Waterproofing For Roofs

What is the best waterproofing for roofs?

Waterproofing a roof is not something that many homeowners tend to worry about. Surely your roof is already sufficiently waterproof as is? It might start that way, but over the years, your roof might not be able to keep out even the tiniest of leaks. Roofs should have quality roofing maintenance done to them on a regular basis from the time they are installed to avoid issues further down the line.

Waterproofing is something you must always pay attention to, especially if you live in an area which experiences high amounts of humidity and rainfall, as well as strong winds and storms. Roofs need regular inspections and maintenance work throughout the year to prevent or fix any problems, such as a leaking roof, before it gets worse. We advise you to get your roof inspected twice a year and especially after any severe storms.

Imagine a rainy day when you notice a dripping sound hitting the inside of your plaster ceiling. Over time, the walls and ceiling start to turn brown, and the paint starts to bubble. That’s what happens when your home waterproofing has broken down.

Waterproofing prevents water from seeping into the surfaces of your home and causing major problems like mould growth and damage to your property.

At Hitch Property Constructions, we offer the best range waterproofing services to rectify your water issues. 

Take measures to prevent concrete cancer.

Concrete cancer can be devastating, but what causes it? The term itself is a bit of a catch-all for a variety of problems associated with concrete embedded with steel.

During construction, concrete is reinforced with steel bars or, in some cases, mesh. As a metal, steel can rust after exposure to the elements, like water or air. Steel that is corroding is forced to expand. This expansion causes the surrounding concrete to crack and even break. Cracking exposes even more of the steel, which leads to increased oxidation and further damage to the concrete.

The belief that steel rods won’t come in contact with water because they’re surrounded by concrete is wrong. It’s important to understand that concrete is porous, and can absorb water. Also, a failure to adequately waterproof can increase the likelihood of concrete cancer. That’s why it’s essential to take the proper precautions to prevent concrete cancer. In situations that demand remediation, there are also things you can do.

Waterproofing For Roofs

The phases of concrete cancer

According to the Australian Concrete Repair Association (ACRA), there are four stages of concrete cancer progression. In general terms, the cost to fix concrete cancers multiples by roughly five through each stage of cancer’s progression in the concrete. This is sometimes referred to as the ‘Law of Fives’.

  • Design, construction and curing of concrete
  • Corrosion has initiated, but damage propagation hasn’t started.
  • Deterioration begins to propagate through the concrete.
  • Advanced propagation concrete cancer and significant damage.

By the fourth stage, a complete knockdown of the structure might be the only solution. So remember to act early and if you think your premises has concrete cancer.

Concrete cancer assessment

In circumstances where concrete cancer is potentially affecting your structure, it’s best to call a professional. The first step in preventing or repairing concrete cancer is to have the structure analysed by a specialist. From here, recommendations can be made for remediation of the structure and ongoing prevention. In most cases, if you act early enough, the structure won’t need to be knocked down.

What to do before waterproofing a roof

A large proportion of the flat roofs covered two or three decades ago with single-ply roofing membranes such as torched-down modified bituminous membranes (mod bit) or with EPDM are today good candidates for being recovered. Entirely replacing the old roof system with a new one is often prohibitively expensive. Still, in the past several years, liquid applied roof systems emerged on the market as reliable, worthy alternatives.

The first condition that must be met in choosing the right material is the compatibility between the existing roof surface and the liquid product intended to be used. Not paying attention to the type of material previously used to coat single-ply roofs can be a costly mistake. For example, it is a bad idea to apply urethane over a surface previously coated with acrylic elastomeric. The solvent contained by most urethane coating presents a high risk of re-emulsification for the acrylic. Another example is a roof previously covered with silicone. This type of surface does not accept any other kind of coating, as silicone surface will obstruct the adhesion.

Equally important before waterproofing a flat roof is the proper cleaning of the substrate.

Choosing the proper sealer for your concrete

All exposed concrete should be protected with a sealer. A failure to use the right sealer, or to properly apply the sealer, increases the risk of concrete cancer to your structure, leading to expensive maintenance, repairs and replacements down the track. Sealers protect from moisture and prevent the build-up of mould and fungus on the concrete.

How long should a sealer last?

A good concrete sealer will last around five years before a reapplication is required. Resealing should be completed as regularly scheduled maintenance works and prioritised to prevent damage.

How does concrete sealer work?

When waterproofing concrete, a topical sealer is applied to the surface of the concrete. The sealer is impermeable (provided it is applied correctly) and forms a waterproof membrane around the concrete, preventing moisture from entering the concrete. Topical sealers can be made from acrylic, epoxy and polyurethane-based materials. Many are decorative in colour and style.

Are there permanent sealers?

Permanent sealers do exist, though they leave a matte finish and are not available in decorative colours. Permanent sealers work by filling all the tiny holes in the concrete. They are made from silicate, silanes or silicone and are also referred to as penetrating concrete sealers.

Here are the five most common methods of waterproofing your roof and floor:

Cementitious waterproofing

This technique uses cement to create a solid, water-resistant layer. The cement is mixed with an acrylic additive to create a sturdier, durable base, then applied as a thick layer and left to dry and harden.

