The most important item to ensure the water tightness and longevity of your waterline tile and plaster finishes, is the coping that forms the seal at the top edge of the pool. It is very important that no water can penetrate from the outer side of the pool or the pool deck itself into the coping, eventually seeping into the tile and plaster. Water penetrating the coping, tiles or plaster will freeze, expand, thaw, freeze... and cause your tiles to fall off and your plaster to blister.
Natural Stone Coping
Currently, the most popular option is the setting of a variety of natural stones, with either rock-faced or bull-nosed edges. The stones are set on the levelled pool beam with a high-performance, freeze-resistant polymer-modified thin-set mortar. This method ensures a solid waterproof bond with the flexibility to handle Canada's vicious freeze-thaw cycle. A more conventional method that is often used by landscape companies for house patios and walkways, skips the bond beam repair and uses a basic brick layer’s mortar to build up and adhere the stones. While probably adequate for those applications, this should not be carried through to the pool beam that will be home to thousands of dollars of tile, plaster, and the coping stones themselves. Be sure, the pool coping is part of the pool structure and not the landscape. All stones are grouted with coloured, aggregated, hydraulic grout.
Pre-cast Concrete Coping
The second option is a variety of pre-cast concrete coping stones. These are more affordable than the natural stone, and come in a variety of styles including:
- natural stone replication (coloured, stamped concrete look),
- smooth finish bull-nosed or safety edge concrete in white or a variety of custom colours,
- and bull-nosed paving stone style in a variety of colours.
Poured Concrete Coping
The third option is a poured pebble-finish or coloured stamped concrete coping. This coping is actually attached into the pool beam with re-bar anchors, essentially becoming one with the pool. This option is often recommended when the beam is badly deteriorated, as it reduces the amount of beam re-building required, and is often the most economical choice.
This is a common complaint from homeowners who have had repair jobs on their waterline tile, or full re-tiling without proper attention and repair/replacement of the coping-which was the root of the problem to begin with.