Tiled Balcony

How do you waterproof a tiled balcony?

We’re so lucky to have beautiful weather in Australia which means we spend a lot of time outdoors. A tiled balcony is a fantastic place to sit for meals, to read, have a beer or a glass of wine or to soak up the rays. Unfortunately, tiled balconies can be afflicted with leaks. Your first thought is probably “Oh no! That means we’re going to have to rip up the tiles to fix it!” Well, not necessarily. DIY balcony waterproofing without removing tiles is possible … but once you read this article, you may decide to call in the professionals.

Many residential and light commercial building owners seem to believe a tile installation is waterproof, and fail to pay enough attention (or money) to the proper treatment underneath.

The resulting leaks can occur undiscovered for years, eventually causing rot that requires major renovations. Not only does the structure need replacement work, but the tile application must also be removed to access it.

The water most likely entered through cracked grout joints or on the perimeters. If the deck is in a cold climate, the moisture freezes expand and cause tiles to erupt. Still, a failure in the tile installation does not mean a failure in the waterproofing system. If the membrane is intact and performing its function of keeping the water out, replacing a cracked (or erupted) tile or grout joint is relatively easy and inexpensive.

This article examines some of the common reasons for tile failure, the methods for building a deck to ensure it is ready for a floor finish, and the critical installation details for long-term durability and successful waterproofing.

Check out Hitch Property Constructions for a wide range of balcony repairs.

Symptoms of a leaky balcony

Leaking balcony repairs, either DIY or done by a contractor, are usually necessary when the balcony tile waterproofing hasn’t been done correctly in the first place. Or it could simply be a case of wear and tear in an ageing building. Have you noticed any of the following signs of water leaks on your tiled outdoor or rooftop area?

  • Cracked or missing grout
  • Splitting, cracked or peeling paint
  • Discoloured or stained tiles and grout
  • Loose tiles
  • A hollow sound when you walk over a tile
  • Growth of mould or mildew
  • Weakened or loose structural posts or railings
  • Water’ ponding’ in areas
Tiled Balcony

Causes for tile failures

From deck design to adhesives to maintenance, tiles can fail for various reasons.

Building the deck

When it comes to the slope, adding drains and scuppers increases the degree of difficulty. While it can still be accomplished with good design and careful framing, the most simple and effective way to deal with water is to let it flow over the side of the deck.

Assuming the joist spacing and sizing is appropriate for a tile assembly, the choice of materials and how they are fastened together plays a large part in keeping the grout lines from cracking or the tiles from popping off. The assembly needs to be very stiff and flat and built to substantially reduce structural deflection (i.e. the spring or give off the deck surface). A total thickness of at least 31.75 mm (1 ¼ in.) is required.

One option involves 19-mm (¾-in.) plywood with a 13-mm (½-in.) cement backer unit (CBU) fastened with thin-set bonding adhesive and appropriate screws. The joints of the overlay should not be over the top of the joists; they should be one-quarter of the distance to the next joist. The fasteners should only be long enough to attach it to the plywood beneath (and not to the joists), allowing it to ‘float.’

Flatness is important. If there are humps and bumps, the ensuing ponded water cannot be easily resolved by later floating it with filler. Any flatness issues need to be dealt with before the waterproofing membrane is applied.

Where to start with waterproofing balcony

If you are experiencing any of these conditions, you need to get help as soon as possible. Allowing a leak to spread will only worsen the problem and make it harder – and more expensive – to fix. A balcony tile leak repair is the place to start. There’s no point scrubbing the stains or re-grouting the tiles until the leak is found.

We use a specialised device to detect the leak. Our moisture detection scanning equipment locates the site so we can perform non-destructive repairs and then conduct remedial waterproofing services. This is done without removing tiles, which will no doubt come as a relief to you.

You’ll also be pleased to know that we don’t just leave it at that either. Your balcony waterproofing repair also involves restoring the area so that it looks as good as new. All the old, worn and damaged grout will be removed, and the whole surface will be given a thorough clean before re-grouting balcony floor tiles with a new layer of EPG epoxy grout. We use a high-quality polyurethane to finish all the internal joints for maximum sealing, to keep water out for good!

Finally, we apply two coats of clear waterproofing membrane and a clear penetrating sealer which will keep your tiles and grout stain resistant for up to 10 years, or we’ll return and treat the surface again at no charge.

Why is my Tiled Balcony Leaking and How Can I fix it?

