The Specialist in Underwater Pool Repair

Don't Drain Your Pool !!

Pop Offs/ Delaminated Plaster

Plaster delamination is also known as a "Pop Off". A "pop off" is a piece of plaster that has 
broken away form the pool floor. They look like little moon craters.

Pop offs occur when cavities or voids form beneath a pool's plaster surface, despite the best efforts of the plasterer. Although this process is not completely understood, voids can be caused by a number of things, including plaster shrinkage, cracks, and hollow spots between pool fixtures and the plaster. When the void fills with water, a process is set in motion as the water mixes with calcium hydroxide that is in the plaster. This results in volcano-like bumps or mounds on the floors or walls of your pool, This is an indicator of delamination.

The plaster beneath these calcium bumps is delaminating. Eventually, the delamination breaks, leaving holes in the plaster with very sharp edges. Many people describe them looking like moon craters.

I find that most pop offs occur in replastered pools. Most of these pools are plaster over plaster. If the plaster company has not prepared the pool properly before replaster, pop offs are more likely! 
For this reason I prefer "chipping out" all existing plaster down to the gunite before resurfacing. There are companies in our area that will chip out and there are companies that will not. If you are replastering, be sure and ask!

Mike the Poolman can repair pop offs without draining your pool. I will cut out pop offs down to the gunite and patch to match your existing plaster.