Beams and panels specifically designed to meet the needs of the most demanding customers in the construction industry

50 years of service and to meet the needs of the most demanding customers in the construction industry.

General information

Gbm beam H20 and Gbm beam H20+ are the strongest and lightest formwork beams made of engineered fir and spruce wood. Our formwork beams are produced in various standard lengths. With Chords made of high-quality and graded massive finger-jointed timber, Webs made with a 3-ply laminated wood panels and optional protective cap that prevents the beam to be exposed to premature chipping on the chord ends, Gbm beam H20 and Gbm beam H20+ assure sustainability and durability in all climate zones.


  • - Product: Wooden formwork H20 beams
  • - Wood species: Spruce, fir
  • - Wood moisture: 12 % +/- 2 % at delivery
  • - Weight: 4,5 kg/m
  • - Gluing: Melamine resin-based adhesive, adhesive type I EN 301-approved for gluing of load bearing timber components
  • - Surface protection: The beam is waterproofed using a water repellent color glaze
  • - Chord: Made of carefully selected spuce wood; Finger-jointed, solid wood cross-sections with a dimension of 80x40 mm; Finger-jointing of the chords; Web milling on the opposing side of the core (left-sided chord surface); Planed and chamfered to approx. 0.4 mm
  • - Web: 3-ply solid wood panel, laminated primarily showing vertical growth rings
  • - Surface protection: Treatment of entire beam using a water-resistant color stain

Support: Due to the 3-ply solid wood webs, Extrabeam H20 and Extrabeam H20+ can be cut into and supported at any length.

Dimension Value (a) Tolerance (b)
Beam height 200 mm ± 2 mm
Chord height 40 mm ± 0,6 mm
Chord width 80 mm + 0,8 mm/-1,2 mm
Web thickness 28 mm ± 1 mm

a) These values apply at a wood moisture content of 12 % ± 2%
b) According to standard SIST EN 13377:2002

Qualities DIN1052-1:1988-04 DIN1052:2008-12 / Eurocode 5
Strains Permissible stress values Characteristic limits of load-bearing capacity
Shearing force ZUL Q = 11,0 kN Vk = 23,9 kN
Bending moment ZUL M = 5,0 kNm Mk = 10,9 kNm
Support - Rb,k = 47,8 kN
Section modulus (1) Wx= 461 cm3
Geometrical moment of inertia (1) Ix= 4.613 cm4
Elasticity modulus E = 10.000 N / mm2
Shearing modulus G = 600 N / mm2

The values of the section modulus and the geometrical moment of inertia apply to new or used concrete formwork beams. An analogously increased factor of safety needs to be added for severely worn beams.

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