When there is a problem, it normally is not due to one deficiency, but due to multiple compounding deficiencies.

You state that the peel and stick moisture barrier was properly installed. If it were properly installed, it would not be leaking. If it was installed properly, then something structural would have had to happen to cause a breach in the waterproof membrane to allow it to leak. Or perhaps after it was installed and before it was tiled over, something happens that caused damage to the membrane?

Bottom line is if there is a leak, then the membrane isn’t working for one reason or the other.

Cracks in the grout joint won’t cause a leak in the underlying membrane. Cementitious grout is porous, so water does go through it whether it has what sounds like shrinkage cracks, or stress cracks due to not having adequate movement joints installed.

Sealers over tiles do not make them waterproof. Even if the tile had been sealed, it would not have prevented the leak.

You should have movement joints in the installation to mitigate stress caused by the tile expanding when wet or when it heats up, and contracting when it cools and drys. A movement joint is a grout joint with a polyethylene closed-cell backer rod with an ASTM C920 sealant (100% silicone or urethane). There should be a movement joint at the perimeter of the installation at all transitions, and every 8′ to 12′ in all directions.

You should have drains on the balcony. Either a drain within the balcony or having it drain off the side of the balcony that has a drip edge flashing, so it doesn’t stain the side of the building. Not only should the surface of the tile be sloped to the respective drains at the rate of 1/4″ per foot, but the surface of the underlying peel and stick membrane should be sloped to a drain weep system at the rate of 1/4″ per foot. If there is not adequate drainage at the waterproofing surface, then in effect you are creating a reservoir of water that can’t escape.

The only way to properly fix it is to remove the tile assembly to find the problem and fix the problem. Otherwise, you are only treating the symptom and not the problem.

Some repair options that will not fix the problem does not meet industry standards, and may or may not solve the problem are:

1. You can remove the tile from the 3″ fibre reinforced concrete. If you do it carefully and if it is structurally sound, you can remove the tile so you can re-use the concrete base. You might have to patch some divots from the removal process. Prep the concrete and the apply a liquid applied waterproof membrane meeting ANSI A118.10 over the concrete and up the walls. Then install your tile over it.

2. Remove all grout from the tile installation and fill them all with backer rod and an ASTM C920 sealant. Make sure the perimeter joint is done too. Tool the joint to a concave shape, so it doesn’t get dirty from walking on it. Depending on how porous your Terra Cotta tile is, water may still be able to pass through it. In theory, if you use this type of sealant in all of the joints, it makes the joints watertight, it gives you movement joints in all joints to mitigate potential movement stresses, and it gives you some additional bonding strength between the tiles.

Looking for balcony repairs Melbourne? Look no further. Hitch Property Constructions has you covered.

Waterproofing Concrete Decks and Balconies


All surfaces to be waterproofed must be firm, clean, dry, sound and smooth. All grease, oil, wax, curing compounds, loose material, paint and any other contaminants must be removed, masonry surfaces must be pointed flush and surface defects repaired. New concrete must be cured for a minimum of 28 days.

External corners to be waterproofed must be bevelled to ensure a smooth transition of membrane from vertical to horizontal surfaces.


Installation shall be in accordance with AS4654.2-2012 Waterproofing membrane systems for exterior use – Above ground level – Design and installation, paying particular attention to Clause 2.6 Typical Termination Details. Tile installation shall be in accordance with AS 3958.1-2007 Ceramic tiles – Guide to the installation of ceramic tiles.

