Epoxy is popular for garage floors and decorative resin floors because it can produce a hard, easy-to-clean surface. It is also unforgiving. Most failures trace back to poor preparation, moisture in the concrete, or rushed mixing and application. This guide explains how DIY epoxy work usually goes and where the risks are.
What DIY epoxy covers
“DIY epoxy” usually refers to one of two things:
- Coating kits for concrete floors, most often garage floors, sometimes basements. These are applied thinly in one or two coats, often with decorative flakes and a clear topcoat.
- Pour-on or casting resins, used for decorative floors, tabletops and art. These are applied thicker and in batches.
The preparation principles are similar, but always follow the specific product’s data sheet, since temperature limits, mix ratios and cure times vary.
Is epoxy a good fit for your floor?
Epoxy tends to suit clean, sound, dry concrete. It is a poor choice over a floor that has persistent moisture, heavy oil contamination that cannot be removed, crumbling concrete, or a failing old coating. Also consider whether you will be able to keep the room at the product’s required temperature for the application and cure period.
Disadvantages of epoxy flooring
- Preparation is demanding. Skipping grinding or etching is a common reason for peeling.
- Moisture sensitivity. Moisture vapor coming up through concrete can cause bubbling or delamination.
- Slippery when wet. Smooth coatings can be slick; anti-slip additives are often used.
- Hot-tire pickup and scratches. Some coatings are vulnerable to these, particularly cheaper kits without a protective topcoat.
- Limited working time. Mixed epoxy cures on its own schedule, so there is little room for delay.
- Hard to remove. Removing a failed coating can mean grinding.
- Yellowing. Some epoxies discolour in sunlight, which is why topcoats are often used.
Safety first
Epoxy work involves chemicals and dust.
- Ventilation. Work with doors open and air moving, and follow the product’s warnings. Use a respirator rated for the vapors listed on the label if the manufacturer calls for it. Keep children, pets and anyone sensitive out of the area.
- Skin and eyes. Wear chemical-resistant gloves, eye protection and long sleeves. Epoxy can sensitize skin with repeated contact.
- Dust. Grinding concrete creates fine dust that can contain crystalline silica. Use a grinder with dust extraction, a vacuum rated for fine dust and a suitable respirator.
- Fire and fumes. Some solvents in coatings are flammable. In a garage, turn off pilot lights and gas appliance ignition sources such as water heaters, if the product label warns about flammable vapors, and do this only if you know how to do it safely. If you are unsure, have a qualified gas technician advise you. Keep ignition sources away.
- Old coatings and flooring. If the floor has old paint, tile adhesive or resilient flooring in an older building, do not grind or scrape it until you know what it contains. Some older products contain asbestos, and old paint can contain lead. Have it tested or consult a licensed professional.
Test the concrete for moisture
A simple check is to tape a square of clear plastic sheeting to the slab, seal the edges and leave it for around 24 hours. Moisture under the plastic or a darkened patch of concrete suggests moisture is moving through the slab. This is a rough screening test only. If you see signs of moisture, consider professional moisture testing, and address drainage or vapor problems before coating; for basement slabs, see water leaking through a foundation or basement. Cracks that open, grow or show displacement can point to bigger problems; see a structural professional if you notice them.
Surface preparation
Preparation determines most of the outcome.
- Clear and clean. Remove everything from the floor, sweep and vacuum.
- Degrease. Scrub oil stains with a concrete degreaser and rinse as directed. Let the slab dry fully.
- Repair. Fill cracks and spalls with a repair product that is compatible with your coating, then smooth once cured.
- Profile the surface. Mechanical grinding is commonly recommended for a strong bond. Some kits rely on acid etching instead, which gives a less consistent profile and requires careful safety precautions, rinsing and neutralising as the product directs.
- Vacuum thoroughly. Dust left behind affects adhesion.
Mixing and applying
- Check temperature requirements for the air and slab, and the working time.
- Mix Part A and Part B in the exact ratio specified, for the full recommended time, scraping the sides of the container.
- Pour the mix onto the floor promptly rather than leaving it in the bucket, where it can heat up and cure faster.
- Spread with a squeegee or roller and back-roll for an even finish, working in manageable sections and keeping a wet edge.
- Cut in edges first. Spiked shoes allow you to walk on wet product when scattering flakes or rolling.
For decorative pours, seal the perimeter so resin does not escape, mark out batch areas, and keep the room dry and at a steady temperature, as the product requires.
Flakes and topcoat
For flake floors, broadcast flakes into the wet base coat, allow it to cure as directed, then scrape lightly and vacuum off loose flakes. A clear topcoat, often urethane or a similar product recommended by the kit, seals the flakes and adds scratch and UV resistance. Use the products as a system whenever possible. If you are weighing a clear water-based coating instead, see water based polyurethane for concrete floors.
Curing and aftercare
Cure times vary by product. Many kits suggest keeping foot traffic off for around a day and waiting longer before vehicles, but check your kit. Early use is a common reason for marks. Clean with mild cleaners recommended by the manufacturer.
Choosing a kit
Compare:
- Whether it is a true epoxy or a water-based epoxy-type paint, as they differ in thickness and durability.
- Solids content and thickness of coat.
- Whether it includes prep materials, flakes and a topcoat.
- Coverage area per kit relative to your floor size, with a margin for waste.
- Manufacturer warranty terms and surface requirements.
Reviews and independent testing can help, but follow the instructions closely whatever you choose.
How much does it cost?
Costs vary by region, kit quality and floor size. DIY kits generally cost much less than professional installation, but equipment such as a rented grinder and dust control add to the budget. Get quotes from local contractors and price out kits and tool rental for your actual square footage to compare.
Can you make your own epoxy resin?
In practice, no. Epoxy depends on carefully formulated resin and hardener that react in a controlled way, and homemade mixes are unsafe and unreliable. Buy a commercial two-part system made for floors.
Common mistakes
- Coating damp concrete.
- Skipping surface profiling.
- Mixing by eye or using the wrong ratio.
- Working outside the temperature range.
- Applying too thin or too thick against the instructions.
- Allowing early traffic.
For other floor-related repair topics in this cluster, see how to repair water damaged floorboards and the guide to DIY pour in place rubber surfacing, another poured surface for garages and outdoor areas.