Waterproofing
Liquid membranes, cement based waterproofing mortars, butyl tape and reinforcing cloth from Ardex, Mapei, Sika and Davco for showers, bathrooms and balconies under tile.
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Why choose Multifors for waterproofing?
Under tile
Made for wet areas
Liquid and cementitious membranes go over the substrate and under the tile bed in showers, bathrooms and balconies.
Speed
Keep the tiling moving
SikaTile-111 Rapid Proof is ready for tiling about 3 hours after the final coat, and Ardex WPM155 Rapid Plus after 3 to 4 hours at 23°C.
Details
Reinforce the weak points
Ardex Deckweb cloth builds membrane thickness at cracks, movement joints, corners and wall to floor junctions.
Flexibility
Membranes that move
Flexible membranes such as Mapei Mapelastic Smart bridge small cracks as the substrate moves, where a rigid coating can crack.
About Waterproofing
A waterproofing membrane is a continuous layer applied over the substrate and under the tile bed to stop water getting through to the structure. Tiles and grout alone do not do that job, so showers, wet area floors and balconies rely on a membrane built up to the right thickness, with extra reinforcement at corners, joints and pipe penetrations.
Liquid membranes are brushed, rolled or trowelled on in coats. All five carry a Class III elongation rating, the most flexible class: SikaTile-110 Secure Proof complies with AS/NZS 4654:2012 and AS 4858:2004, SikaTile-111 Rapid Proof and Ardex WPM155 Rapid Plus are tested to both, Davco K10 Plus holds BRANZ reports for both, and Ardex Superflex WPM002 is tested to AS 4858 only, so it is not the one for an exposed balcony or roof. The range includes SikaTile-110 Secure Proof, SikaTile-111 Rapid Proof, Davco K10 Plus, Ardex WPM155 Rapid Plus, Ardex Superflex WPM002 and Mapei Mapelastic AquaDefense. Drying time before tiling varies widely. Mapei allows tiling 4 hours after the second coat of AquaDefense at 23°C and 50% humidity, using a C2 class adhesive. Ardex gives 24 hours at 23°C before tiling over Superflex WPM002.
Cement based products suit different jobs. SikaLastic-1K is a fibre reinforced, crack bridging mortar for bathrooms, showers and swimming pools before tiling. Mapei Mapelastic Smart is a two-part flexible cementitious membrane for balconies, terraces and bathrooms. Mapei Planiseal 88 is an osmotic mortar for concrete and masonry facing water pressure from behind, such as a below-ground wall or tank. Ardex Deckweb cloth and 80mm butyl tape reinforce corners, cracks and wall to floor junctions.
Common Questions
Waterproofing FAQ
Do I need a membrane in a shower?
Yes. Tile and grout are not a water barrier on their own, so a shower needs a membrane over the substrate before the tile bed goes down, with tape or cloth at corners, joints and penetrations. Where waterproofing must go is set by building rules and AS 3740. Check local building requirements, and use a licensed waterproofer where the law requires one.
What does AS 3740 cover?
AS 3740 is the Australian Standard for waterproofing of domestic wet areas such as showers, bathrooms and laundries. It deals with where waterproofing is needed and how junctions and penetrations are detailed. A product’s data sheet tells you how to apply that product, while the standard and your building surveyor set where waterproofing must go. Rules on who can do the work differ, so check local requirements.
How long before I can tile over a membrane?
It depends on the product, temperature and humidity. Fastest are SikaTile-111 Rapid Proof at 2 to 3 hours after the final coat and Ardex WPM155 Rapid Plus at 3 to 4 hours at 23°C. Mapelastic AquaDefense allows tiling 4 hours after the second coat, using a C2 class adhesive. SikaTile-110 Secure Proof needs 6 to 8 hours, and Ardex Superflex WPM002 needs 24 hours at 23°C.
How thick should a liquid membrane be?
Thickness, not just coverage, is what gives a membrane its rated performance, so apply every coat the data sheet asks for. Sika, which now makes Davco K10 Plus, specifies a minimum dry film thickness of 1.0mm, built up in at least two coats. SikaTile-110 Secure Proof builds to a 1mm minimum dry film, and Ardex WPM155 Rapid Plus goes on in at least two coats of 0.5mm wet film.
Can I apply a membrane to damp concrete or a below-ground wall?
Some cement based products are made for it. SikaLastic-1K is used for concrete tanks as well as wet areas. Sika lists it as able to go onto damp substrates, but its instructions still call for a surface that is not moist to the touch, so check the data sheet. Mapei Planiseal 88 is an osmotic mortar that works against water pressure from behind, such as on a basement wall or tank, and is rated for contact with drinking water. Check each data sheet for substrate moisture limits.
Waterproofing a shower or balcony?
Our team can help you compare membranes, drying times and reinforcement for your substrate and tiles. Get in touch for expert advice, and check local building requirements for who must carry out the work.
Get in touch for expert advice, samples and trade pricing.