ARDEX ARDIFIX is a two-part polyurethane repair compound for cracks, control joints, spalls and pop-outs on interior or exterior applications. It is ideally suited to seal off cracks and saw-cuts prior to the installation of ARDEX MC™ Moisture Control Systems, Underlayments and Toppings. ARDEX ARDIFIX is ultra fast setting allowing the installation to proceed within minutes of application. ARDEX ARDIFIX is 100% solids for no shrinkage and cures to a rigid hardness. It also has a wide service temperature range of 0°F to 110°F (-17 to 43°C), making it suitable for applications from freezers to warehouses.
The term “fixing cracks” is a bit misleading since there is no way to “fix” cracks in concrete, only fill them. The proper term to use when treating cracks prior to placement of a decorative overlay is “bridging.” This is accomplished by filling or covering the crack with a rigid material so it becomes flush or slightly higher in elevation than the surrounding surface. (Avoid soft, flexible crack fillers.)
To prepare the crack for repair, use a crack-chaser diamond blade to remove any loose concrete and to straighten out the crack as much as possible. The repair material filling or covering the crack needs to bond tenaciously to the concrete surface can be applied so that it gradually feathers down to surface level. The crack filler also needs to bond well with the overlay, so it needs to have a rough profile. The three most common methods for bridging cracks prior to applying a decorative overlay are:
- Rigid Epoxy Systems – These are usually two-part epoxies available in self-mixing cartridges or for mixing onsite. You apply them using an injection gun or putty knife to fill the crack to overflowing, and then you feather out the epoxy on either side of the crack anywhere from 2 to 5 inches (see photo). Placing mesh tape into the wet epoxy provides additional reinforcement. Once the epoxy begins to set, course sand is cast onto it to provide a rough bonding surface for the overlay.
- Cement-Based Systems – Polymer-modified cement-based repair mortars are mixed onsite and applied with a trowel or putty knife (again, using the feathering technique). Multiple thin applications are usually required to avoid shrinkage cracking. To provide a good bonding surface for the overlay, roughen the surface by scratching it with a broom or trowel as it begins to set.
- Crack Suppression Mats – These have been used successfully for years in the tile industry. Roll out the mat to cover the crack by 5 inches on either side (or cover the entire surface if cracking is extensive), and adhere the mat to the surface using a bonding primer or glue. This type of crack suppression method is also a great way to cover seams when applying decorative overlays over wood and other non-concrete surfaces.
ARDEX EP 2000™ is a solvent-free, low viscosity, two-component, 100% solids epoxy resin primer formulated for use with ARDEX underlayments and toppings. It is especially suited to prime concrete and other structurally sound and solid substrates, including terrazzo, epoxy coatings and ceramic and quarry tile, prior to installing ARDEX products.
ARDEX EP 2000 is the required primer for the following ARDEX flooring systems: ARDEX Designer Floors™ using ARDEX SD-T® Self-Drying, Self-Leveling Concrete Topping; the ARDEX Polished Concrete System (APCS) using ARDEX PC-T™ Polished Concrete Topping.
ARDEX P 51™ is a solvent-free primer that improves the adhesion of ARDEX products over standard absorbent dry concrete substrates, as well as over other substrates in specialized applications.
ARDEX K 15 is a Portland cement-based, self-leveling underlayment formulated with a special blend of polymers used to level and smooth interior concrete, terrazzo, ceramic and quarry tile, metal, wooden substrates and non-water soluble adhesive residue on concrete prior to the installation of finished flooring – on, above or below grade. It can also be installed over concrete treated with certain curing compounds (see below). Designed specifically for the fast leveling of floors, ARDEX K 15 provides a durable, flat, smooth floor surface with minimum labor and installation time. It is pourable or pumpable when mixed with water, and seeks its own level to produce a smooth, flat, hard surface. ARDEX K 15 is also recommended and specified by many quality flooring manufacturers, architects and contractors.
SUBSTRATE PREPARATION EPOXY. Follow the general recommendations for substrate preparation above, and apply the ARDEX EP 2000 with sand broadcast, carefully following the instructions given in the ARDEX EP 2000 Technical Brochure.
ARDEX CG™ is a high-performance, high solids concrete sealer that is easy to apply, quick drying, nonflammable and UV stable. Applied at a minimum of two coats, ARDEX CG is designed to protect all interior and exterior absorbent concrete and masonry surfaces on residential and commercial applications, including driveways, sidewalks, patios, courtyards, walkways, pool decks and most vertical concrete surfaces. It is especially suited to seal ARDEX toppings, and the gray version can be used to create a uniform appearance over both a repaired area and the adjacent concrete or masonry surfaces.