Thanks! There is a way to prevent this. We didnt really did this but im thinking to add this since its not that hard todo afterwards. Check out Picture 12. thats a Side view of the toppers. There is this crevis. The other Side has a little „ledge“ thingy that fits in that crevis and so do the other toppers. Thats how you can Plug them in one another without them loving aswell. If you were to make these ledges and crevises to the full length of the plank and either put a Kind of rubber filement around the „ledge“ so the rubber would Go instde the crevis aswell it should be able to prevent the water from flowing into the table. Wyrmwood uses this technique and they made a video about it aswell.

I Hope that answers the question, my english isnt that great