Do balconies need to be waterproofed?

Building waterproofing methods are the formation of impervious barriers over the surfaces of foundations, roofing, balcony decks, and walls. This includes other structural members of the building to avoid water penetrations through such surfaces.

Materials commonly used for building waterproofing include cementitious material, bituminous material, liquid waterproofing membrane, and polyurethane liquid membrane, among others.

Waterproofing in buildings is needed for the basement of bathrooms and kitchen, balconies, decks, green roofs, structure, terrace or roofs, walls, water tanks, swimming pools, and the like.

Completing the terrace and the balcony waterproofing of the buildings which will be exposed to water is important for the aesthetic properties and performance of a building.

You might have experienced problems related to a leaking balcony or a terrace after heavy rain. The downpour forms a pool in your balcony, and it starts to leak down to the lower floor. The leaking from balconies is a serious problem. It can cause cracks and chips, not to mention the unsafe joints and sealants.

Just ceramic coating applied to the terraces and balconies of the building does not provide any protection without completing the waterproofing. There will be water leakage from the terraces to be constructed in this way, which will cause the lower floor comfort problem and reduce the life of the building.

Therefore, the selection and application of the right waterproofing material play an important role in terrace and balcony isolation. In this article, we will go through balcony waterproofing and the question of how to do you waterproof an outdoor balcony.

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Why Must Deck and Balcony Membranes be Maintained?

Without proper maintenance, water may get in through holes and cracks in the membrane and joints that have separated and produce leaks to the interior, damage to the wall assembly and rotting of the deck or balcony structure. Holes caused by sharp heels, table and chair legs, and damage produced by placement of heavy objects and careless use of tools may also increase the risk of water entry. Moreover, hot barbeques, spilled gasoline or solvents can melt vinyl membranes. Shrinkage of the building frame can also cause the balcony slope to change, and ponding (standing water) at the wall to occur.

All these possible situations create a need for more diligent inspection within the first eighteen months of service.


What do you need to know about balcony waterproofing?

Do you have a balcony that requires a waterproof membrane? This is a vital step in sealing a balcony to ensure. It does not allow any water to penetrate your house and cause costly water damage.

In this article, we will tell you the main steps to take to ensure your balcony is waterproofed correctly. Please note, that SCR does not recommend this as a DIY project – but recommends you engage a Certified Water-proofer, to ensure your balcony receives a Waterproofing Certificate.

The following guidelines are from the Australian Standards for Waterproofing membranes for external above-ground use AS 4654.2-12

How to Apply A Terrace And A Balcony Waterproofing

Waterproofing applications, which have great importance for the protection of open spaces such as balcony and terrace, can be carried out in a few steps. Accordingly, it is necessary to prepare the application surface for the system that will provide waterproofing under ceramic coatings. How do you waterproof and outdoor balcony or terrace? You can take a look at the following preparation and application steps in detail.

The Preparation Step

It is necessary to prepare the application surface before applying the ceramic coating. Anti-sticking residues, loose parts should be cleaned before applying waterproofing materials. The surface should be smooth, firm, and clean. If required, surface defects should be repaired with suitable repair mortars.

Repair and reinforcement systems, specially developed by building chemicals expert BAUMERK to repair surface defects, will offer the most suitable solution for your needs in this sense.

The Chamfering Step

Cement-based waterproofing To prevent the water from accumulating in the corners of the terrace and balcony to reach the lower layers, waterproofing should be provided by applying chamfer bands to the wall and floor junction points. Chamfer tapes, also known as waterproofing tapes, must be flexible to protect against possible expansions and maintain their elasticity.

Besides, high resistance to tearing is significant for terrace and balcony waterproofing efficiency. Baumerk’s complementary product options may provide the best answer to your needs.

Application of The Waterproofing Layer

After the surface preparation, the waterproofing layer application is started. At this point, it is critical to choose the most suitable waterproofing material in accordance with the water exposure of the building, its contact with the sun rays, and other needs. The terrace, balcony & wet-damp floor waterproofing products developed by Baumerk for different demands can be considered as an ideal option for terrace and balcony waterproofing layer applications.

Application of The Last Layer Protection Material

After applying ceramic coating on the terrace and balcony surfaces, proper joint filling application and last layer protection material should be used. In the case of no coating, it will be important to choose a topcoat paint that is UV light resistant, non-fading, and resistant to pedestrian traffic.

Waterproofing Over Existing Tiles

How do you waterproof over existing tiles? It is recommended to remove the existing tiles and then waterproof a balcony if the existing waterproofing system is failing or tiles are in bad condition or if the problem is related to tiles.

