Europe
Thermally Modified Ash
Fraxinus excelsior (TMT)

- Density
- 620 kg/m³
- Bending strength
- 76 N/mm²
- Stability
- High
- Carbon stored
- 0.88 t CO₂e/m³
- Durability
- DC 1–2 after modification
- Service life
- 30–50 yrs façade
- Fire performance
- Euroclass D-s2,d0 (B achievable treated)
- Cost index
- 86
The figures above are Wood Intelligence editorial estimates for orientation only. Where a standards-referenced record exists for this species, it is shown below with full provenance.
Standards-referenced record
Thermally Modified Ash, as the standards define it
Each value below carries its derivation and the standard it comes from. Tap a marker to open the provenance.
- Density at 12 % MC
- 620kg/m³
- Natural durability
- DC 2
- Use classes untreated
- UC 1–3 untreated
- Reaction to fire
- D-s2,d0
- Design charring rate
- 0.5mm/min
- Biogenic carbon stored
- 1000kg CO₂e/m³
ProvenancemeaMeasuredpubPublishedderDerivedestModel estimate
Colour ageing
Deep coffee → grey in 18–30 months
Typical applications
- Façade
- Decking
- Cladding in humid climates
AI recommendation
Thermal modification removes the sugars that feed decay, making this a strong choice for humid subtropical and Gulf climates. Accept reduced impact strength.