
12 mm thick granite floor tiles + adhesive0.4
20 mm thick granite floor tiles + adhesive0.622

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