EN 14080:2013· Europe

GL20h

Homogeneous glulam: bending 20 MPa, E0,mean 8 400 MPa, ρk 340 kg/m³.

Homogeneous glulam: all lamellas of the same strength class.

All values

Mechanical 13
Design values 14
Physical 2
Moisture and transport 1
Thermal 1
Fire 2
Chemical and durability not yet

Mechanical

Elastic

Modulus of elasticity parallel to grain E0,mean

Mean value, for deformation calculations.

Condition	Value	Evidence
	8 400MPa	Single source

Shear modulus Gmean

Mean value, for deformation calculations.

Condition	Value	Evidence
	650MPa	Single source

Modulus of elasticity, 5th percentile E0,05

Parallel to grain. Used for stability (buckling, lateral torsional buckling).

Condition	Value	Evidence
	7 000MPacharacteristic	Single source

Modulus of elasticity perpendicular to grain E90,mean

Mean value, for deformations across the grain.

Condition	Value	Evidence
	300MPa	Single source

Modulus perpendicular to grain, 5th percentile E90,05

Characteristic value across the grain.

Condition	Value	Evidence
	250MPacharacteristic	Single source

Shear modulus, 5th percentile G05

Characteristic shear modulus, for stability checks.

Condition	Value	Evidence
	540MPacharacteristic	Single source

Strength

Bending strength fm,k

Characteristic bending strength.

Condition	Value	Evidence
	20MPacharacteristic	Single source

Tension parallel to grain ft,0,k

Characteristic tensile strength along the grain.

Condition	Value	Evidence
	16MPacharacteristic	Single source

Compression parallel to grain fc,0,k

Characteristic compressive strength along the grain.

Condition	Value	Evidence
	20MPacharacteristic	Single source

Shear strength fv,k

Characteristic shear strength.

Condition	Value	Evidence
	3.5MPacharacteristic	Single source

Tension perpendicular to grain ft,90,k

Characteristic tensile strength across the grain; small, so details avoid it.

Condition	Value	Evidence
	0.5MPacharacteristic	Single source

Compression perpendicular to grain fc,90,k

Characteristic compressive strength across the grain: governs bearing at supports.

Condition	Value	Evidence
	2.5MPacharacteristic	Single source

Rolling shear strength fr,k

Shear in the plane across the grain (fibres rolling over each other).

Condition	Value	Evidence
	1.2MPacharacteristic	Single source

Design values

Modification factor for load duration and moisture kmod

Multiplies characteristic strength: fd = kmod · fk / γM. Wood is weaker under long-lasting loads and when wet.

Condition	Value	Evidence
	0.6	Single source
	0.5	Single source
	0.7	Single source
	0.55	Single source
	0.8	Single source
	0.65	Single source
	0.9	Single source
	0.7	Single source
	1.1	Single source
	0.9	Single source

Deformation factor (creep) kdef

Final deformation = instantaneous × (1 + ψ2 · kdef) for quasi-permanent loads.

Condition	Value	Evidence
	0.6	Single source
	0.8	Single source
	2	Single source

Partial factor for the material γM

Recommended value; each country may set its own in the National Annex (a Nationally Determined Parameter).

Condition	Value	Evidence
	1.25	Single source

Physical

Characteristic density ρk

5th-percentile density.

Condition	Value	Evidence
	340kg/m³characteristic	Single source

Mean density ρmean

Mean density.

Condition	Value	Evidence
	370kg/m³	Single source

Moisture and transport

Swelling and shrinkage across the grain αu,90

Change in cross-section dimension per 1 % change in moisture content.

Condition	Value	Evidence
	0.24% per % moisture	Single source

Thermal

Thermal conductivity λ

Heat flow through 1 m of material per kelvin of temperature difference.

Condition	Value	Evidence
	0.13W/(m·K)	Single source

Fire

One-dimensional charring rate β0

Charring depth per minute of standard fire exposure on one face.

Condition	Value	Evidence
	0.65mm/min	Single source

Notional charring rate βn

Includes the effect of corner rounding and fissures; used with the reduced cross-section method.

Condition	Value	Evidence
	0.7mm/min	Corroborated

Sources here are public pages that reproduce EN 14080:2013. For design and acceptance, the standard edition named in your specification and the CE marking and Declaration of Performance of the delivered product take precedence. Design factors are recommended values; your National Annex may set others.