The Australian Waterproofing Defect Crisis

What Is The Crisis?

Australian construction is amidst a huge overhaul in standards relating to the way buildings are constructed since the evacuation of both the Opal towers and Mascot towers in Sydney. Unfortunately this is just the tip of the iceberg in relation to the the Australian building boom where to date over 700,000 apartments blocks have been built nationwide.

The Most Common Problem

Waterproofing has topped the list by every law firm and governing body as the main cause of defects in the construction industry where builders have had to fork out over $500 million dollars in damages for defective building work.

The Mentality That Has Brought Us Here Today?

Often in construction Project Managers are set on to provide a cost effective build and save on money where possible to create a cost managed project which is understandable. In doing this most project managers wether that be lack of knowledge or ethics are treating waterproofing with the same cost management as lower risk packages which really does leave a builder at a much higher risk of damages later down the track. Lets take a look at a head to head scenario with the Fatra PVC Membrane VS Liquid Debate. Although liquid and spray applied membranes are a great concept in theory, they just haven’t hit the durability that they once promised. They are proving to be the spearhead in waterproofing defects due to many reasons, and we will compare how the Fatra PVC membranes deal with these issues:

Membrane Thickness

Liquid - The membrane for example will most likely need to be applied at a 1.5mm thickness across the whole substrate and you have a man with a roller and a pole attempting to do this out of a bucket? Is this honestly realistic? And if he fails to do this your warranty is gone! Add this to cost squeezing from project managers and we have a formula for who is willing to produce the lowest quality job and take the risk. Often, I believe the project manager is thinking that these guys hold the warranty if anything goes wrong anyway? Well think again, as waterproofing companies have the highest rates of wind down than any other trade in Australia.

Fatra PVC - Being factory manufactured, they are rigorously checked through QA to ensure they achieve the minimum film thickness giving no way out for a supplier to void warranty based on this. There is no possible human error in this situation.

Substrate Moisture

Liquid - If a liquid membrane is applied to a substrate with moisture above the required rates, which varies for each product, then over time the membrane will blister / tear and defect. You will more often than not see waterproofers who don’t even own a moisture meter let alone use one. Therefore the risk increases, add the cost squeezing he has received at contract negotiation this guy is likely to take a punt leaving you to hold the batten.

Fatra PVC - Fatra offer 3 different solutions from an anchoring perspective :

Fully Adhered : The Fatra fully adhered systems are applied using a MOISTURE curing polyurethane adhesive making it very difficult to have issues in this system and impossible for the system to defect from a waterproofing perspective.

Mechanically Fastened : Unaffected by substrate moisture, Fatra PVC membrane are vapour permeable from inside out only meaning they will breathe away minor moisture.

Ballasted : This method uses weight to hold the membrane to the roof area as above the membrane can breath vapours outwards and will not be affected by substrate moisture.

Structural Cracking

Liquid membranes come with the great seller of often over 400% elongation with the theory sounding bullet proof.

Do your own very simple tests and compare to the Fatra PVC sample?

Liquid Membrane

• Take a sample of the membrane and apply moderate pressure pulling it apart for 30 seconds. Often it will tear in less than 10 seconds.
• Apply less pressure to the membrane and observe? The membrane stretches thinning the membrane and not reforming back to its original shape. Add continual building movement which happens daily and you have a cocktail for failure.

Fatra PVC

• Apply as much pressure as you want and assuming you are not related to the incredible hulk or captain America this membrane is not going to tear.
• If you have structural movement joints fatra provide simple and easy site specific expansion joint details for relative movement.

Conclusion

Liquid membranes are the primary failure of all waterproofing issues and are costing builders huge sums of money in rectification. Many builders are analysing the trend and seeing the changes coming, understanding it’s not just legal costs and defect rectification but also the commercial costs of time spent dealing with these issues. In reality the saving on paper is unlikely to create a saving over all.