dasso.CTECH®
CTECH Joists
Ultra-stable bamboo joists — the structural backbone of a durable dasso.CTECH® deck.
Advantages of dasso.CTECH®
Fire resistance
Decking reaction to fire: Class Bfl-s1 (EN 13501-1)
Cladding reaction to fire: Class B-s1,d0 (EN 13501-1)
Mould resistance
Class 0
[DIN EN ISO 846: 1997-10] [DIN EN 152: 2011]
Termite resistance
Reticulitermes santonensis
DC D (durable) [EN 117]
Environmentally friendly
Negative carbon footprint over its full life cycle.
See our Environmental Product Declarations (EPD).
Hardness & durability
Durability Class 1 (EN 350:2016)
Use class 4 (EN 350 – EN 335)
Warranty
25-year warranty for residential and commercial applications.
Gallery
Product in situ
4 photos · click to enlarge
About CTECH®
dasso.CTECH® joists are the load-bearing substructure engineered to match the performance and longevity of dasso.CTECH® decking. Densified thermally-treated bamboo, calibrated to a perfectly straight geometry with no knots.
Where tropical hardwood joists (Badi, Niove, Masaranduba) shrink between 6 % and 9.4 % over time, CTECH joists stay dimensionally stable at 0.6 %. The result: no twisting, no cupping, no callbacks — a substructure engineered to outlive the deck itself.
Key features
- 25-year warranty — matching CTECH decking
- Ultra straight geometry, no knots, no defects
- Ultra stable — 0.6 % shrinkage
- Density > 1200 kg/m³
- Class 4 durability (ground/wet exposure)
- Consistent 3050 × 60 × 40 mm sections
Technical — Sizing
Maximum support spacing — CTECH joists on 3 supports
Source: French Avis Technique — Table 8. Maximum span (mm) between supports for CTECH joists in a 3-support configuration, under a waterproofing-protection decking layer.
| Usage category | Distributed load (kN/m²) | Concentrated load (kN) | 60 × 40 (b×h) | 40 × 60 (b×h) |
|---|---|---|---|---|
| A — Residential terrace | 1.5 | 2 | 540 mm | 780 mm |
| A — Stairs | 2.5 | 2 | 540 mm | 780 mm |
| A — Balconies | 3.5 | 2 | 540 mm | 780 mm |
| C1 — Cafés / restaurants | 2.5 | 3 | 450 mm | 660 mm |
| C3 — Circulation, no obstacles | 4 | 4 | 390 mm | 580 mm |
| C5 — Areas subject to crowds | 5 | 4.5 | 370 mm | 550 mm |
Technical — Comparison
CTECH joists vs. tropical hardwood joists
Head-to-head comparison of CTECH bamboo joists with the tropical hardwoods most commonly used for deck substructures (Badi, Niove, Masaranduba).
| Property | Badi | Niove | Masaranduba | dasso.CTECH® |
|---|---|---|---|---|
| Dimensions | Variable | Variable | Variable | 3050 × 60 × 40 mm |
| Warranty | — | — | — | 25 years |
| Density | 760 kg/m³ | 880 kg/m³ | 1100 kg/m³ | 1200 kg/m³ |
| Shrinkage | 7.50 % | 6.00 % | 9.40 % | 0.6 % (Ultra Stable) |
| Durability class | Class 4 | Class 4 | Class 4 | Class 4 |
