Duo/trio beams | Services

Duo-/trio beams are laminated wood beams consisting of two or three individual wood elements glued against each other. Their one or two colourless glue joints hardly disturb the solid wood appearance. Duo-/trio beams are produced in KVH® quality and has even higher quality requirements in the areas of crack formation and dimensional stability. The quality of duo-/trio beams is equally good because of a quality-controlled production with defined properties. Those properties make duo/trio beams a calculable building material.

Our results regarding duo/trio beams

Merkle Holz offers:

Standard stock of visual quality in 13 metres available any time.
Up to 18 metres length available.
Large raw material stock for always short delivery times at special orders.
Duo-/Trio beams produced by list.
Visual quality is produced from preplaned and presorted material.
Standard Si dimensions also available in high-quality nordic spruce.
Machined structures ready for installation.
Special requests such as impregnation, millimetre severing or profil planing.

Requirements: Quality criteria of duo/trio beams

Other properties see KVH®.

Sorting feature	Requirements on
	Duo-/Trio beam-Si visual quality	Duo-/Trio beam-NSi industrial quality
Sorting class	C24 according to DIN EN 14081-1 with DIN 20000-5
Dovetail joint	DIN 68140-1 or DIN EN 385
Technical rules	Approval by the supervisory authority for buildings Z 9.1-440
Elasticity module II to grain	E_o,mean = 11600 N/mm²
Timber moisture	max. 15%
Dimensional accuracy of the cross section	DIN EN 336, Dimensional tolerance class 2 ≤ 10 cm ± 1.0 mm ≥ 10 cm ± 1.5 mm
Cracks, radial shrinkage cracks (drying cracks)	Crack width b ≤ 2% of the related cross-section width, max. 4 mm	DIN 4074-1
Longitudinal warping / Twisting	= 4 mm/2 m
Processing the ends	Cut at right angle
Surface condition	planed and chamfered	Levelled and chamfered