Balcony & Terrace Waterproofing

A balcony or terrace is a small area, but it is one of the most common sources of leaks in a building. The balcony is exposed to the full force of the rain, it is often not drained correctly, and it is usually tiled directly onto the screed without a waterproofing membrane. The water that sits on the balcony finds its way through the tiles and the grout, into the screed, and then through the slab into the room below.

The first step is to understand the balcony. We need to know the structure of the balcony, the falls, the drainage, and the condition of the surface. We also need to know what is on the balcony — the tiles, the screed, the waterproofing — and whether the waterproofing is the original or whether it has been repaired before.

The waterproofing of a balcony is a liquid-applied membrane that is applied to the prepared screed, and it is carried up the walls and the upstands to a height that is above the level of the water. The membrane is detailed at the drain, the threshold, and the penetrations, and it is tested with a flood test before the tiles are laid. The membrane is the waterproofing — the tiles are just the finish.

The drainage is the most important part of the balcony. The balcony has to fall to the drain, and the drain has to be connected to the waterproofing so that the water is carried away. If the balcony is not falling correctly, the water will sit on the surface, and it will find its way through the membrane. We correct the falls, we set the drain, and we make sure the water is carried away.

We also look at the details. The threshold of the balcony door is a common point of water ingress, and the junction between the balcony and the wall is another.

We detail these points with the membrane and the sealant, so the water is stopped at the surface.

The result is a balcony that is waterproof, a balcony that is drained, and a balcony that is protected. We document the system, we provide the specification, and we stand behind the work.