Thermo ash
[Ther-mo-es-che] [Fraxinus spp.] [Trade names: Thermo Ash (EU)]
|
Origin |
Central Europe; thermally modified |
|
Raw density |
approx. 450-550 kg/m³ |
|
Durability class |
Class 1-2 |
|
Radial shrinkage |
approx. 2-3% |
|
Tangential shrinkage |
approx. 4-5% |
|
Wood color |
Dark brown due to heat treatment |
|
Wood structure |
coarse-pored, homogenized through modification |
|
Use |
Terraces, facades, furniture |
Origin and character of the wood
Thermo ash comes from ash trees(Fraxinus spp.) that originate from European or North American stands. Heat treatment at 160-215 °C under controlled conditions chemically modifies water-sensitive components in the wood. wood are chemically alteredwhich reduces moisture absorption.
Thermal finishing with costs
The thermo-modification process gives the ash a dark color and improves its durability. Its shrinkage and swelling behavior which makes it dimensionally stable and less susceptible to weathering. However, this advantage comes at a price: heat treatment changes wood components (hemicelluloses, lignin), cell walls are remodeled – this results in a certain brittleness and significantly reduces the mechanical strength. Applications that require high loads or punctual forces (e.g. by hammering in fastenings) should therefore be reconsidered.
A wood between benefit and caution
The ecological value depends heavily on the origin, forest management and the energy source of the treatment. The reduced strength and possible brittleness require careful planning, suitable fastening methods (e.g. screws instead of hammering in clips) and realistic expectations regarding durability and maintenance.
Sources:
pur natur – experiences with thermo ash,
EGGBI – research & overview,
Gartenhaus Magazin – advantages & disadvantages
from 9,80 €
Garapa decking boards, FSC 100%
Price from: € 65 per m2, resistance class: 1-2
Advantages: ✓ smooth surface ✓ homogeneous, light color
Disadvantages: ✗ Ferrous materials lead to discoloration ✗ Tendency to warp if not screwed down
Tip: patio cleaning removes discoloration and
professional interim storage prevents warping.
from 6,90 €
Teak decking boards, FSC 100%
Price from: € 130 per m2, resistance class: 1
Advantages: ✓ Best durability and dimensional stability ✓ Lowest risk of cracking and splintering
Disadvantages: ✗ Relatively expensive ✗ Not very long planks
Tip: Lay decking boards together.
from 11,85 €
Cumaru decking boards, FSC 100%
Price from: € 70 per m2, resistance class: 1
Advantages: ✓ best durability ✓ particularly robust and scratch-resistant
Disadvantages: ✗ Partly rough surface ✗ High force development
Tip: Sand the boards after the first weathering.
