Other than the bedroom slide, ours are the black plywood, similar to what has been presented as delaminating. But, only our main slide (living room) has the edges exposed below the side wall trim. And it's only about 1/4" exposed and it is also coated black (sealer?) The kitchen and entertainment slides don't show the edges. I'm thinking if I just paint on a sealer annually, it should protect the edges without adding the aluminum angle. Mine made it extended through last summer without a problem. Looking at them the other day, they're still good as new.