7 Ways to Repair a Leaking Balcony

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Although balconies are generally quite resilient, they can spring leaks if not properly maintained. A balcony leak might seem like more of a problem for your downstairs neighbors, but it could lead to numerous long-term structural issues for you, too.

Below, we’ll cover how to repair a leaking balcony. Provided it’s not a massive job, you can do it yourself, so read on to find out how.

Identifying the Cause of the Leak

The first step will be to identify why your balcony is leaking, if possible. There are numerous reasons why this might have happened, but the most common are:

  • Structural movement
  • Bad design/drainage
  • Membrane failure
  • Wear and tear
  • Broken balcony surface
  • Weather damage

Of course, not all of these are fixable with DIY. As such, we’ll focus on addressing easy issues like wear and tear, broken surfaces, and minor structural movement.

How to Repair a Leaking Balcony

1. Liquid Rubber

Liquid rubber (such as this) is a pretty self-explanatory product. It’s a waterproofing product that’s primarily used on flat roofs or gutters, but nothing is stopping you from using it on your leaky balcony.

It’s ideal for painting over joins between the balcony flooring and building or around other areas that might be letting water in. While you could paint the entire floor with it, it won’t look amazing if you do.

2. Waterproof Sealant

A better option for coating an entire floor is waterproof sealant (such as this). It works on porous surfaces like brick, tiles and concrete without affecting the color or finish. As such, it’ll stop water from soaking into the floor.

However, this could lead to other problems, such as water pooling on the floor surface. If this happens, make sure you have suitable drainage to get rid of the water. Be aware, too, that liquid sealant might not be compatible with all surface types or finishes.

3. Silicone Sealant

Silicone sealant (such as this) is the sort of thing you’d use around a shower tray. It can be used outside for the same purpose, but is obviously only suitable for small cracks and gaps.

You’ll also need a caulking gun. Use silicone sealant to address any cracks that might have appeared due to structural movement. Be aware that it needs replacing every few years though.

4. Flashing Membrane

Flashing membrane (such as this) is usually made from polyethylene and, unsurprisingly, covers the balcony flashing. This is the join between the balcony structure and the building – flashing is there to waterproof the gap.

You might find that the previous flashing has worn away or perished, which can happen over time. It’s not necessarily the hardest job, but make sure you know what you’re doing before you start.

5. Address Drainage Issues

This is obviously more of a preventative solution. Addressing balcony drainage should be part of your repair project, as ensuring there’s as little water as possible will reduce the chance of leaks.

While there’s only so much you can do, it’ll be worth monitoring your drainage during bad weather. If you notice a lot of standing water after heavy rain, consider contacting a professional to see how you can improve your drainage situation.

6. Waterproof Membrane

Waterproof membrane (such as this) is essentially floor underlayment. To use it on your balcony, you’ll need to put it over the existing floor and run it up the walls by a few inches. You’ll then need to put a new floor surface over the top.

This’ll stop water from soaking into the balcony floor, but could lead to drainage issues. Make sure you address point 5 as part of this solution to avoid this becoming a problem.

7. Contact a Professional

Due to the safety considerations of working on a balcony’s structure, it can definitely be worth calling in a professional. You’ll only really want to repair minor issues yourself, but anything that involves construction work should be left to a professional.

Be aware, though, that large construction projects will easily run into the thousands of dollars. But if you’ve got a leaking balcony, the long-term damage could be far more expensive.

Final Thoughts

Fixing a leaking balcony can be a straightforward job if you know the cause and it’s relatively minor. As with leaking plumbing, there’s a lot you can do with a bit of knowledge and some sealant!

However, if you’re concerned there might be more to the problem than you can see, don’t hesitate to call in a professional. In the long term, it’ll be a far more cost-effective solution.