Plaster Specs

Cement Based Options

Plaster can be colored with blue, green, charcoal, and other oxides. In addition, other cement based linings have entered the market using quartz or rock aggregate base. Limestone and dolomite pool mix has less permeability than quartz or silica aggregates. Diamond Brite is probably the most recognized brand, but there are several other choices.

Re-plaster Preparation

Surface preparation is the most important phase in the re-plaster process. A thorough surface prep assures good adhesion. Cheap shortcuts lead to problems. Mid-America Pool Renovation, Inc. uses a 40,000 PSI Hydro-Blast unit on most re-plastering preps to provide the strongest mechanical bond. “Scratch coats”,”bondcoats” or sandblasting alone cannot provide the same level of adhesion to the pool shell.

Both the International Concrete Repair Institute and the America Concrete Institute agree that Hydro-blasting offers many advantages over traditional preparation methods. Dust control, elimination of ‘micro-cracking’, and an ideal surface for bonding of the new surface are just a few of the benefits identified. “Scratch coats”, “bond coats”, or sandblasting methods will not provide the same level of adhesion to the pool shell.

When Hydro-Blasting is not able to be employed (high rise pools or limited access) Mid-America Pool Renovation, Inc. uses what is called the “axe-chipping method” for surface preparation.

An article in the Pool & Spa Service Industry News says the “axe chipping method” is the recommended method because it “creates a very rough jagged irregular surface without damaging the integrity of the structure of the pool. It removes loose plaster and allows the new plaster to bond mechanically to the surface.” In addition, all loose and hollow plaster is removed.

Included in the prep is saw-cutting and carefully chipping away the old plaster from below the old tile. Eliminating this step will leave an ugly algae-trapping plaster bulge under the tile. Some customers request complete removal of the previous plaster prior to resurfacing. This type of removal process greatly raises the cost of a re-surfacing and according to the Society for Protective Coatings (SSPC) and the National Association of Corrosion Engineers’ Surface Preparation specifications 4.3.3., as well as the Pool & Spa Service Industry News, jackhammering all the old plaster off the shell “can cause excessive trauma to the integrity of the pool shell and cause structural damage.”

Replaster prep for gunite pool
“Axe chipped” plaster prep

Replaster prep under tile
Saw-cut and chip below tile

New marcite flush with tile
New plaster flush with tile. No ugly bulge.

Plaster commercial pool with racing lanes
Re-plaster done by Mid-America Pool Renovation, Inc.