Waterproof Flat Concrete Roof

How to a Repair Leaking Concrete Roof (Melbourne Case Study)

Remedial Waterproofing to Leaking Concrete Rooftop

Video - Case Study

Video below explains how Findlay-Evans Waterproofing rectified water leak problems for this challenging rooftop, which also involved difficult access for the Team and equipment.

Project: Badly deteriorated waterproof membrane causing water leaks in concrete roof slab

See More Findlay-Evans Waterproofing Case Study Videos HERE

Best Membrane for Concrete Roof Slab

Findlay-Evans Waterproofing recently completed a particularly challenging roof remedial waterproofing project close to Melbourne CBD.

As shown in the image above, the height and condition of the existing roof made access difficult.

However all our Team are "Working at Heights" & "Confined Spaces" compliant.

And our spray apply waterproofing system is mobile and easily transported to rooftops.

The Team successfully installed - on time and on-budget - a UV stable waterproof membrane on a concrete slab roof.

Prior to the new membrane, this rooftop had an extremely deteriorated existing polyurethane roof sealant that was causing quite extensive water leaks.

Preparing Concrete Surface Prior to Waterproofing 

It is extremely important to prepare and clean any surface meticulously before applying a new waterproofing membrane.

Our Team had to complete extensive preparation to the badly leaking and deteriorated concrete substrate prior to spray-on application of a Liquid Rubber Membrane.

  • Our Waterproofing Team was the nominated waterproofing contractor to provide a permanent solution for a membrane to fix a leaking concrete roof for a commercial large flour mill.
  • While the actual roof substrate was still in good condition, the existing polyurethane membrane was in a very poor state allowing water to penetrate through the concrete roof
  • To ensure a permanent waterproofing solution for this roof, we started off by removing the old defective membrane by using mechanical scrapers.
  • Once the deteriorated polyurethane membrane was removed, we then proceeded to cleaning the concrete roof to ensure a good adhesion for the new Liquid Rubber Membrane

Existing failed roof membrane

Removal of existing failed membrane prior to installation of new LIQUID WATERPROOFING.

Roof membrane prior to remedial work by the crew at Findlay-Evans - See our Client Testimonials HERE

Waterproofing Method for Flat Concrete Roof 

  • Although the existing concrete roof was in good order,  in general there were some areas that required rescreeding and leveling out to create a sound roof substrate. 
  • We went ahead and screeded these areas with flexible screed, and then coated with Liquid Rubber waterproofing membrane. 
  • The entire concrete roof was coated with Liquid Rubber including an interlacing fiberglass mesh to make the membrane even more robust.
  • As this building was particularly big, there was a lot of movement and therefore Liquid Rubber was the ideal solution to waterproof this flat roof and stop water leaks. 

Best Waterproofing Product for Roofs 


Liquid Applied Waterproof coatings have become the industry standard to seal leaking concrete and metal roofs.

Using flexible and monolithic Liquid Rubber membranes.

Liquid Rubber is highly flexible waterproofing membrane. This allows for building movement; contraction, expansion and vibration.

Spray On Waterproofing - Liquid Membranes

  • To finish off the final membrane we roller applied two coats of the heat reflective Thermo Top Coat in light grey colour. 
  • Thermo Top Coat is not only pleasing to the eye but also provides thermal properties reducing the interior temperatures by up to 8 Celsius degrees. This helped with the internal ventilation keeping the building cool inside during the summer months.
  • The project turned out great everybody being happy with the outcome.

Liquid Rubber & Thermo Top Coat 

Thermo Top Coat - an over coating system to be used in conjunction with Liquid Rubber to reduce interior temperature.  

Melbourne Waterproofers - Australian Institute of Waterproofing

See More Findlay-Evans Waterproofing Case Study Videos HERE

What Our Clients Are Saying 

View Testimonials - HERE

Roof Repairs - Remedial Waterproofing

The Australian Institute of Management (AIM) recently engaged F.E.W Waterproofing to resurface the Level 6 plant area which was prone to water leakage. 

Liquid Rubber was used and is brilliant seamless product; we were very impressed with the finished product.

The F.E.W workmanship was of a high standard. Since having the Liquid Rubber laid down we have not experienced any water leaks.

D. Papal Australian Institute of Management (Vic & Tas) Building Manager 

Find Out How Commercial Waterproofing Company in Melbourne Stop Water Leaks in This Concrete Roof Slab 

Melbourne-waterproofing-concrete-roof-slab
waterproof sealer for concrete -roof-slab

Liquid Rubber Waterproofing Membrane 

Waterproofing System ideal for concrete rooftop membranes - permanently stops water leaks. Listen to Audio Case Study Below.

Read more. Findlay-Evans Recent Projects