What is Liquid Waterproofing Membrane and How is it Applied?

Waterproofing is a fundamental aspect of the building process, crucial for protecting structures from water damage. Without proper waterproofing, water can seep into homes and buildings through various points such as roofs, balconies and bathrooms, leading to costly damage. In this article, we’ll explore one of the most versatile solutions on the market today: liquid waterproofing membranes.

What Is a Liquid Waterproofing Membrane?

A liquid waterproofing membrane is a protective barrier designed to prevent water from entering structures. Once applied, it cures to form a continuous membrane that adheres to a range of substrates, including concrete and metal.

These membranes are commonly made from materials such as polyurethane, acrylic and bitumen-based compounds, which offer different levels of flexibility, durability, and UV resistance.

Benefits of Liquid Waterproofing Membranes

One of the key advantages of liquid waterproofing compared to sheet or torch-on alternatives is its ability to cover irregular shapes, corners, and details without seams. From your balcony to your basement, it can cover most of your home and is suitable for tricky corners where sheet membranes can struggle. Many products also offer strong UV and weather resistance, making them a smart choice for beach homes.

Liquid waterproofing is also flexible and durable. This is important because buildings move over time, so the liquid waterproofing membrane can move with them without cracking, making it particularly effective in environments subject to thermal expansion or structural vibrations.

What Is the Lifespan of Liquid Applied Membrane?

Liquid membranes offer excellent longevity. You can expect a lifespan of at least 10 years with proper surface preparation and correct application. Some high-quality liquid waterproofing membranes may last even longer, especially if maintained regularly.

The Common Applications of Liquid Waterproofing

From pools and bathrooms to balconies and rooftops, liquid waterproofing is among the most versatile waterproofing solutions available. Its ability to form a seamless, flexible membrane makes it suitable for a wide range of environments.

One of its key advantages is its compatibility with a wide range of substrates, including:

• Concrete
• Wood
• Tiles
• Bricks
• Metal and aluminium
• Plywood
• Natural stone
• Fibre cement sheeting
• Villaboard
• MDF
• Interior and exterior cladding
• Stone
• Render

Types of Liquid Waterproofing Membrane Materials

Liquid membranes aren’t a one-size-fits-all solution. There are different types used for specific surfaces and projects. As such, it’s important to choose the right liquid waterproofing membrane. The four most common types of liquid waterproofing membranes are:

1. Polyurethane-based membranes
2. Acrylic-based membranes
3. Bituminous liquid membranes
4. Liquid rubber

Polyurethane-Based Membranes

Polyurethane-based membranes are known for their exceptional UV resistance and can withstand temperature changes and movement without cracking. This property makes them a great choice for areas exposed to the sun, such as roofs and balconies.

Acrylic-Based Membranes

Acrylic membranes are water-based, environmentally friendly and breathable. Their ease of application and low environmental impact make them the ideal choice for sustainable projects.

Bituminous Liquid Membranes

These bitumen-based membranes are excellent for below-grade applications like foundations, basements, and retaining walls because they bond well to concrete and masonry and create a tough, waterproof barrier.

Liquid Rubber

Liquid rubber membranes offer high elasticity, durability, and fast curing times. They also offer excellent adhesion and the ability to withstand harsh weather. Thanks to their versatility, they’re used from roofs and gutters to foundations and planters.

Professional Waterproofing Application vs DIY

While DIY application of liquid waterproofing is possible, certain factors can influence whether it’s a feasible choice. For smaller, less complex jobs, DIY may be suitable, but it still requires an advanced level of knowledge and attention to detail. For larger jobs or if you have concerns about surface preparations, it’s advised to enlist the skills of a professional. Incorrect application can lead to incomplete coverage, weak adhesion and ultimately, water ingress.

Tools and skills required for DIY

For smaller jobs like balconies, bathrooms, or planter boxes, DIY may be suitable. Essential tools include brushes, rollers, a primer, and a steady hand. You should also research surface prep, application thickness, and drying times before commencing.

When to hire a professional

For large-scale jobs, high-traffic areas, or projects involving fixing leaking roofs, basements, or commercial buildings, it’s best left to a qualified waterproofing contractor. Creating watertight spaces is essential for the foundations and structure of your home, and professionals have the experience, equipment, and product knowledge to do the job properly.