However, waterproofing over existing tiles is also possible. In this case, it is important to check if the existing tiles are in good condition. They should be firmly attached to the substrate for a better result.

The correct waterproofing application is essential for the comfort of your building, and therefore, for your comfort. Waterproofing is one of the factors that directly affect the aesthetic appearance of the building, and incorrectly applied terrace and balcony waterproofing can also lead to irreversible damage.

Waterproofing Methods And Types For Balcony Decks

Cementitious Waterproofing

This process is among the easiest waterproofing methods in any construction. Cementitious waterproofing requires materials that are easily available from suppliers of masonry products, which are easy to apply or mix.

The common applications for cementitious waterproofing include the following:

  • Bridges
  • Dams
  • Marine cargo ports and docks
  • Parking structures and lots
  • Railway and subway systems
  • River locks/channel and concrete dikes
  • Sewage treatment plants
  • Tunnels
  • Water treatment plants

Liquid Waterproofing Membrane

There is a thin coating that consists of a primer coat and a couple of coats on top applied by roller, spray, or trowel. Liquid membrane waterproofing methods can offer more flexibility compared with the cementitious type of waterproofing. The liquid will cure the surface into a rubbery coating on the wall.

The elongation properties of the coating can reach as high as 280%. But the durability of the coating will depend on the type of polymer that the manufacturer will use for making the liquid waterproofing.

Liquid waterproofing membrane can be composed of polymer-modified asphalt, which can be applied by spray. Polyurethane liquid membranes are also available for different manufacturers in separate grades for roller, spray, and trowel.

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Bituminous Coating Waterproofing

It is a type of coating that can be used for waterproofing buildings and provides a flexible protective coating. The bituminous coating uses formulation and polymerisation grade to provide protection and flexibility against water due to the polymer grade and the reinforcement of fibre.

Bituminous coating is otherwise called asphalt coating in which the most common applications include areas that are under screed wet. Such would be an excellent protective coating and waterproofing agent, particularly on surfaces like concrete foundations.

Bituminous Membrane Waterproofing

Membrane waterproofing is a famous process used for low-sloped roofs or balcony decks because of its proven performance. The self-adhesive membrane and torchon membrane are used in the bituminous waterproofing membrane.

Self-adhesive compounds contain asphalt, fillers, and polymers. In addition to that, some compounds like oils and resins are also added to improve adhesion characteristics. Torchon membrane is also another type that can either be exposed or covered. The exposed membrane has a granular mineral aggregate to withstand wear and tear.

Polyurethane Liquid Membrane Waterproofing

This process is used for the flat roof area, balcony decks, and areas that are exposed to weathering. However, this type of waterproofing is said to be expensive. That said, it can offer higher flexibility. Nevertheless, polyurethane is very sensitive to moisture content, so it is essential to evaluate the moisture content in the concrete slab. Otherwise, debonding or peeling of membranes can happen after some time.

Tiled Balcony Waterproofing

Balconies that are tiled with ceramic or homogeneous tiles look attractive and are easy to maintain. However, they are susceptible to cracks easily, leading to water seepage issues which can potentially cause considerable damage. Apart from tiles, wooden decking and concrete base are also common balcony finishes in Singapore. For such cases, it requires a specialised type of coating to effectively waterproof the entire surface by creating a preventive coat that avoids the need to water leakage repair.

Tiled balconies are also prone to water damage and water formation. If it has been assessed that the concrete base is of sound structure, in some cases, it may be possible to resolve water seepage by applying waterproofing over the tiled surface with water-resistant coatings. However, the grout has deteriorated; such practice is generally not recommended. What is then required would be hacking of the existing tiles to install a new waterproofing system altogether. When properly maintained periodically, the tiles on your balcony will benefit from treatment with water repellant applications that help maintain a preventive coating against future water intrusion.

Concrete Balcony Waterproofing

For balconies with a concrete finish, the waterproofing membrane is likely to invariable eroded over time without adequate protection. However, it is not a cause for worry as we can employ various preventive systems to protect concrete balconies from the elements. Such systems can be applied over the existing concrete surface, to avoid the inconvenience and additional cost from hacking works as well as disposal of debris. One such application is using fibre liquid as well as a water-based resin to treat concrete surfaces.

Exterior Balcony Waterproofing

Exterior balconies require well-designed drainage and water run-off to prevent water stagnation and pooling, which will create cracks due to penetrative action over time. It is important for drainage to be well incorporated into the downpipes to reduce the risk of damage by safely dispelling water out of the balcony.

