The latest in my ongoing addition saga is the windows. It seems to me that putting in a good window is rather straightforward—level and square, protection against water infiltration, and pop it in. Well, I'm learning there may be more to this. We purchased sliding windows for the new addition—more in keeping with the modern design and lets lots of air in. The problem is the concentration of weight where the two sash meet. Instead of being distributed horizontally across the opening, there's a huge weight concentration where they meet and latch, in the middle. Without bracing underneath, the support bows, which makes the sash slip out of alignment and kind of tip sideways a bit. Solution: take off the trim and brace underneath or... install it right the first time!