CLT (Cross-Laminated Timber) represents a new era in timber construction. It is manufactured from kiln-dried solid wood layers (typically three, five, or seven), laid crosswise to each other and bonded with certified formaldehyde-free adhesives.
The crosswise arrangement of the layers creates panels with outstanding strength, stiffness, and geometric precision.
Each CLT panel is cut to your exact project dimensions, so you are charged only for the net square meters you need – not for the offcuts. This ensures full cost-efficiency with zero waste.
At the same time, panels are produced in large formats up to 3.5 m wide and 13.5 m long, the maximum size that can be transported by truck. This flexibility allows precise design solutions, fewer joints on site, and faster installation, while keeping logistics practical and efficient.
Below are the key technical specifications and properties of CLT panels, demonstrating their strength and versatility.
| Surface visual quality of XLAM DOLOMITI XLAM panels (ETA 12/0347) | |||
|---|---|---|---|
| Criteria | Industrial Quality (IQ) | Industrial Visual Quality (IVQ) | Visual Quality (VQ) |
| Surface processing type | Uniform without further processing | Planed or sanded | Planed or sanded |
| Color & texture | No special requirements | Very uniform | Uniform |
| Wood species | Possibility to include species beyond the primary spruce | Single species: Spruce | Single species: Spruce |
| Joint width between boards | < 3 mm | < 3 mm | < 2 mm |
| Knots | Allowed | Sound, tight knots allowed; black up to 35 mm; loose (fallen) up to 20 mm diameter | Sound, tight knots allowed; black up to 25 mm; loose (fallen) up to 10 mm diameter |
| Resin | Allowed | Small amount of resin permitted (up to 70 mm) | Small amount of resin permitted (up to 50 mm) |
| Repairs | Allowed | Allowed | Small amount allowed |
| Discolorations (blue stain / persistent red & brown streaks) | Allowed | Small amount allowed | Small amount allowed |
| Visible tunnels from inactive insects | Allowed | Small amount allowed | Not allowed |
| Bark inclusions | Allowed | Small amount allowed | Not allowed |
| Pith | Allowed | Allowed up to 1000 mm | Allowed up to 800 mm |
| Compression wood | Allowed | Allowed | Allowed |
| Decay | Not allowed | Not allowed | Not allowed |
| Finger jointing of outer boards | Allowed | Allowed | Allowed |
ETA-12/0347 includes all characteristics of XLAM DOLOMITI panels (strengths, moduli of elasticity, etc.).
| Example values from ETA tables | ||
|---|---|---|
| Property | Symbol | Value |
| Thermal conductivity | λ | 0.12 W/(mK) |
| Specific heat capacity | Cp | 1600 J/(kgK) |
| Recommended charring rate | — | 0.7 mm/min |
| Modulus of elasticity | ||
|---|---|---|
| Description | Symbol | Value |
| Mean modulus parallel to grain | E0,mean | 11,000 MPa |
| Characteristic modulus parallel | E0,05 | 7,400 MPa |
| Mean modulus perpendicular to grain | E90,mean | 370 MPa |
| Mean shear modulus | Gmean | 690 MPa |
| Strength values | ||
|---|---|---|
| Description | Symbol | Value |
| Bending strength | fm,k | 24 MPa |
| Tension parallel to grain | ft,0,k | 14 MPa |
| Tension perpendicular to grain | ft,90,k | 0.4 MPa |
| Compression parallel to grain | fc,0,k | 21 MPa |
| Compression perpendicular to grain | fc,90,k | 2.5 MPa |
| Shear | fv,k | 4 MPa |
Minimum board strength class C24 (reference UNI-EN338/2009).
Characteristic density: 350 kg/m³, mean density: 420 kg/m³.
| Geometric characteristics | |||||||
|---|---|---|---|---|---|---|---|
| Thickness Thickness [mm] |
Layers Layers |
Composition (layout) Laying-up |
Full section area Afull [mm²] |
Net section area Anet [mm²] |
Full second moment of area Ifull [mm⁴] |
Effective second moment of area Ieff [mm⁴] |
Ieff / Ifull % |
| 57 | 3 | 19-19-19 | 57 000 | 38 000 | 15 432 750 | 14 878 790 | 96.4 |
| 83 | 3 | 33-17-33 | 83 000 | 66 000 | 47 648 917 | 47 252 124 | 99.2 |
| 90 | 3 | 30-30-30 | 90 000 | 60 000 | 60 750 000 | 58 575 700 | 96.4 |
| 100 | 3 | 33-34-33 | 100 000 | 66 000 | 83 333 333 | 80 168 200 | 96.2 |
| 120 | 3 | 40-40-40 | 120 000 | 80 000 | 144 000 000 | 138 831 111 | 96.4 |
| 85 | 5 | 17-17-17-17-17 | 85 000 | 51 000 | 51 177 083 | 40 860 466 | 79.8 |
| 100 | 5 | 17-17-32-17-17 | 100 000 | 66 000 | 83 333 333 | 62 760 509 | 75.3 |
| 124 | 5 | 30-17-30-17-30 | 124 000 | 90 000 | 155 072 250 | 136 899 943 | 88.3 |
| 137 | 5 | 33-19-33-19-33 | 137 000 | 99 000 | 214 279 417 | 188 275 544 | 87.9 |
| 158 | 5 | 40-19-40-19-40 | 158 000 | 120 000 | 328 692 667 | 295 534 891 | 89.9 |
| 172* | 5* | 33-33-40-33-33 | 158 000 | 132 000 | 424 037 333 | 418 868 444 | 98.8 |
| 179 | 5 | 33-40-33-40-33 | 172 000 | 99 000 | 477 944 917 | 364 313 356 | 76.2 |
| 186 | 5 | 40-33-40-33-40 | 179 000 | 120 000 | 536 238 000 | 445 215 805 | 83.0 |
| 200 | 5 | 40-40-40-40-40 | 186 000 | 120 000 | 66 666 667 | 532 275 556 | 79.8 |
| 200* | 5* | 40-40-40-40-40 | 200 000 | 160 000 | 66 666 667 | 661 497 778 | 99.2 |
| 217 | 7 | 40-19-40-19-40-19-40 | 217 000 | 200 000 | 851 526 083 | 721 664 776 | 84.7 |
| 240* | 7* | 40-40-20-40-20-40-40 | 240 000 | 132 000 | 1 152 000 000 | 1 115 817 778 | 84.7 |
| 252 | 7 | 33-40-33-40-33-40-33 | 252 000 | 132 000 | 1 333 584 000 | 904 902 200 | 67.9 |
| 280 | 7 | 40-40-40-40-40-40-40 | 280 000 | 1 650 000 | 1 829 333 333 | 1 317 613 333 | 72.0 |
| 297 | 9 | 33-33-33-33-33-33-33-33-33 | 297 000 | 165 000 | 2 183 272 750 | 1 474 984 253 | 67.6 |
Thanks to its stability, it can support even multi-storey buildings, opening new possibilities in architecture.
In the Greek context, CLT is ideally suited to islands and mountainous regions, where transport and rapid erection are decisive.
Fill out the form and we will contact you for consultation.
6 & 7 December | Metropolitan Expo
We await you at the largest architectural event in Greece
to discover the future of timber construction with CLT up close!