The first piece of wall molding went up on the south wall of the crew quarters. I had to set my laser on the scaffold in order to project a line 8 foot above the floor. If one looks carefully, you can see the reddish colored line (but it is difficult). I used screws instead of nails/tension pins in fastening the edge molding to the wall. Once the first piece was up, it was just a matter of "working around the room". I found myself constantly checking with a digital level and measuring from the floor. The poured concrete floor was not ABSOLUTELY level, at all places. In one spot it was out of level by around 1/8 inch.