Ardex WPM 300 is a two-part water based epoxy coating designed as a preparatory sealer and barrier coat. HydrEpoxy WPM 300 prepares otherwise incompatible or problem surfaces prior to the application of surface coatings such as paint, texture coatings and waterproofing membranes.  

Ardex WPM 300 effectively safeguards the final finish from being adversely affected by moisture and prevents problems such as:

• Blistering of paint and texture coating finishes
• Poor top coat adhesion
• Drummy render
• Poor masonry bonding
• Efflorescence
• Crumbling substrates HydrEpoxy WPM 300 also enables new/green concrete or render to be top coated with minimum delay  

Sealing Against Efflorescence

PREVENTING SALTS  

Efflorescence is the migration of salts from concrete, bricks, masonry and pavers that either form a powder or crystallise on the surface. These salts will migrate through tile adhesives, paint and texture coatings causing discolouration and in severe cases can result in the total breakdown of the applied top coating. This effect is exacerbated when the substrate is not totally dry before application of the top coating. HydrEpoxy WPM 300 can be used to prevent the effect of efflorescence forming on the surface of paint, texture, tiles and other coatings.  

TO PREVENT IT

• Remove any coatings, dirt and loose salts from the substrate.
• Apply one coat of HydrEpoxy WPM 300 by brush or roller, at a coverage rate of 3 square metres per litre.
• Allow HydrEpoxy WPM 300 to dry overnight.
• Apply desired top coatings.  

Bonding New To Old Concrete or Render

A BETTER FOUNDATION When applying new concrete or render onto aged concrete it is very important that a sound, firm bond is achieved between the two materials. HydrEpoxy WPM 300 forms a structural high strength bond between new concrete/render and aged concrete. Use of HydrEpoxy WPM 300 eliminates the risk of ending up with drummy render or poorly bonded concrete.  

TO FIX IT

• Remove any coatings, dirt and loose material from the substrate.
• Apply one coat of HydrEpoxy WPM 300 at a coverage rate of 3 square metres per litre.
• Whilst the HydrEpoxy WPM 300 is still wet and tacky, lay the new render or concrete topping.
• Should the HydrEpoxy WPM 300 go hard before the render/concrete can be laid simply apply a further coat of HydrEpoxy WPM 300 and apply top coating.  

Internal Sealing Of Subterranean Surfaces

RESISTING HYDROSTATIC PRESSURE  

A common problem with walls and floors that are effectively underground or have earth back-fill against the external surface is that they range from being always damp to water seeping through them. The water develops a pressure against the external surface equal to the height of the back-fill or the depth the wall is underground. This pressure is referred to as a head of water and forces water through the wall. In many areas of Australia the water table is very high resulting in water seeping through the floor due to capillary action.  

TO FIX IT

• Apply HydrEpoxy WPM 300 directly onto the internal wall substrate, which must be clean and free from any dirt and surface coating.
• HydrEpoxy WPM 300 should be applied in 2 coats at a maximum coverage rate of 3 square metres per litre per coat to seal off water against hydrostatic pressure of up to 25-metre head of water.
• Allow to cure for 2 days (48 hours) before applying desired top coating to wall or floor.  

New (Green/fresh) Concrete Or Render

WHY WAIT AROUND?  

Normal practice is to allow new concrete to cure for 28 days and render for 7 days, before the application of surface coatings such as paint, texture coatings, levelling compunds and waterproofing membranes. With HydrEpoxy WPM 300 these coatings can be applied to new concrete/render so long as the latter is hard enough to coat (generally after 16 hours). In fact HydrEpoxy WPM 300 offers the benefit of acting as an effective concrete curing membrane, which means less risk of cracking, shrinkage and optimum strength of the finished concrete.  

TO FIX IT

Clear the surface of dust and other contaminants.

• Apply 1 coat of HydrEpoxy WPM 300 by brush or roller at a coverage rate of 3 square metres per litre.
• Allow HydrEpoxy WPM 300 to dry overnight.
• Apply surface top coating such as paint, texture coatings, waterproofing membranes, levelling compunds, tile adhesives etc. NB: HydrEpoxy WPM 300 is a surface preparation product and must not be left exposed to UV rays for extended periods.  

Wet Concrete Or Render

RENOVATORS TAKE NOTE When renovating bathrooms, or other internal wet areas, the underlying substrate is usually wet and at times saturated. Applying a top coating to such a substrate causes blistering, drying and/or adhesion problems, which can ultimately lead to a breakdown of the applied top coating. An option is to wait for the substrate to dry, resulting in expensive delays especially in a fast track commercial project situation. Similar problems can be experienced when applying paints or texture coatings in external applications.  

TO FIX IT

• Remove all surface water.
• Apply one coat of HydrEpoxy WPM 300 by brush or roller at a coverage of 3 square metres per litre. Allow HydrEpoxy WPM 300 to dry overnight.
• Apply desired top coating eg. paint texture coatings, waterproofing membranes etc. 

Sealing Rising Damp

THE BLIGHT OF MANY AN OLD HOUSE 

Rising damp caused by moisture from the ground coming through brick and masonry walls, results in major problems when tiling, painting or wallpapering. Rising damp manifests through blistering paint, crumbling plaster etc. Once rising damp is addressed through fixing the damp course the substrate is coated with HydrEpoxy WPM 300 before the surface is painted, tiled or wallpapered. HydrEpoxy WPM 300 can be applied to concrete, render, bricks, stone or other solid substrates. HydrEpoxy WPM 300 is not recommended for use over plaster, gyprock or over concrete walls with reinforced steel. For areas subject to hydrostatic pressure when wall is below ground level refer to section "Internal Sealing of Subterranean Surfaces".  

TO FIX IT

• Fix the damp course.
• Remove existing coatings to ensure proper bonding of HydrEpoxy WPM 300 to the substrate.
• Apply one coat of HydrEpoxy WPM 300 by brush or roller at a coverage rate of 3 square metres per litre and allow to dry overnight then apply top coating. NB: Do not treat both sides of a wall with HydrEpoxy WPM 300, as moisture must be allowed to escape.