In this step we build a frame of wooden Douglas beams. In our design above we added a double row of beams on the edges of the frame to increase the support for the walls. The cement-bonded particle boards are not meant to carry a lot of weight. Therefore we first placed this outer row of wooden beams loosely in place so we could mark their location with pencil onto the CBP boards. Afterwards we removed them and used a circular saw to cut this outer area from the CBP boards. Next we started building the inner frame with 155x63mm Douglas beams that where spaced around 400mm heart to heart on the CPB boards. We later added 175x63 Douglas beams on the outer edges and used clamps to level them on the top before screwing them together.
Next we started screwing the CBP boards to the inner frame from below. Because of the difference between the 155x63mm and 175x63 beams (175-155mm = 20mm ⇒ 2 mm difference with the 18 mm CBP boards) the CBP boards are slightly lifted from the steel deck while screwing them to the inner frame. This means the outer Douglas beams are now the only thing in direct contact with the steel deck and thus the weight of the house is transferred through these beams onto the steel deck.
