‍If you’re a homeowner, protecting your property from water damage is of utmost importance. One area that requires special attention is your roof, especially if it is tiled. Properly waterproofing a tiled roof is crucial to prevent leaks, structural damage, and the growth of mould and moss. In this comprehensive guide, we will walk you through the step-by-step process of how to waterproof a tiled roof effectively.

Step-by-Step Guide to Waterproofing a Tiled Roof

Step 1: Substrate Preparation

Before starting the waterproofing process, it’s crucial to prepare the substrate properly. Ensure that the roof’s concrete surface is dry, clean, and free from loose particles, dust, and grease. Any cavities or cracks in the concrete should be filled with a suitable repairing mortar, such as the polymer-modified, fibre-reinforced DUROCRET-PLUS.

Step 2: Surface Priming

To enhance the adhesion between the substrate and the waterproofing membrane, apply a suitable primer. The choice of primer depends on the moisture content of the substrate. If the moisture content is below 4%, use a one-component polyurethane primer like PRIMER-PU 100. If the moisture content is higher, opt for a two-component polyurethane primer like PRIMER-PU 140.

Step 3: Application of Waterproofing Membrane

The next step involves applying the waterproofing membrane onto the tiled roof. The ideal product for this purpose is the one-component polyurethane waterproofing liquid membrane, ISOFLEX-PU 500. This product offers excellent flexibility, adhesion, and durability, ensuring a strong and continuous waterproofing layer.

To apply the ISOFLEX-PU 500, stir the product gently until it becomes homogeneous. Avoid excessive stirring to prevent air entrapment. Apply the membrane in two layers, allowing the first layer to dry for 2-3 hours before applying the second layer. The consumption of the ISOFLEX-PU 500 is approximately 1.0-1.5 kg/m².

Step 4: Reinforcement with Polyester Fleece

For added strength and reliability, it is recommended to reinforce the waterproofing membrane with polyester fleece along critical areas such as junctions with vertical elements, pipe joints, ventilation joints, and metal element joints. Apply a coat of the ISOFLEX-PU 500 along the designated areas and embed a 10 cm wide strip of polyester fleece. Apply a second coat of the membrane after 8-24 hours, followed by a third layer in the areas requiring reinforcement.

Step 5: Thermal Insulation and Tile Installation

After completing the waterproofing process, you can proceed with the installation of thermal insulation and tiles. Depending on the type of insulation, follow the manufacturer’s instructions for proper installation. For fixing the roof tiles, use a strong cement mortar mixed with ADIPLAST polymer latex to enhance bonding.


Properly waterproofing a tiled roof is essential to protect your home from water damage, ensure the longevity of your roof, and maintain a safe and healthy living environment. By following the step-by-step guide outlined in this comprehensive article, you can effectively waterproof your tiled roof and enjoy peace of mind during rainstorms. Remember to use high-quality materials and seek professional assistance if needed. Invest in roof waterproofing today and safeguard your home for years to come.

For professional roof waterproofing services in Melbourne, Australia, contact Melbourne Roofers. Our team of experts is dedicated to providing top-notch roofing solutions, including roof repair, metal roofing, roof restoration, and guttering. Visit our website to learn more about our services and get in touch with us today.