Hi Woodbloke
I'm working with the D4 (PU), it has better resistance to water and is suitable for external use.
I just Copy/Past
"Stress groups
The wood glues are divided in different stress groups, old designation DIN 68602 (B1, B2, B3 and B4) new designation DIN/EN204 (D1, D2, D3 and D4) the stress groups arrange the glues according to their minimum shearing strength values and their behavior under humidity and influence of water:
B1 or D1 - suitably for the internal area, whereby the wood moisture under 15% must remain.
B2 or D2 - suitably for the internal area with occasional brief water and/or condensation effect, whereby the wood moisture may reach maximally 18%
B3 or D3 - suitably for the internal area with frequently brief influence of water or higher humidity. Been suitable for the external area without suspension of a direct weathering
B4 or D4 - suitably for the internal area with frequent and long continuing effect of flowing off water and/or condensation. In the external area and the weather suspended with appropriate surface protection".
niki
