Sections of fiberglass matting, which is thin enough to read through, are then cut from large rolls and laid on top of this fresh resin coat while it is still damp, forming a bond. Unlike PVC, where sections wharf wood postsare laid to overlap, sections of fiberglass matting butt up against one another and are sealed by a second coat of resin. As this resin is rolled on, it is forced to penetrate the fiberglass mat, creating a bonded sandwich of resin around fiberglass. This step building a deck over a small patio for cheapalso helps remove air pockets and shape the fiberglass to the contours of the pool. This surface is sanded by hand to remove any sharp points, and a third coat of resin is applied, leaving a nonporous outer surface. Fiberglass matting, proponents argue, allows the pool's interior to be covered with a plastic wood studconsistent thickness of renovation material, which including all resin layers amounts to about an eighth of an inch.