If your balcony is leaking to a room downstairs or even worse a neighbour, the most likely cause is failure of the waterproofing membrane (or in cases the absence altogether). If you’re lucky, it could be something else however this is very unlikely.

The very first step is to arrange a specialist leak detection company to ascertain what the cause is and verify it. Do not engage a plumber to do this unless they are specialist leak detectors as they are not specialists in this area. We can recommend a few leak detection companies who are great at what they do and provide comprehensive detailed reports. A few hundred dollars for a leak detection can save you thousands. You don’t want to complete a full balcony renewal when you don’t need to.

Once the leak detection report confirms waterproofing failure you have a few options. At Cornerstone Property Group we only recommend and conduct full balcony renewals to ensure the issue won’t happen again and the job is done properly. We don’t do patch or repair jobs as these never address the root cause and can lead to bigger problems down the track.

Option 1 – Full renewal of balcony (recommended) from $15,000 for a small balcony

This involves removing all the tiles and waterproofing back to the concrete slab or in the case of timber sub-floors the flooring right back to the timber floor joists. The area is then re-sheeted in external grade sheet flooring, waterproofed in accordance with AS4654, tiled and grouted (we always recommend epoxy grout for added waterproofing). If it is on a slab the slab is prepared and then waterproofed in accordance with AS4654, screeded (to generate the required drainage falls) and then waterproofed again in accordance with AS4654, tiled and grouted.

Option 2 – Epoxy Grout

Sometimes if the grout has decayed (common issue as budlings move and grout is cement based) this lets water in under the tiles and thus leaking below. But remember and be aware! The job of your waterproofing membrane is to stop the above, so if someone says the leak is because of the grout decay they are correct to a degree and you should ask “but if that is the case shouldn’t the waterproofing membrane prevent the water from leaking below” as the answer is YES! You can remove the grout and then re-grout the balcony with an Epoxy grout (a lot of companies will recommend this, you may have heard some on the radio or TV, we DON’T). Epoxy grout is an impermeable product and is waterproof in itself (won’t stain, discolour and let any water in and is also elastic meaning it can withstand some building movement whereas normal cementitious grout can’t). The major reason why we don’t recommend this is because it’s not addressing the root cause (that the membrane has still failed) and you can’t possibly dry out the sub-floor of water, so what is happening in your ceiling? This is going to decay timber members rotting them until you have structural problems (big cost). Your plaster ceiling is going to go mouldy, need replacing and create Health hazards!

The above is why we don’t recommend this. We understand some customers can’t afford to do a full renewal right now and this should only be used as a short-term fix until you can afford to do it properly.

The above will set you back anywhere from $2,500+.

Option 3 – UV Resistant Membrane

Similarly to the above and only for a temporary fix until the job can be done properly, an expert can prepare and waterproof over the top of the existing tiles to prevent further leaks. This would be slightly cheaper than the epoxy option however it will look ugly and it is not recommended to put furniture on it, foot traffic will be fine.