Pool construction types in the UAE and what they mean for repairs

Why the type matters

A crack, a leak or a loose tile means different things in different pools. The repair materials, the risks and the skills needed all depend on how the pool was built. Knowing your pool type before you call a specialist saves a wasted visit and helps you judge whether the person quoting has done this kind of work before.

Concrete shells

Concrete pools are built on site, either sprayed (often called gunite or shotcrete) or cast, which allows almost any shape. The shell is then finished, usually with tiles or glass mosaic, or with a plaster or render finish.

Two points matter for repairs:

• Watertightness comes from the structure. UltraTileFix notes that pool construction is governed by codes for water-retaining concrete structures, that the construction must be inherently watertight, and that it should be tested before tiling starts. Tile adhesives and grouts are water resistant, but they do not stop water passing through.
• Membranes are system-specific. Some pools have a waterproofing membrane between shell and tiles. Its compatibility with groundwater conditions and with the adhesive above it depends on the manufacturer's system.

Typical repairs: tile and mosaic re-fixing, regrouting, crack repair, membrane renewal, resurfacing, and work on fittings set into the shell.

Fibreglass

Fibreglass pools are factory-made shells that are craned into place. The surface is a gelcoat.

Repairs to a fibreglass shell call for fibreglass skills rather than tiling skills. ARDEX's technical guidance shows how the two meet: tiles can be bonded at and just below the waterline of a fibreglass pool, but not at depth, and only after the gelcoat is mechanically roughened. Roughening that goes too far may compromise the integrity of the shell. ARDEX also warns against bonding coping tiles rigidly across the junction between the fibreglass shell and the surrounding deck, because the two move differently.

Typical repairs: gelcoat repair, crack repair, resealing fittings, and coping and waterline tile work.

Vinyl liner

A vinyl liner pool has a structural wall and floor with a flexible liner forming the watertight surface. The liner is a wear layer that can be replaced without rebuilding the pool.

Leak checks focus on the liner itself. LeakTronics' dye testing guidance singles out seams, corners and the area around every fitting in vinyl liner pools.

Typical repairs: liner patches, resealing faceplates and fittings, and full liner replacement.

Stainless steel

Stainless steel pools are assembled from engineered panels or welded into a continuous structure. Natare, one manufacturer, offers an all-welded system and a structural panel system. It lists elevated and rooftop pools, new construction and the renovation of ageing concrete pools among their uses, with finishes including polished stainless steel, PVC membrane lining and ceramic tile.

Repairs need a specialist familiar with the specific system, whether the job is welding, membrane work or tiling over steel.

Skimmer pools and overflow pools

The construction material is only half the picture. How the water level is managed matters just as much.

Skimmer pools

The water sits a little below the edge, and skimmers in the wall draw surface water to the pump. The seam where the skimmer body meets the shell is one of the first places LeakTronics' dye testing guidance tells technicians to check.

Overflow and infinity pools

The water spills over an edge into a perimeter gutter or a catch basin and flows to a balance tank (also called a surge tank), from which it is pumped back through the filtration. The tank absorbs the water displaced when people get in and out.

The U.S. Model Aquatic Health Code, a CDC guidance document for public pools, gives a useful picture of what a balance tank should have: defined minimum, maximum and normal operating levels marked on the tank, and overflow pipes that carry excess water to waste through an air gap. The balance tank, the gutter, the level controls and the automatic top-up are all places where faults and leaks occur.

For leak detection, the water to watch in an overflow pool is usually in the balance tank, not on the pool wall.

Rooftop and podium pools

Pools on roofs and podiums sit above occupied space, plant rooms or car parks. Any leak can reach the structure below, so investigation should start promptly and involve building management from the beginning. Access to plant rooms and to the space below the pool is part of the job, and the waterproofing beneath the pool is often a separate layer from the pool finish.

How to work out what you have

• Look at the surface. Tiles or mosaic throughout suggest concrete (or tiled steel). A smooth one-piece shell suggests fibreglass. A soft surface with visible seams suggests a vinyl liner.
• Look at the edge. Water level below the edge with skimmer openings means a skimmer pool. Water at or over the edge means an overflow or infinity pool with a balance tank.
• Check the paperwork. Handover documents, warranties and approved drawings usually state the construction type, and drawings often show the pipework and equipment as well.

If you are still unsure, say so when you contact a specialist and send photos of the surface, the edge and the plant room.