Duo and trio beams
Duo and trio beams: two or three glued pieces for larger cross-sections than KVH – strength, common sizes, standard, uses.
glued solid timber
Two or three dried planks or squared timbers are glued together face to face, with the grain in the same direction. This produces a larger, more shape-stable cross-section than a single sawn beam.
How is it made?
The pieces are dried to no more than 15% moisture, the glued faces are planed and joined with MUF or PUR adhesive. The finished beam has a planed surface and chamfered edges; it is available in visible (Si) and non-visible (NSi) quality.
For load-bearing capacity it makes no difference whether the glue line is horizontal or vertical – if it matters for appearance, it must be specified in the order.
Technical data
- Build-up
- two or three planks or squared timbers dried to no more than 15% moisture, glued face to face
- Raw material
- usually spruce and fir; on request pine, larch or Douglas fir
- Strength
- C24 (bending strength 24 N/mm²)
- Density
- depends on the species – spruce 440–470 kg/m³
- Adhesive
- MUF or PUR (approx. 5 kg/m³)
- Common sizes
- width 60–240 mm, depth 100–240 mm
- Standard
- EN 14080
- What is it for?
- visible wall, floor and roof structures with larger cross-sections than KVH
| Width \ depth (mm) | 100 | 120 | 140 | 160 | 180 | 200 | 220 | 240 |
|---|---|---|---|---|---|---|---|---|
| 60 | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
| 80 | ○ | ○ | ○ | ● | ● | ● | ○ | ○ |
| 100 | ○ | ○ | ● | ● | ● | ● | ● | ● |
| 120 | ● | ● | ● | ● | ● | ● | ||
| 140 | ● | ● | ● | ● | ● | ● | ||
| 160 | ● | ● | ● | ● | ||||
| 180 | ● | ● | ● | ● | ||||
| 200 | ● | ● | ● | |||||
| 240 | ● |
● in visible and non-visible quality, ○ in non-visible quality only. A single piece is at most 8 cm thick and 28 cm wide (the pieces of a trio with vertical glue lines at most 12 × 10 cm).
Applications
- visible beams, rafters, columns
- where the cross-section of KVH is no longer enough, but glulam is not yet needed
What to watch out for
- Stock cross-sections go up to 240 × 240 mm; larger or stronger elements require glulam.
- In visible structures, the direction of the glue line is a question of appearance – it is worth specifying when ordering.