  • Install 12 mm fillet/bond breaker to internal corners using Admil SupaSeal PU. Admil SupaSeal PU is a Low Modulus, Hybrid Polyurethane, flexible joint sealant and adhesive that is free of Isocyanates and other hazardous raw materials and omits low odour.
  • Recess outside edge of the balcony to accommodate Seaton Tile Edge. Install Tile edge using Admil SupaSeal PU or Class 3 galvanised screws. Seaton Tile Edge is a high-grade Aluminium extrusion and is available in Clear Anodised or Powder Coated finishes.
  • Prime Seaton Tile Edge and all other non-porous substrates using WPA 160. WPA 160 is a specialised solvent-free primer designed for enhancing the adhesion of subsequent membranes, adhesives, toppings and decorative finishes over porous or non-porous substrates.
  • Apply WPA 460 Primer to the substrate to be waterproofed. WPA460 is a two-component water-based epoxy primer used to seal concrete and masonry surfaces.
  • Apply a minimum of two coats of WPA 500 or WPA 230 UV or WPA Rapid membrane to achieve the required dry film thickness. Ensure that the previous coat has completely dried before applying the subsequent coat(s). NOTE: All penetrations must be waterproofed. WPA 500 is waterborne, fibre reinforced, flexible waterproof membrane designed for use under tile finishes. WPA 230 UV is an elastomeric, one part, fibre reinforced, UV stable, water-based polyurethane membrane. WPA Rapid is a fast curing, waterborne flexible waterproof membrane designed for use under tile finishes.
  • Once the membrane is fully cured, install CTA Eco Screed with Efflock, ensuring a minimum 1: 100. CTA ECO SCREED is a pre-blended screed underlayment consisting of graded sand, cement and additives. EFFLOCK is a high performance, solvent-free, water-based liquid additive, ideal for the bulk impregnation of cementitious building materials.
  • Allow screed to cure, then apply WPA 460 Primer.
  • Apply two coats of WPA 500 membrane or WPA 230 UV, ensuring that the first coat has completely dried before applying the second coat.
  • Allow membrane to cure, then install Floor tiles using CTA Pro Premium or CTA Promaxset. PROHESIVE PRO PREMIUM is a premium quality, extremely high strength, polymer-modified, cement-based adhesive. PROHESIVE PRO MAXSET is a high strength, polymer-modified, flexible cement-based adhesive, which has been specially developed for installing most types of tiles.
  • Grout tiles using the appropriate colour of Polyblend Grout. POLYBLEND grout is a premium high-quality polymer modified, flexible, cement-based, coloured grout designed for grouting most types of tiles including ceramic, porcelain, natural stone and glass mosaics.
  • Install backing rod to all perimeter and intermediate movement joints and seal with silicone or polyurethane sealant.

What’s Best for Waterproofing your Balcony

Turning your outdoor living space into a gorgeous area and upgrading your balcony is an imperative part of interior designing. Whether you enjoy a cup of coffee on a rainy day on your balcony or relaxing with a good read in hand on your patio, outdoor living spaces have evolved. There are plenty of options to choose from while selecting the perfect flooring for your balcony. From concrete pavers to tiling to wooden decks, there are many flooring options you should look into along with their pros and cons. Let’s look into three of the popular choices that most people use for their balcony upgrades and what’s best for weatherproofing them.


Concrete flooring for your balconies might not sound as enticing as the fancy tiles you could choose from. Well then, we’d say you haven’t explored the option well enough. Concrete floors have been upgraded from the standard shades of grey to having colours and patterns. Durability is one of the key factors why concrete remains one of the top choices for most condo owners. They are tough, resilient and easy to maintain. While there are many advantages to concrete flooring for balconies, the disadvantages are penetration of moisture through the concretes if not sealed well, it can also get slippery and cold during winters. Waterproofing concrete balconies can be dealt with great care with the help of experts with the use of products like Westcoat’s SC-10 Acrylic Topcoat.


Ceramic or porcelain tiles are a great option for outdoor spaces too. They’ll give your balcony a stylish look with the wide variety of colours and styles you have to choose from. With the help of hard protective top layer on these tiles, they become water-resistant and make them highly durable too. Tiling has many other advantages too. They are stain-resistant and are easy to maintain. A waterproofing membrane can be installed to ensure weatherproofing is done well. When the tiled balcony is not waterproofed, it can lead to several problems too. From water damage to paint peeling off, the fixes will get expensive. Hence, it is important to have waterproofing done before the tiling is installed.

Hitch Property Constructions has a wide range of the Melbourne balcony repairs right here. 

Interlocking Deck Tiles

They are easy to install and easy to replace too. There are a variety of options available for deck tiles as well as a choice of finishes for these tiles, including real wood fibres and man-made plastic material. However stylish they may look; deck tiles aren’t a permanent flooring solution as they aren’t directly attached to the surface below. Waterproofing deck tiles can be done by installing rubber, vinyl, and aluminium below the decking.

While choosing the flooring solutions, always keep safety your top priority, followed by weatherproofing the flooring. Whiles tiles and concrete can prove to be the best solution. In the long run, interlocking deck tiles are an amazing choice for those who are looking at style as a key factor. From installing a waterproofing membrane around the perimeter of a tiled area to effectively provide a waterproof barrier to applying a penetrating sealer to block water penetration, there are several options to weatherproof and waterproof your balcony. No matter what option you decide to go ahead with, always consult a flooring expert near you to help you make the right decision.

Scroll to Top