Q: How best to detect source of a leak on a balcony?
A: First block drain outlets and create bund on edges
Use hose to fill area and apply non-hazardous dye.
Observe sides/underside of substrate to locate leakage.
Q: What is the best membrane product to use and how do they differ?
A: Acrylic paint on products is most widely used due to application ease.
Polyurethanes perform well: may need to blitz with sand to enable further adhesion.
Cementitious membranes offer the advantage of negative protection.
Q: How long should a coating last?
A: Depends on exposure to the elements, and method of application and maintenance program. Waterproofing membranes are tested for aging under AS4654.2.
Q: What guarantee should I expect?
A: A manufacturers warranty will apply for products tested to an Australian Standard. A separate warranty may be obtained by a contracted applicator.
Q: Should a primer be used in all circumstances?
A: Primers assure adherence. A diluted solution of acrylic membrane can serve as a primer.
Q: What is a bond-breaker?
A: Breaks the bond between substrate and membrane creating flexible elastic bridge that can stretch and move to accommodate building movement.
Q: What is the minimum fall required for an outside balcony/slab?
A: The minimum fall is 1:80 ratio.
Q: How many coats should I apply?
A: Minimum of two coats.
Q: What is the interval between coats?
A: Follow the manufacturer’s guidelines.
Q: Why should I use polycloth tape?
A: Provides strength and flexibility to the membrane when applied over joints.
Q: What is the best means to ensure tile adhesive sticks to membrane?
A: Use a compatible adhesive. Follow manufacturer’s recommendation.
Q: Can I apply a clear coating over my tiles to stop water leaks?
A: No. However, you may apply a clear water repellant which will provide an improved water-tight balcony.
Q: Is there a sealer to protect against oil stains?
A: Protect Natural Sealer is one of the few products available in the marketplace with these characteristics. Protect Natural Sealer and similar products contain ingredients which are banned in some countries. Hence availability going forward requires new technology to offer the same protection.
Q: How many coats should be applied to (a) green concrete (b) old concrete?
A: Minimum of two coats.
Q: Do I need to acid wash in all circumstances?
A: An acid wash is a last resort where cleaning is concerned. Usually a commercial grade detergent, brush and high-pressure hose will remove most stains. Degreaser if needed.
Q: When should I use an epoxy coating or a penetrating coating?
A: Epoxy coatings are recommended in food preparation areas & showrooms that require a high-quality finish. Penetrating sealers are best suited to factory & roadway applications.
Q: Why are epoxy coatings so expensive?
A: Premium quality demands a premium price.
Q: How often should the coating be renewed?
A: Recoating will depend on the product type and application. Each surface substrate will require ongoing care & maintenance. Normal wear & tear should allow a serviceable life of 4-10yrs.
Q: Can I apply a penetrating sealer over a painted surface?
A: No. The active thinners in the sealer will delaminate the paint. Paint surfaces must always be removed.
Q: Why use a proprietary product in lieu of sand cement Bond Crete mix?
A: Specialist products contain stronger adhesives and polymers not found in regular cement mixes.
Q: What’s the minimum depth of a repair screed?
A: Screeds can be as shallow as two millimeters, with a fall to feather edging. Select a screed that best fits purpose.
Q: Can I mix sand with a proprietary product to extend coverage?
A: Not recommended. Will compromise product performance.
Q: Why have cracks appeared in my screed?
A: Excess water in mix. Environment too hot to enable proper cure.
Q: How do I prevent moisture rising from the substrate through my screed?
A: Apply an epoxy moisture barrier to substrate.
Q: What is the difference between cementitious and epoxy products?
A: Cementitious products are usually used for general repairs. Epoxy products are best suited where stress and strength are an imperative.
Q: Where would I use the latter?
A: In heavy traffic areas and edges where stress is applied.
Q: Is a primer required when applying a screed?
A: Where substrate is in disrepair a primer is essential. Otherwise, a clean well-presented surface will suffice.
Q: What’s the difference between internal and external self-levelling compound?
A: Generally self-levelling compounds are suited only to internal use. Where external applications are concerned ensure you purchase a reputable product endorsed by the manufacturer for that use.
Q What is bony concrete and how can it be repaired?
A: Bony concrete occurs when the mix has excess water and/or the mix has not been tamped correctly. The offending area should be replaced.
Q: How do I repair rusted steel rods and concrete cancer?
A: There are proprietary products that will deal with these conditions. Seek advice from your local supplier.
Q: How do I calculate consumption of an aggregate mix for a given area?
A: Multiply the area by the average depth of your screed. Convert to litres and refer to the manufacturer’s instructions which will provide a weight/litres guideline.