Signs Your Balcony Needs Waterproofing Attention

In Singapore’s climate, the balcony could be the most vulnerable part of a building, as it is exposed to the ravages of the weather. High rainfall and water run-off from balconies lucid lead to extensive damage to interiors and other structural problems that could be costly to repair.

Most commonly, balcony leakages are experienced in office or homes, leading to the formation of stains and moulds. Tiny cracks in the balcony waterproof system could also cause leaks, even if they’re so tiny that they are not visible. Water stains and mould observed are indications that water has accumulated over time somewhere. Having observed signs that there could be a leakage, the next logical step is to identify the source of the leakage. One should then check the areas around the balcony and surroundings for any signs of water and mould. Should they fold directly blow the bathroom, water leakage repairs might be necessary, while waterproofing repairs might be required if the area above the leakage is exposed to water frequently.

As balconies are heavily exposed to the elements, the waterproof system and concrete are vulnerable to water damage over time. Other signs of a waterproofing collapse are:

Evidence of Efflorescence

Efflorescence appears and becomes visible when salt accumulates with the presence of water, a clear sign that water draining is not functioning properly.

The appearance of Stains or Mould

Stains or moulds that start to appear in both the interior and exterior parts of your balcony could be signs that the waterproof system is failing.

Cracks In Walls or Flooring

Balconies can be easily exposed to impact and external elements due to weather conditions. Cracks might therefore appear in a leaking balcony both on the walls and ceilings in the balcony area.

Paint Wearing Off

Peeling paints could be signs of moisture, a clear warning that your balcony should be thoroughly inspected and possibly have a new waterproofing system installed if necessary.

A Few Common Reasons Why Balconies Leak

Insurance statistics have shown the highest number of waterproofing failures are balconies, terraces, rooftops in high rise dwellings and commercial buildings. The design criteria in many of these buildings lack appreciation for water control.

  • Water ingress into dwelling spaces below causes disputes between neighbours and often ends in litigation.
  • The widespread problem of mould spoors from damp affected areas, which are detrimental to people’s health.
  • Water ingress is affecting concrete structures with an eventual demise of the critical structural components.

And it is not always the waterproof membrane at fault.

Other Deck and Balcony Maintenance Items

Guardrails and Guardwalls

Guardrails and guard walls are important safety features designed to prevent falls from balconies and decks. Attention needs to be paid to locations where the guardrail connects to the wall. All guardrail connections, either through the membrane or to the wall, should be regularly inspected and maintained to reduce the likelihood of water penetration into the wall assembly or building structure.

Depending on the type of construction, guard walls are particularly susceptible to leaks at corners and intersections with the exterior wall (saddles). Regular inspection and maintenance attention is required, including any sealants that may be used at these locations.

Drains and Gutters

Drains and gutters are important parts of a deck or balcony system that require maintenance. A critical yet easy maintenance item is to keep drains and gutters working properly by regularly cleaning balcony and deck floor surfaces to remove any dirt or debris, e.g. leaves and twigs. This will ensure that drains and gutters are free-flowing and do not clog.

Keeping deck and balcony surface clear of dirt and debris is also important for continuous “edge wrap” drainage systems. Located at the perimeter of the deck or balcony, these systems drain the water into a continuous gutter. It is important that these systems remain free-draining to avoid clogs and water over-flow situations.

What Maintenance Must be Performed on Decks and Balconies?

When cleaning the membrane, use common household cleaners containing plastics friendly ingredients. Never use solvents, alcohol, paint thinner or lacquer thinner to clean the membrane because these products may degrade vinyl and urethane membranes.

If you have any doubts as to the proper approach to specific maintenance requirements, you should obtain professional advice from a building envelope consultant.

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How Often Must Decks and Balconies be Inspected and Maintained?

Deck and balcony membranes should be inspected at least every two years for both new and existing buildings.

If you live in a new building, the condition of decks, balconies, railings and other related components should be inspected before the end of year one and year two to detect any possible problems stemming from wood shrinkage or structural movement of the building.

The condition and strength of the guardrails and guard walls should be inspected every two years. Balcony and deck surfaces, including drains and gutters, should be cleaned at least twice a year (or as needed) to remove leaves and other debris and to prevent clogging and potential water build-up problems.

Decks and Balconies provide residents with great enjoyment and direct access to fresh air and the outdoors. Like all other building components, they require routine maintenance, inspection and repair by qualified contractors and consultants to ensure durable performance.

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