It doesn’t expand or contract under heat exposure. This technique is usually applied in household internals, waterproofing your bathroom before the tiles are laid.

Elastomeric waterproofing coating

In elastomeric waterproofing, a special rubbery liquid is used. After applying a coat or two, it cures into a thin rubber waterproof membrane.

Unlike cement, this layer is stretchable. This is important when used as outdoor waterproofing, as it can elongate up to 280% in harsh sunlight.

The liquid can be rolled, troweled or sprayed on. This method is most suitable for roof waterproofing.

Bituminous waterproofing coating

Bitumen is used to pave roads, but, it is also used for waterproofing. Also known as asphalt, it’s flexible due to the polymer grade and fibre reinforcements.

This black liquid is usually applied like paint, spread onto the surface. Due to it containing bitumen-based substances, it isn’t suitable for sunlight exposure as it turns brittle under heat.

So, if used on a rooftop, it needs to be covered by another protective layer such as cement.

Looking for the best waterproofing company? Look no further! Hitch Property Constructions has you covered. 

Bituminous waterproofing membrane

This form of waterproofing comes in a sheet and is rolled out onto the surface. It’s most suitable for low-sloped roofing due to its effectiveness.

Membrane waterproofing comes in two types; torch-on and self-adhesive.

Torch-on membranes are applied with a blow torch and burned as they are being rolled out, whereas self-adhesive ones stick onto the surface.

However, self-adhesive ones tend to have a shorter lifespan as they wear out over time.

Polyurethane liquid membrane

The last method is also the most expensive and is used mainly on flat roofs. It’s the simplest form of liquid waterproofing and can withstand the exposure of elements, thus deeming it both an exposed and non-exposed system.

It is also highly malleable meaning it can stretch without giving way. However, polyurethane is sensitive to moisture content. The surface of the structure must be thoroughly evaluated before applying to ensure it doesn’t cause damage in the long run.

Overall, it provides a sleek finish and is rather durable by regular standards.

Roof Designs For Waterproofing

The style and installation of your roof are important for a durable roof and peace of mind. Some roof designs might be more susceptible to leakages. Sloped roofs promote satisfactory drainage as the water can run off the roof, rather than flatter roofs which might allow for water to pool.

Your roof should also allow for water to run off further from your home’s foundations as water seeping in can make them weaker. Correctly-installed and functioning gutters and proper drainage are essential. These factors will increase the lifespan of your roof and keep leaks at bay. Flashing is another important component of a waterproof roof. This is the metal that covers joints or projections in roofs to stop water seeping through the roof.

Water-Repellent Layers

To the average homeowner, a roof might look like a rather simple structure. But your roof is a complex system made up of various layers. These include a waterproofing method which creates a barrier underneath your roof tiles or shingles. It protects your home and its valuable possessions from harmful leaks.

A roofing membrane can be installed on the roof frame and act as extra protection against moisture beneath your roofing material (tiles or shingles are recommended options for effective waterproofing material).

If everything has been installed properly, the roof will keep your home dry and safe throughout the year.

Waterproof Roof Coating (GACO)

Waterproof roof coating (what we call GACO) is used on flat decks and not sloped roofs. This is a good option if your roof has no underlying damage. If it has issues such as holes or cracked flashing, you will first need to get those repaired before you use a surface-level method such as paint. This way of waterproofing is convenient and easy and aesthetically enhances your roof. But you get what you pay for, and waterproofing paint should never be used as a temporary solution to a permanent problem. Rather, use it as an additional waterproofing system. Most good quality waterproofing paints also offer UV protection and a built-in membrane, both of which increase the longevity of your roof.

Get a licensed roofer to apply the waterproof roof paint before the rainy season and after any necessary repairs have been made on your roof. Applying the coating is a multifaceted process that involves various stages, each of which needs to be carried out carefully and skillfully.

Waterproofing your roof is something to seriously consider, especially given the amount of rainfall we experience in South Florida. A leaky roof can cause permanent damage to your home and your valuable possessions. Waterproofing boosts your roof’s lifespan and overall value, especially when completed by licensed roofers. A licensed roofing contractor will inspect your roof and figure out the most effective waterproofing methods for your situation.

Steps to waterproof a roof

A typical application of liquid-applied roof membranes consists of five main steps, which should all be treated with the utmost importance, following the product manufacturer instructions. These steps are cleaning, priming, treatment of details, main coating application, and inspection.

