To give your pool remodel the longest life span, you’ll want to ensure special attention is given to preventing plaster delamination.
Delamination refers to the blisters that appear on the surface of the swimming pool. It is damage that results in layers of the material separating from each other. Delamination is typically caused by impact or stress between or across the layers calcium-rich solute as it re-enters the pool through the fiberglass or plastered surface imperfection. Delamination, excessive craze cracking, or other similar defects allow water to get either behind or into the interior of the plaster mass and dissolve calcium hydroxide, which carbonates into a solid mass when it exits to the pool surface.
More common in re-plastered pools where newer surfaces are difficult to bond to the underlying surface, and bond failures can cause a void which can lead to the surface nodule formation. Smaller nodules may form on craze cracking that can result from an overly wet mix, an accelerated drying of the new plaster such as from excess calcium chloride (a set accelerant), or from environmental factors such as excessive heat, low humidity, wind, or excessive sun exposure before the pool is filled.
During a pool remodel, 90 percent of the time, delamination occurs when the plaster is not completely removed for the next, new layer of plaster. At Atlantis Pools, we completely remove all plaster on each remodel we do. Be wary of anyone trying to cut corners when it comes to plaster. Some installers may only sand blast or acid wash the old plaster and then add the new plaster on top of the old. That is a recipe for disaster and a shorter lifespan for the life of your new plaster investment.