The law of the water column - function of section lines
In designs that require the overlapping of several bricks, the following should be taken into account: due to the increased pressure of the water column, the water in the bricks runs
downwards. This causes the upper bricks to drain towards the lower bricks. In the latter, the excess water then leads to drainage. This undesirable effect can be minimized by placing foil or even a thin layer of dry foam between the individual bricks, thus interrupting the water column. This ensures that sufficient water is stored in both the upper and lower bricks. Several, especially large OASIS® plug-in foam products are equipped with “cut lines” (narrow recesses in the foam) to interrupt the water column so that drainage is minimized.