Epoxy Floor Installation Steps, With the Waiting Times From the Data Sheets

Epoxy work looks simple from the outside: mix two components and spread them on the floor. But most of what decides the life of the floor happens before the tins are opened, and what happens afterwards is governed by hours and minutes set by the product's technical data sheet, not by the installer's mood.

Here we set out the installation steps as they should be carried out, using the figures published in the Sikafloor-264 (roller system) and Sikafloor-263 SL (self-levelling system) data sheets as two documented examples. Every other product has its own numbers, and the rule is constant: the data sheet is the reference.

What is checked before epoxy floor installation begins?

Before any grinding, the concrete and the weather are judged. Both data sheets require concrete moisture below 4% by weight and a surface tensile strength of at least 1.5 N/mm². ASTM D4263 sets out a plastic sheet test as an indicator of capillary moisture in concrete that could harm coatings that do not tolerate moisture; it is a preliminary check and does not replace measurement with an instrument.

How is the concrete prepared before epoxy installation?

Epoxy bonds to the surface, not to the sound concrete beneath, so if there is weak cement laitance, old paint or oil on the surface, it will come away with it. All of that is therefore removed mechanically. The concrete surface profile guide based on ICRI's method shows that thin coatings need a low profile (CSP 1 to 2), high-build coatings CSP 2 to 3, and self-levelling systems CSP 3 to 6, and that mechanical abrasion is the first and safest option.

1. 1

   Clear the space and protect surroundings

   Remove furniture, protect the bottom of walls and doors, and close the space to traffic for the whole duration of the work.

2. 2

   Grinding or shot blasting

   Diamond grinding or shot blasting to the profile the system requires, with dust extraction during the work.

3. 3

   Repair

   Fill stable cracks and holes with epoxy putty or mortar, and treat expansion joints so that they keep their ability to move.

4. 4

   Final vacuuming

   A thorough industrial vacuum, because fine dust left behind forms a separating layer between the concrete and the primer.

Details of repair materials and which suit each defect are in the guide to epoxy putty.

Primer and mixing: where do the minutes go?

The primer soaks into the pores of the concrete, seals them and forms the bridge between the concrete and the coats that follow. Euclid Chemical recommends applying coatings while the concrete temperature is falling, not rising, because rising temperature pushes air out of the pores and creates bubbles and pinholes. In practice that means starting in the late afternoon or evening.

Once the two components are mixed, a countdown begins. The Sikafloor-264 data sheet gives a pot life of about 45 minutes at 10°C, 20 minutes at 20°C and 12 minutes at 30°C. For Sikafloor-263 SL it is about 60, 30 and 15 minutes respectively. Mixed material left in the bucket heats up and hardens faster, so it is spread on the floor as soon as it is mixed.

Applying the main coats and the recoat window

For the roller system, the Sikafloor-264 data sheet gives consumption of about 0.25 to 0.3 kg/m² per coat, normally two coats. For the thicker self-flowing layer of the same product it is about 0.9 to 1.2 kg/m². Sikafloor-263 SL is applied at a thickness between 1 and 6 mm, with consumption of about 1.6 to 2.0 kg/m² per millimetre depending on the filler ratio. In usual practice the self-levelling layer is spread with a notched trowel, then a spiked roller is passed over it to release trapped air.

Between coats there is a time window with a minimum and a maximum. Before the minimum the coat is still soft, and after the maximum it becomes hard and smooth so the next coat will not bond to it without abrading it first.

If the air is humid or the temperature falls at night, a waxy, greasy film called "amine blush" may form on the surface. Carboline explains that it results from moisture and carbon dioxide reacting with the epoxy hardener, that it may be invisible or show as a colour change, and that it must be washed off and removed before any later coat or bonding suffers. This is common in coastal cities such as Jeddah and Dammam.

Anti-slip and the top coat

On ramps and washing areas, quartz sand is broadcast onto the coat while it is wet and then sealed with a top coat, and both data sheets state that a slip-resistant surface can be obtained. In spaces that receive sunlight, a UV-resistant top coat is preferred, because both data sheets note that direct sunlight may change the colour of epoxy without affecting its performance.

When can you walk on the floor and use it fully?

During these days ventilation stays on, and washing the floor, placing heavy furniture or dragging anything across it is not allowed. Details on smell and when occupants can return are in epoxy odour and occupant safety, and general safety guidance is on the health and safety page.

Common epoxy shortcuts that ruin the result

• Acid-washing the floor instead of grinding it, to save time.
• Skipping the moisture test on ground floors because the floor "looks dry".
• Applying at midday in an unconditioned space, exceeding the temperature limit in the data sheet.
• Passing the maximum recoat window without abrading the previous coat.
• Opening the space to use after one day because the surface is "dry" to the touch.

Each of these shortcuts has a known effect, and you can see how to read their traces in causes of epoxy floor peeling. For the material's general properties see the epoxy guide. If you want an installation that documents each step from testing to handover, request an inspection through Azl's epoxy flooring service.