This article deals with masonry balconies; concrete, tiles and grout, stone, etc.
There are two options, depending on your cause:
Balconies are a common source of water leaks in apartments and houses.¹ There are many reasons why a balcony can leak, and a few different options to repair them. In this article, Concrete Protection Company will identify the most common balcony leak causes, their solutions, and at the end of the article discuss how Shower Plug sealer can be used to waterproof a balcony.
To properly understand what causes a masonry balcony to leak, we will briefly look at the components of a balcony.
When the membrane is compromised, water will damage all the balcony’s components, but in different ways, and at different rates. The longer a leak is allowed to continue, the more damage can occur and cost to fix it. Even with a functioning membrane, the surface itself is at risk of water damage.
Shower Plug can repair and prevent this.
Masonry balconies leak due to a variety of possible causes. Below is a list of the most common ones.
First and foremost, masonry materials such as tiles, grout and concrete are not waterproof. They are inherently porous and will allow water to penetrate through to the membrane.
Unless the surface is made water-repellent with a sealer, water penetrates through and then damages all elements of the structure over time. This includes damage to the membrane.
Breaks in the surface like cracks in grout, tiles or concrete, are very conspicuous causes of balcony leaks. Water will pass through these cracks. The break can often be simple to patch up, using grout (see our article on how to repair grout). Once patched up, the entire surface should be sealed with Shower Plug for water-repellency. If the surface break is less than 1mm wide, this can be sealed using Shower Plug.
Broken/drummy/dislodged tiles would require the work of a tiler. Shower Plug sealer would still be important after the tiles are repaired, and tilers can apply the product as part of the repair.
Building expansion and contraction occurs when a building heats up and cools down. It also occurs when water saturates the building materials. As the building expands and contracts, it causes breaks in the structure. This occurs over the long term.
Some balconies/buildings will have expansion joints to compensate for thermal expansion.
Expansion and contraction causes breaks in the various components of the balcony, such as the surface, tiles and grout, concrete cladding, and the waterproofing membrane. In regards to leaking water, the most important breaks occur in the surface and the membrane.
The surface will break and crack in places such as the grout between tiles, between the wall and floor joints and tiles can even become dislodged or buckle, in small or large numbers. When this happens, water will leak through the broken surface and into the structure below.
The expansion and contraction process can also warp or tear the membrane.
Balconies often require expansion joints (flexible joints that allow for building movement) or it can buckle as the building moves over time.
Water also causes expansion and contraction of masonry substrates through a process called efflorescence.
In short, efflorescence is the white crystalline streaks that often form on exposed masonry surfaces. They are formed when water saturates a masonry surface and dissolves the salts and minerals contained in the masonry. As water then moves through the masonry it takes the salt and minerals with it. When the water evaporates, the salts and minerals are left behind as white crystals or streaks. This can form on the surface, but these crystals can also accumulate within the surface. When the minerals crystallise there, they expand, splitting the masonry apart, causing cracks. The cracks increase the ability of leaking water to pass through the masonry.
If you are seeing efflorescence on the surface of your masonry, this can indicate the cause of your balcony leak is the porous masonry itself. The masonry should be cleaned and then sealed with Shower Plug to prevent further efflorescence and leaks.
The waterproofing membrane is a waterproof sheet that lies underneath the surface, preventing water from soaking through the structure. They are commonly made from polymers, bitumen, rubber and/or other materials. Membranes commonly have a service life of 5-10 years after installation. Required by the building code in Australia, they are a necessary measure for waterproofing balconies.
Video depicting membrane failure:
The leading cause of membrane failures is errors made in workmanship.
Membranes are often complicated, labour-intensive and demanding pieces of technology. They require professionalism in knowledge, discipline and teamwork both within the application team and with other construction teams on-site, in order to be properly installed and coordinated. They can fail for many reasons associated with workmanship:
Generally, this is difficult to identify without training and equipment, but if the surface is porous and/or damaged, membrane failure is likely to be a reason why the balcony is leaking.
Membranes can be replaced by removing the tiles and replacing the membrane. The surface can be waterproofed by using a penetrating sealer instead, leaving the membrane redundant.
5. Pooling of water on balcony
Continual pooling up of water in the area, due to bad drainage or lack of sufficient fall, can lead to increased water pressure on the balcony and increase chances, or rates, of water leaks.
This is easy to identify and may require specialist help to fix.
6. Weather damage to balcony
Rain, heat, cold, UV-light, ocean-air salt and other forces all wear away at the integrity and certain parts of balconies.
7. Bad drainage on balcony
This will often lead to pooling as above.
8. No provisions for water overflows on balcony
In the event that there is a problem with drainage or heavy rainfall, there should be provisions for water to exit.
9. Inadequate flashing
Flashing is thin pieces of material installed to prevent the passage of water through vertical/horizontal joints, including the balcony floor and wall or the window/door opening.
This is a fairly noticeable problem; inspect the flashing for issues. It will need to be repaired professionally.
10. Inadequate expansion joints
If the balcony is buckling or breaking and there is no expansion joint, this could be a cause of your leak.
There are three options, from lowest to highest cost:
To prevent water leaking through the surface of the balcony, for most issues, we recommend applying Shower Plug masonry sealer.
Shower Plug is a liquid sealant that soaks into masonry surfaces and renders them water-repellent. It is a leading balcony sealing product, tested and appraised by Australian universities and the CSIRO.
Once treated with Shower Plug, the surface itself is the sealed barrier against water. No water can penetrate through. No membrane replacement is required. It is simple enough for DIY users to apply and is ready within 12 hours. Therefore, it is the most efficient way to fix a leaking balcony.
Shower Plug is applied in two coats, using a brush, roller or spray. It is then wiped off after the second coat, leaving no changes to the surface appearance or texture. The surface remains cosmetically identical to its original state, but it has become chemically waterproof.
Find out more about Shower Plug, here.
Membrane replacement is an option. A professional waterproofer, and/or builder or tiler will need to be contacted if that method is considered.
If the issue involves expansion joints, falls, drainage, flashing or other structural issues, a tradesman is required.
In both these cases, it is still useful to waterproof the balcony surface with Shower Plug once the main cause is fixed. This will ensure full balcony waterproofing is achieved.
With this information, you have a starting point to understand and fix your balcony leak.
If further information is required, Concrete Protection Company is available for consultation. Email [email protected].
To learn more about Shower Plug, see this page.
To purchase Shower Plug, see this page.