I have another question (please let me know if this should be in a separate thread). I'm going to try to attach photos, hopefully I do it correctly.
Does anyone know why this plastic plate would be installed under the slide carpet? It's only a little over a foot long and only in one area near the fireplace. If I lift it, I can see right down to the ground outside. It is not sealed at all. Is this normal? We just can't figure out what it is for.