The durability class of wood tells something about the expected life of the wood. The strength class of wood tells something about the maximum load. At Regge Hout we set high standards for the durability class of our wood. Good quality hardwood results in a durable and functional end product. Many of our woods are also selected based on the strength of the wood. In various applications a high strength class of the wood is a requirement for the quality of the construction. By selecting wood species based on these two classes, we can guarantee quality and durability.

Sustainability class wood

The sustainability class of wood varies from 1 to 5, in which 1 is very sustainable and five not sustainable at all. Azobé, according to the sustainability class wood table, is located in class 1. This is very sustainable wood and very suitable for civil engineering purposes. Robinia is located in sustainability class 1-2 and with that, it is the most sustainable type of European hardwood.

In the following table, the sustainability classes are listed.

Class	Sustainability	Lifespan
1	Very sustainable	+ 25 years
2	sustainable	15-25 years
3	Sufficiently / moderately sustainable	10-15 years
4	Little sustainable	5-10 years
5	Not sustainable	< 5 years

Strength classes wood
For wood in architectural constructions, calculations according to building regulations are necessary. For this we use strength classes of the relevant wood species. The strength class for wood is an important property that gives a good indication of how strong a type of wood is. This strength class gives a good idea for which constructions the wood type is suitable. The strength class is indicated by the letter C for softwood and D for hardwood, followed by a number (e.g. C18), which corresponds to the representative value for the bending strength parallel to the fibre.

Examples of strength classes for structured wood, according to the NBN EN 338 standard

Examples of strength classes for structured wood, according to the NBN EN 338 standard
Property	Strength class
	Softwood					Hardwood
	C16	C18	C24	C30	C40	D30	D40	D50	D60	D70
Bending resistance [N/mm²]	16	18	24	30	40	30	40	50	60	70
Axial compressive yield strength [N/mm²]	16	18	21	23	26	23	26	29	32	34
Average axial elasticity modulus [kN/mm²]	8	9	11	12	14	10	11	14	17	20
Average voluminous mass [kg/m³]	370	380	420	460	500	640	700	780	840	1080
Visual class	S4	S6	S8	S10	–	–	–	–	–	–

There are many types of wood, all of which have their own unique properties, concerning the strength class and sustainability class. This makes that there will always be a suitable type of wood, for every utilization.

Our sales team has a lot of knowledge and is very willing to help you select the right type of wood. They can think along about the best solution. Call us on +31 547 286 350 or reach us by filling out the form on the right.