Epoxy Garage Floor: Roller Coat or Self-Levelling Layer
Short answer: for a 6 × 3.5 m garage (21 m²) a roller-applied system – primer, two coats of epoxy and two coats of topcoat – needs 6.83 kg of primer, 11.55 kg of epoxy and 3.99 kg of topcoat, or 30 kg in packs (10 + 16 + 4 × 1 kg). A 2 mm self-levelling layer on the same area needs 35.7 kg of epoxy plus another 35.7 kg of quartz sand, so you buy 95.7 kg of material for the whole system. The epoxy calculator works out both systems and picks the packs.
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Two ways to finish a garage floor
A roller coat is a thin film: primer and one or two coats of epoxy paint. It is quick to apply, stops concrete from dusting, resists oil and is easy to clean. Self-levelling epoxy is poured in a layer a few millimetres thick with quartz sand, evens out small irregularities and takes heavier loads, but needs more material and a flatter substrate.
| Roller coat (system 3) | Self-levelling 2 mm (system 7) | |
|---|---|---|
| Primer | 6.83 kg | 6.83 kg |
| Epoxy | 11.55 kg (2 coats of 275 g/m²) | 35.7 kg (0.85 kg/m² per mm) |
| Quartz sand | – | 35.7 kg (ratio 1:1) |
| Topcoat | 3.99 kg (2 coats of 95 g/m²) | 3.99 kg |
| To buy | 30 kg | 95.7 kg |
How to use the epoxy calculator – step by step
- 1. Enter the floor area (6 × 3.5 = 21 m²).
- 2. Choose the system: 3 for a roller coat or 7 for a self-levelling layer.
- 3. Choose the primer consumption (e.g. 325 g/m²) according to the product's technical data sheet.
- 4. For a roller coat choose the epoxy consumption per coat and the number of coats; for self-levelling, the thickness in mm.
- 5. Choose the topcoat consumption and number of coats.
- 6. The result shows kilograms per material and the pack combination with the least surplus.
Why you buy more than you use
Epoxy is sold in kits (resin and hardener) of fixed weight. For 6.83 kg of primer you buy a 10 kg pack, for 11.55 kg of epoxy a 16 kg pack, and for 3.99 kg of topcoat four 1 kg packs. The calculator picks the combination with the lowest total weight that covers the need; for the 35.7 kg self-levelling layer that is 30 + 16 kg.
Do not mix the surplus in advance: mixed epoxy has a limited working time, so mix only as much as you can apply.
Preparing the substrate
- The concrete must be sound, dry and clean, without oil, laitance or flaking old coatings – the product's technical data sheet sets the conditions and the preparation method.
- Repair cracks and holes before priming; a self-levelling layer does not replace levelling larger unevenness.
- Primer goes on in one or two coats depending on how absorbent the concrete is – that is why manufacturers give a consumption range rather than a single value.
- Before the whole garage, do a test area and measure the actual consumption.
Most common mistakes
- Forgetting that a second coat of epoxy and topcoat doubles the quantity.
- Leaving out the 1:1 quartz sand in a self-levelling layer – it is half the weight of the layer.
- Entering a consumption outside the range in the product's technical data sheet.
- Garage area without the ramp, threshold or step that are also coated.
- Ignoring pot life and application temperature – a cold garage slows curing.
Sources and assumptions
The technical data sheet of an epoxy coating gives 0.30–0.50 kg/m² of primer and 0.25–0.3 kg/m² per roller coat; the description of a self-levelling system gives 1.6–1.9 kg/m² per mm with quartz sand up to a 1:1 ratio and a thickness of 1.5–3 mm. The calculator uses 0.85 kg/m² of epoxy per mm and the same amount of quartz (1.7 kg/m² per mm in total), which is within that range. Topcoat consumption (95 g/m²) and pack sizes (primer 30 and 10 kg, epoxy 30 and 16 kg, topcoat 5 and 1 kg) are calculator defaults – check them for your product. These are typical values – the data on the pack or technical data sheet of the product you buy applies.
Frequently asked questions
How much epoxy do I need for a 6 × 3.5 m garage?
For a roller coat in two coats of 275 g/m² you need 11.55 kg of epoxy, plus 6.83 kg of primer and 3.99 kg of topcoat – 30 kg in packs in total.
Is a roller coat enough for a garage?
For a car and a flat, sound substrate a roller coat is a common choice. A 2 mm self-levelling layer is thicker and tougher but needs more than three times as much material.
How heavy is the material for a 2 mm layer on 21 m²?
The calculator counts 35.7 kg of epoxy and 35.7 kg of quartz sand (ratio 1:1); with primer and topcoat that is 95.7 kg to buy.
Does an epoxy garage floor need a topcoat?
The topcoat protects the surface and makes cleaning easier. For 21 m² in two coats of 95 g/m² you need 3.99 kg, i.e. four 1 kg packs.
Calculate yours: Epoxy floor calculator