Common mistakes to avoid

One of the most common mistakes is people skipping proper surface preparation during DIY projects. Ensure the surface is thoroughly cleaned and free of debris or moisture before application begins. Failing to do so can compromise the membrane’s effectiveness.

Another common mistake is applying too thin a layer or ignoring drying times. Always follow instructions very carefully to ensure proper curing and to avoid costly repairs down the line.

Step-by-Step Guide: How to Apply Liquid Based Waterproofing Membrane

If you are considering DIY application or simply want to learn more about the process, here’s a step-by-step guide for applying liquid waterproofing membranes.

1 – Surface Preparation

Clean the surface before you do anything else. This could involve removing dust, dirt, grease, and any loose material. Clean until the area is dry, smooth, and free of cracks or holes (fill or repair these if needed).

2 – Primer Application

There are different types of primers depending on the surface and membrane system you’re using, including water-based, epoxy, or polyurethane primer. If unsure, ask a knowledgeable staff member from your hardware store when purchasing your liquid membrane. Then, apply a suitable primer to improve adhesion between the membrane and the surface. Allow the primer to dry fully according to the manufacturer’s instructions before applying the liquid membrane.

3 – First Coat

Using a brush, roller, or sprayer, apply the first coat of the liquid membrane evenly across the surface, paying special attention to corners and joints.

4 – Mesh/Fabric Reinforcement (if applicable)

This is an extra step for areas prone to movement or cracking. You can embed reinforcing mesh or fabric into the wet first coat to strengthen the membrane.

5 – Second Coat

Once the first layer has dried, apply the second coat perpendicular to ensure complete, seamless coverage and maximum waterproofing performance.

6 – Curing Time and Inspection

Allow the membrane to cure fully, following the recommended drying time. Once cured, inspect the surface for consistent coverage and touch up any missed areas if needed.

Liquid Membrane Cost and Affordability Considerations

How much your liquid waterproofing membrane costs largely depends on the size of the project, product type and surface area. Polyurethane and liquid rubber options are typically more expensive than acrylic or bituminous products because they offer superior flexibility and durability.

If you hire a professional, then you will need to factor labour costs into your budget. But also keep in mind that you’re paying for expert preparation, application, and long-lasting results. Most of all, you are paying for peace of mind. And while the upfront investment can feel like an unwanted expense, factor in the long-term savings and having the job done properly.

Tips to Maintain Liquid Applied Waterproofing Membranes

To get the most longevity from your waterproofing, regularly inspect the membrane for cracks, blisters, or worn areas after heavy rain or extreme weather. Try to get into the habit of keeping the surface clean and free of debris. This also allows you to spot any damaged areas. If you do spot minor damage, patch it promptly with any leftover liquid membrane you have. For larger issues, it’s best to call in a professional.

Where to Find Liquid Waterproofing Membrane

Whether you’re a homeowner, DIY enthusiast, builder, or project manager, liquid waterproofing membranes will provide you with seamless coverage and long-lasting protection. But using the right, high-quality product and applying it correctly can make all the difference.

Contact Illawarra Industrial Supplies today for a free quote and expert advice on the best waterproofing solution for your project.

Frequently Asked Questions

How do you apply liquid membrane waterproofing?

Clean and prime the surface, then apply the liquid coating in two coats with a brush, roller, or sprayer, allowing each layer to dry fully.

Should I use liquid or sheet-based waterproofing?

Liquid membranes are better for complex or uneven surfaces, while sheet membranes work well on large, flat areas, such as roof repair projects.

What is the waterproofing membrane and how is it applied?

A waterproofing membrane is a protective layer that blocks water, applied as either a liquid or a sheet over prepared surfaces. It can be used for waterproofing concrete or as an extra waterproofing layer for a new or existing roof.

What is a liquid waterproofing membrane?

It’s a liquid-applied type of waterproofing system, a coating that cures into a seamless, flexible barrier to protect surfaces from water damage. The liquid membrane can be used on existing surfaces for roof leaks, ground moisture, or wet rooms such as bathrooms.

What are the pros and cons of liquid waterproofing membranes?

The liquid system offers seamless, flexible coverage and easy application. They bond well to cement board, wooden substrates, and swimming pools. Additionally, liquid membranes have excellent resistance to harsh weather conditions and are UV stable. The cons are that liquid membranes require proper surface prep and drying time for best results.