Hello! I am going to be repairing some cracked/chipped concrete around my skimmer and was hoping to get some input/advice. We had our pool built in 2006 and had troubles from the start with the construction of the concrete surrounding the skimmer. Our pool builder repaired this by patching the area with a masonry type of material. The repair now has cracks and some has chipped off. I wanted to repair it with a masonry filler but wasn't sure if it should be one specifically marketed for pools or if it needs to be waterproof? Also in that same area under the coping, there is a black tar like substance, that I believe is a waterproofing membrane? I noticed some gaps between the black membrane and the surrounding tile/concrete wall. I was planning on using a pool putty in this area? Any advice or input would be greatly appreciated!!