  • The first step in waterproofing a roof is cleaning of the substrate. All successful liquid applied membrane applications require superior adhesion. Because of this reason, proper cleaning is just as important as the actual correct application of the liquid material. Typically, pressure washing is the most common method for cleaning the substrate surface. This process eliminates the so-called bond breakers. Additionally, this will expose details needing treatment, that may not be visible at first glance.
  • Following cleaning, priming of the surface is designed to improve the adhesion of the membrane. Primers also aid to block bleeding of the bituminous oils from the existing roof through the liquid membrane. Before the application of most primers, the contractors must ensure the surface is dry. To reduce drying time contractors generally use air blower or torches.
  • The third step is the treatment of details. Contractors must carefully treat all details, and only after this step is completed, should they resume the field application of the liquid membrane. Details such as interior and exterior corners, as well as wall to floor type corners, metal flashing terminations and penetrations such as pipes, vents, drains, etc., are typically pre-treated with reinforcing fabric embedded into the liquid membrane and with a flashing grade sealant.
  • Next step is the application of the liquid membrane onto the roof. There are two kinds of applications of liquid applied membranes; some require the impregnation of reinforcing mat during installation, and some do not. Regardless of the fabric mat is mandatory or not, most of the manufactures require the coating application to be performed in two or more successive layers. The consumption rate of each coating product is stated in the manufacturers’ technical specifications. Method of application, substrate porosity, temperature, and waste are external factors that may influence the specified consumption rate.

In most projects, inspection is required by the manufacturer during all phases of the application. This may include, coverage of the primer, pull-out mock-up test, visual inspection of the detail treatments, and nonetheless inspecting the millage of the applied coating. Respecting the wet film thickness during application is important. Too much liquid product applied at once will result in uncured material underneath the skinned surface of the membrane. Not enough material to meet the required millage most likely will lead to premature failure of the membrane. Fish-mouths at the edge of the fabric signalise improper coverage of the reinforcement mat at the overlapping section. All such errors must be noted and corrected at the time of the inspection.

Concrete flat roof construction and issues

It is now more common to see home designs which incorporate a flat roof to make it look both appealing and elegant in style. However, the proper design of such a roof style is required in order to ensure rainwater is drained away from the roof as soon as possible. ‘Water-ponding’, or the stagnation of water due to rainfall on such roofs, is the leading cause of deterioration of concrete materials in roofing.

Variations in both temperature and moisture levels can lead to differential thermal movement. Combined with the potential acids left by rain that has evaporated, this can lead to the serious deterioration of what should be a stable, concrete roof.

Protecting your rooftop

Concert rooftops are exposed to the elements 24/7, so they must be properly designed and waterproofed to prevent leaks through the roof. Rooftop leaking can cause ongoing issues in the home. Beyond water damage to the interior, it can also affect electrical components, lighting and insulation. Ideally, you want preventative measures in place from the get-go, but if you think your concrete rooftop could be leaking or letting moisture in, it’s better to take action sooner rather than later.

Roof membrane systems

When looking at ways to waterproof a concrete roof, a waterproofing membrane is considered to be the most important aspect of a roofing system, as it is the key to keeping water out of the building. There are varying types of roof membrane systems on the market, so it’s important to understand the differences in order to choose the right system for you and your construction needs.

Pre-formed sheet membranes

Pre-formed sheet membranes are an excellent choice for waterproofing your roof, and there are two versions available in the market. These membranes are supplied as a waterproof sheet and require them to be welded/joined together to form a watertight membrane.

You may find Polyvinyl Chloride (PVC) pre-formed sheet membranes on the market. They are well designed to deal with the pressures of high winds, excessive rainfall and other weather-related stresses including being UV Stable. Some products are also modified to be fire retardant, so they can also provide a good fire rating to help protect your building in case of an emergency.

Wolfin Waterproofing Systems

One such polymeric PVC waterproofing system is the Wolfin sheet membrane system. Wolfin can be laid loosely on the surface or bonded (Wolfin GWSK) and due to its high-quality composition, has outstanding properties to enable greater longevity & service against all climates and conditions and are used in new & remedial applications. Wolfin is used on most substrates and areas and is compatible for a number of installations including over bitumen, asphalt, sheet and liquid membranes and is used in critical areas (Over Habitable Spaces) where waterproofing is of the highest importance. This German-manufactured product also has a high tear and puncture resistance, making it one of the most trusted and reliable products on the market to date.

We have a huge range of waterproofing services Melbourne at Hitch Property Constructions that offers stress-free services for any water problem you got! 

Cosmofin Waterproofing Systems

Cosmofin is known in the industry as being a reliable and long-term product that provides great performance in a number of applications. This product is a PVC waterproof membrane that includes a central glass non-woven inlay. Cosmofin is often used for a wide variety of building structures such as residential, commercial, civil and marine construction projects. It is also used for many applications, not exclusive to rooftops, such as balconies, terraces, retaining walls and planter boxes. With its clean application and any waste being recyclable, Cosmofin waterproofing systems are also extremely high tear and puncture-resistant.

Both Cosmofin and Wolfin products are versatile enough to be used on a number of materials. Not limited to concrete roofs, these products can be utilised to waterproof other building materials including steel, timber, CFC, masonry etc.

Designed to withstand chemicals in domestic and industrial constructions, they’re highly durable, UV stable and in the event, it is required, easy to repair.

Whether it’s a concrete rooftop that you’re concerned about, or perhaps there are other construction materials you want to ensure are stable and waterproof for years to come, there’s no doubt that investing in superior waterproofing systems is the best way to protect your assets. Not only can you protect your roof from the extreme climates Australia endures, but you can also have the peace of mind that you are doing the best that you can to protect your building and constructions from unnecessary damage.

And remember, if you’re having any other water problems in the home it’s best to consult with a plumber before taking action.

Scroll to Top