Minor cracks in a concrete floor should be repaired before applying an epoxy coating or resurfacing system. If they are left open, the crack can remain visible through the finished floor and may affect the coating around it.
The Dulux Avista Epoxy Concrete Crack Repair Kit is a two-component, low-viscosity epoxy system that is mixed with clean fine sand to form a strong crack-filling mortar. This guide explains the correct preparation, mixing and application process from the current Dulux Avista Technical Data Sheet.
What Is the Dulux Avista Crack Repair Kit?
The kit contains a 1L epoxy base and 500ml hardener. These two components are mixed together before clean fine sand is added, producing approximately 6L of repair mortar.
It is designed for filling minor cracks in concrete before applying compatible Dulux Avista epoxy or resurfacing products.
Key Technical Information
- Components: Two-part epoxy—1L base and 500ml hardener
- Sand requirement: Approximately 4.5L of clean fine sand
- Mixed yield: Approximately 6L
- Pot life: Approximately 25 minutes once mixed
- Cure time: Approximately 12 hours, depending on ambient conditions
- Recoat time: Approximately 12 hours
- Solids by volume: 100%
- Compressive strength: Up to 90MPa
- Application: Pour or apply with a trowel
Before You Begin: Check Whether the Crack Is Stable
This repair is intended for minor concrete cracks. The Dulux Avista Technical Data Sheet warns that cracks may reappear if the surface is unstable.
If the crack is widening, moving, uneven in height, allowing water through or may indicate structural movement, determine the cause before filling it. An epoxy repair cannot stop continued movement in the concrete.
What You Will Need
- Dulux Avista Epoxy Concrete Crack Repair Kit
- Approximately 4.5L of clean fine sand
- Angle grinder fitted with a suitable V-segment blade
- Hydrochloric Acid for the acid-washing step, used only as directed on the label and Safety Data Sheet
- Badger Brick Acid Brush for wet scrubbing
- Clean, dry mixing container
- Low-speed drill fitted with a helical mixer
- Trowel
- Additional dry sand for the surface broadcast
- Suitable gloves, eye protection, protective clothing and respiratory protection
Grinding concrete and handling epoxy products can create hazardous dust, splashes and vapours. Use suitable dust control, ventilation and personal protective equipment, and review both component Safety Data Sheets before starting.
How to Repair Concrete Cracks Step by Step
Step 1 — Chase Out the Crack
Before cleaning, open the crack with an angle grinder fitted with a V-segment blade. The current Dulux Avista Technical Data Sheet specifies a channel approximately:
- 10mm deep
- 5mm wide
Chasing the crack removes weak edges and creates a consistent channel for the epoxy mortar.
Step 2 — Clean the Crack Thoroughly
Remove all grinding dust, loose concrete, dirt, oil and other contamination.
Acid wash and pressure clean the prepared concrete using Hydrochloric Acid at the correct dilution and in accordance with its label and Safety Data Sheet. A Badger Brick Acid Brush can be used for controlled wet scrubbing. Rinse the area thoroughly after acid washing.
The crack and surrounding concrete must then be allowed to dry completely. Do not apply the repair material to damp concrete or where moisture remains in the channel.
Step 3 — Prepare Before Mixing
The mixed epoxy has a pot life of approximately 25 minutes, so have the sand measured, the drill and mixer ready, the trowel nearby and the crack fully prepared before combining Parts A and B.
Do not mix the product until the area is ready to fill.
Step 4 — Mix the Epoxy and Sand
- Place the full 1L epoxy base into a clean, dry mixing container.
- Add the full 500ml hardener.
- Mix the two components thoroughly using a drill fitted with a helical mixer.
- Add approximately 4.5L of clean fine sand and continue mixing until an even crack-filling mortar is produced.
The exact quantity of sand may vary slightly with the sand type and the consistency required. Use only clean, fine and dry sand so moisture or contamination is not introduced into the epoxy.
Step 5 — Fill the Crack
Pour or trowel the mixed mortar into the prepared channel. Work the material into the crack so it fills the entire void, then finish it level with the top of the surrounding concrete.
Avoid leaving low spots, air pockets or partially filled sections. Any excess material can be ground flat after the repair has cured.
Step 6 — Apply a Dry Sand Broadcast
Immediately after filling, apply a dry shake of clean sand over the entire repaired area. This creates a coarse mechanical key for a compatible coating or resurfacing product applied later.
Step 7 — Allow the Repair to Cure
Allow approximately 12 hours for curing under normal conditions. Temperature, ventilation and site conditions can change the actual cure time.
Once fully cured, grind any excess repair material flush with the surrounding floor if required. Remove all dust before proceeding with the next approved coating system.
What Can Be Applied Over the Repair?
According to the Dulux Avista Technical Data Sheet, the cured repair can be overcoated with:
- Dulux Avista Resin Epoxy
- Tinted Dulux Avista Waterbased Epoxy
- Dulux Avista Resurfacing products
Important: The Crack Repair Kit is not to be used under clear or coloured concrete sealer. The repaired area may remain visible through a clear system, and these sealers are specifically excluded by the Technical Data Sheet.
Common Mistakes to Avoid
- Filling an active or moving crack without addressing the cause
- Skipping the 10mm-deep by 5mm-wide preparation channel
- Applying epoxy to damp concrete
- Leaving grinding dust or contamination inside the crack
- Using wet, dirty or coarse unsuitable sand
- Changing the 1L base to 500ml hardener ratio
- Mixing before the site and tools are ready
- Trying to use the mortar after its approximately 25-minute pot life
- Forgetting the dry sand broadcast where the repair will be overcoated
- Using the repair beneath clear or coloured sealer
Safety and Storage
Both epoxy components have their own Safety Data Sheet. Read each document before use and follow the stated personal protective equipment, ventilation, first-aid and disposal requirements.
- Avoid skin and eye contact
- Do not breathe dust or vapours
- Use appropriate gloves, eye protection and protective clothing
- Control concrete dust when grinding
- Keep mixed and unmixed materials away from children
- Do not allow product or wash water to enter drains or waterways
The unopened kit has a stated shelf life of up to five years when stored in its original packaging under the dry temperature and humidity conditions specified in the Technical Data Sheet.
Technical Documents
- Dulux Avista Epoxy Concrete Crack Repair Kit Technical Data Sheet
- Dulux Avista Epoxy Crack Repair Base Safety Data Sheet
Repair Minor Cracks Before Coating
Correct preparation is what makes this repair system effective: chase the crack, clean it thoroughly, let it dry, measure the components correctly and complete the repair within the available working time.
Shop the Dulux Avista Epoxy Concrete Crack Repair Kit at Gippsland Concreting Supplies, or contact our team for help selecting a compatible Avista coating system for the repaired floor.
