For this model, the chosen floor area is 110 cm horizontal by 66 cm vertical. The wooden battens used have a section of 44 mm by 22 mm. The thickness of the frame is 44 mm. The frame is assembled with screws. At about 10 centimeters from the bottom of the frame, a cleat is added, as can be seen in the picture. It makes it possible to stiffen the frame, to stretch the sheet and to separate the freshwater and seawater parts (no risk of salt contamination).