They aren't very well suited to carrying much weight, but there are three points of support. 1) When the slideout is extended, the inner edge of the slideout floor is resting firmly on the main floor. 2) The dual rack and pinion slide mechanisms support the outer edge of the slideout. 3) The top of the slideout lip is tight against the main wall, so that is the final support. Basically, extending the slideout tight at the bottom also forces the top against the main wall.
Texas Baptist Men-Retiree Builders member since '01
13 Silverado 3500HD D/A, 2wd CCSB srw, custom RKI bed
11 Cruiser CF32MK