IG pool step repair question


Apr 26, 2016
Seacoast NH
Hi, my 16x34 IG vinyl pool plastic steps developed a hairline crack. I read somewhere about injecting foam to take out some of the flex. I did patch the crack this summer.

I drilled holes in the steps to inject foam. It seems like there are two layers to the steps. The foam injection worked ok. My question is, why are there 2 layers? Is the inner, concealed layer the watertight portion and the exposed, white layer is just a cover? I drilled through both layers and am worried I really screwed this up.

I have started plugging the holes in the layer you walk on. I am using 1/8 npt SS socket head plugs so the will sit flush. Of course, I am tapping threads in the holes. Thanks for any insight!!