Resin flooring FAQ
Resin flooring questions, answered.
Coverage, primers, damp concrete, cure times and choosing a system: answers for contractors and specifiers, taken from Jofa's own product data.
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at 20 °C
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What do you need to know?
Planning and quantities
How much will the job need?
How do I work out how much material a job needs?
Multiply the area by the product's consumption rate. Coatings are given per coat: HB-300 uses 0.25–0.30 kg/m² per coat. Screeds are given per millimetre of thickness: JofaCrete RS uses about 2.1 kg/m² per mm, so a 6 mm floor needs about 12.6 kg/m².
The coverage calculator does the sums for you, rounds up to whole kits and can add 10% for waste. All coverage figures are theoretical: rough or porous concrete uses more.
How much primer will I need?
Most Jofa epoxy primers use 0.25–0.30 kg/m² per coat, depending on how porous and rough the concrete is. OT-235 can use up to 0.50 kg/m², and on very porous concrete SRS-700 can use 0.6–1.0 kg/m². JofaCrete Primer, for the polyurethane cement systems, uses about 0.28 kg/m² at 200 microns.
How thick should the floor be?
It depends on the system and how the floor is used. Typical thicknesses from Jofa's product pages and datasheets:
- Epoxy coatings such as HB-300: thin coats of 0.25–0.30 kg/m² each
- Epoxy self-smoothing: about 2–3 mm (EPSL-3000)
- Epoxy quartz screed: 4–6 mm (EPQ-100)
- Polyurethane cement self-smoothing: about 3 mm (JofaCrete SL-3) or 5 mm (JofaCrete SL-5)
- Polyurethane cement screeds: 5–7 mm (JofaCrete MT), 6–9 mm (JofaCrete HF and RS)
- Falls, ramps and bulk repairs: 6–60 mm (JofaCrete Bulk)
Concrete and primers
Getting the base right.
What does the concrete need to be like before resin goes down?
Jofa's datasheets ask for concrete with a compressive strength of at least 25 N/mm² and a tensile (pull-off) strength above 1.5 N/mm². It must be clean and sound, with laitance and contamination removed. For most epoxy systems it must also be dry: no more than 75% RH, measured to BS 8203, unless a moisture tolerant primer is used.
During application the concrete should be at least 3 °C above the dew point, and for most epoxy products the air should stay below 75% RH while the floor goes down and for the first 48 hours.
Can I lay resin on damp concrete?
Yes, with the right primer. DPM-230 Moisture Tolerant Epoxy Primer can go on concrete up to 98% RH (BS 8203): one coat up to 85% RH, two coats from 85% to 93%, and up to three coats up to 98%. DPM-250 is a flexible damp proof membrane for up to 98% RH that controls residual moisture and rising damp.
The JofaCrete polyurethane cement systems tolerate concrete up to 90% RH, as long as there is no rising damp or groundwater pressure.
Which primer should I use?
- EPR-100: general purpose, on dry concrete (below 75% RH)
- DPM-230: on damp concrete, up to 98% RH
- OT-235: on oil-contaminated concrete, after cleaning and preparation
- SRS-700: an ultra-low viscosity primer for porous concrete
- EPT-115: a tack coat, overcoated after 1–2 hours
- Bondex-421: a water-based epoxy bonding primer with a long pot life
- JofaCrete Primer: for JofaCrete polyurethane cement systems
- WB-120 ESD: the conductive primer for ESD floors
If you are not sure, tell us about the floor and our technical team will recommend one.
Choosing a system
The right floor for the job.
Should I specify epoxy or polyurethane cement?
Polyurethane cement (JofaCrete) is the choice for wet, hot and heavily cleaned areas. JofaCrete HF withstands thermal shock and steam cleaning and tolerates -40 °C to 120 °C, and JofaCrete RS and MT are also suitable for steam cleaning.
