Ok. Understood. That is bad for Karbol. Unfortunately, you just have to protect it with Konsolan or something like that. But it is quite a protected place anyway.
With the stringer, you do this because in the area where wood meets wood, moisture always accumulates and it then rots quickly. So a piece of roofing felt in between. Works wonders.
You do this on the jetty because in the area where wood meets wood moisture always lingers and it quickly rots there. So a piece of roofing felt in between. Works wonders.
I also found this, what do you think of something like that?
It would be enough to paint the top side of the beams, then roofing felt and the pads for height buildup in between. Screw the battens onto the beams and then the decking onto the battens.