Epoxy coatings, self-smoothers and quartz screeds give a seamless, chemical resistant and easily cleaned finish for warehouses, workshops, retail, healthcare and dry or wet process areas. The system guides set out the full build-up for each.
Which floors suit food and drink production?
The JofaCrete polyurethane cement range is made for it. JofaCrete HF, SL-3, SL-5 and CG coving include an antimicrobial additive tested to ISO 22196:2011. See flooring for food and drink production.
Can the floor be steam cleaned?
JofaCrete HF, RS and MT are suitable for steam cleaning. JofaCrete HF, RS and RG are rated from -40 °C to 120 °C (RS and RG when laid at 9 mm), and JofaCrete SL-3 and SL-5 are resistant to hot water.
Do you make slip-resistant floors?
Yes. HB-300, HB-320, HB-340 and EPS-210 have slip resistant options; on HB-300, aggregate is added to the first coat. EPQ-100 epoxy quartz screed gives a slip resistant finish for wet or dry areas, and JofaCrete MT is designed for an aggregate scatter. If a project needs a particular slip rating, tell us when you request a specification.
Do you have an anti-static (ESD) floor?
Yes. EPSL-3000 ESD is an electrostatic dissipative epoxy self-smoothing floor, laid over WB-120 ESD conductive primer, for areas that must meet EN 61340-5-1.
What do you use for coving?
JofaCrete CG (polyurethane cement) and EPC-50 (epoxy) form seamless wall-to-floor junctions. Allow about 3 kg per linear metre of coving 150 mm high with a 50 mm base at 5 mm thick.
Are there low odour products for occupied buildings?
Most Jofa resins are solvent free and low odour, and EPR-100, OT-235 and Bondex-421 are described as suitable for occupied areas. The PolyEco topcoats and Jofa-Aqua-145 are water-based and low VOC.
Curing
Getting the floor back into use.
How long before the floor can be used?
At 20 °C, Jofa's datasheets give, for example:
- JofaCrete polyurethane cement screeds and self-smoothers (RS, MT, SL-3, SL-5): light traffic after 24 hours, full traffic after 48 hours, full chemical cure after 7 days
- JofaCrete Bulk: light traffic after 12 hours, full traffic after 48 hours
- EPSL-3200, EPG-250 and EPC-50 epoxy: foot traffic after 24 hours, light traffic after 48 hours, full cure after 7 days
- Jofa-Aqua-145: foot traffic after 8 hours, light traffic after 48 hours, full cure after 7 days
Colder conditions slow curing down, so check the datasheet for the product and the site temperature.
How long do I leave between coats?
HB-300, HB-320, HB-340, PA-100-LV and the FlexiCoat and ErgoFlexi polyurethanes should be overcoated within 16–24 hours at 20 °C. FlexiCoat and ErgoFlexi need a light abrade if that window is missed. Primers are quicker: EPT-115 after 1–2 hours, OT-235 after 4–6 hours once tack free, and WB-120 ESD after 6–8 hours.
What temperature and humidity does the site need?
Most Jofa products are laid and cured between 10 °C and 30 °C, with the concrete at least 3 °C above the dew point. Most epoxy products need the air below 75% RH during application and for the first 48 hours. DPM-230 can go down at up to 85% RH, and Jofa-Aqua-145 ideally below 80%. Decorative terrazzo (ETZ-321 and ETX-180) and EPSL-3000 need 15 °C to 30 °C.
Help and documents
Datasheets, specifications and installers.
Where do I find datasheets?
Every product datasheet and system guide is in the datasheet library, free to download. Each product page also has its own datasheet.
Can you help with a specification?
Yes. Tell us about the area, the conditions and your timescale, and our technical team will recommend the right system and send the datasheets.
Do you lay floors?
No. Jofa Resins manufactures resin flooring systems and does not lay floors itself. Find an installer and we will put you in touch with one near you.
Still have a question? Ask our technical team.
Tell us about the floor, the conditions and your timescale, and we will recommend the right system.
Request a specification