The right product here depends on your site. We confirm it before naming it.
Step-by-step solution
Polyurethane & elastic floors
Polyurethane floors are tougher and more flexible than epoxy, can bridge fine cracks and, with the right seal coat, resist UV. Use them on crack-prone slabs, for comfortable decorative interiors, on balconies, and as PU-cement screeds where heavy wear and heat occur.
- 7 steps
- 7 products
- 4 answers
You need this when…
- Fine shrinkage cracks showing through an old epoxy floor
- Floor should feel softer and quieter underfoot (schools, hospitals, offices)
- Balcony or terrace coating cracking and fading in the sun
- Heavy impact and hot washdown in a processing area
The work, step by step
General guidance based on the manufacturer data sheets. Site conditions differ: confirm the system with MCT before you start. Where we do not name a product, ask us and we will confirm the right one.
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Step 1: Test and prepare the slab
The slab needs at least 25 N/mm² compressive and 1.5 N/mm² pull-off strength (Sikafloor-330 p.4), moisture ≤4 % and no rising moisture (Sikafloor-330 p.3; Sikafloor-3240 p.3). Prepare mechanically to remove laitance (Sikafloor-330 p.4).
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Step 2: Prime
Prime with an epoxy primer such as Sikafloor-161; the UV-stable deck systems use it lightly broadcast (Sikafloor-359 SG p.2).
Product for this stepAsk us -
Step 3: Industrial crack-bridging floor
Sikafloor-3240 is a tough-elastic, crack-bridging PU wearing course for production and storage areas, and is also broadcast for wet areas and car decks (p.1). It is not for surfaces with a slope over 1 % (p.3).
Sikafloor-3240 Sika Professionals only Smooth wearing course with crack-bridging properties for industrial floors in production and storage facilities, workshops etc. (TDS p.1)
- Temperature stated in TDS
- +10 °C min. / +30 °C max (TDS p.2)
- Pack
- 4.75 kg containers Part A
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Step 4: Comfortable, quiet interiors
Sikafloor-330 is an elastic, self-smoothing decorative PU for hospitals, schools, offices and homes, interior only (p.1); apply at +15 °C to +30 °C (p.3). Finish with the Sikafloor-305 W matt seal coat (p.1).
Sikafloor-330 Sika Professionals only Request a quotation Decorative elastic smooth resin flooring wearing layer for: Sika ComfortFloor® and Sika ComfortFloor® Pro Systems, Hospitals, Schools, Retail areas, Showrooms, Entrance halls. (TDS p.1)
- Temperature stated in TDS
- +15 °C min. / +30 °C max (TDS p.3)
Sikafloor-305 W Sika Professionals only Request a quotation Matt seal coat for Sika ComfortFloor® flooring range, for smooth Sikafloor® polyurethanes and for the Sikafloor® Multidur epoxy range. (TDS p.1)
- Temperature stated in TDS
- +10 °C min. / +30 °C max (TDS p.2)
- Pack
- 1,5 kg containers Part A
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Step 5: Balconies, terraces and stairways
Sikafloor-400 N Elastic is a UV-resistant, waterproof, crack-bridging coating for balconies, terraces, footbridges and stairways with light to medium wear (p.1).
Sikafloor-400 N Elastic Sika Professionals only Request a quotation Sikafloor®-400 N Elastic is used as: Smooth or slip resistant, UV resistant, waterproof, crack-bridging coating for concrete and cementitious screed substrates, For light to medium mechanical exposure, For balconies, terraces, footbridges, stairways etc, As the top coat in the Sika Ground Water P… (TDS p.1)
- Temperature stated in TDS
- +10 °C min. / +30 °C max (TDS p.2)
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Step 6: Heavy-duty PU-cement screeds
Sikafloor-21 PurCem and Sikafloor-24 PurCem are self-smoothing PU hybrid screeds with high abrasion, chemical and impact resistance (p.1). They tolerate higher substrate moisture if there is no ponding water (Sikafloor-21 PurCem p.3). Cut retaining grooves twice the floor thickness at all free edges (p.4).
Sikafloor-21 PurCem Sika Professionals only The Product is used as a scratch coat or wearing coat layer in Sikafloor® PurCem® flooring systems. Please note: The Product may only be used by experienced professionals. (TDS p.1)
Sikafloor-24 PurCem Sika Professionals only The Product is used as a scratch coat or wearing coat layer in Sikafloor® PurCem® flooring systems. Please note: The Product may only be used by experienced professionals. (TDS p.1)
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Step 7: UV-resistant seal coat
Sikafloor-359 SG is a UV-resistant, non-yellowing PU seal coat for broadcast systems on car-park decks, ramps and warehouses (p.1).
Sikafloor-359 SG Sika Professionals only Request a quotation Abrasion resistant seal coat with high mechanical resistance for broadcast systems with crack-bridging properties in industrial flooring Particularly suitable for car park decks, ramps and warehouses etc. (TDS p.1)
- Temperature stated in TDS
- +10 °C min. / +35 °C max (TDS p.3)
- Pack
- Part A: 16.5 kg containers
Proposal brief
Polyurethane & elastic floors: scope and system
A starting point for a site proposal. Quantities, prices and the final specification follow a site visit or photos.
Scope of work
- Slab testing and mechanical preparation
- Crack and joint pre-treatment
- Primer and PU wearing layer or PU-cement screed
- Seal coat (matt or UV-resistant)
- Joint sealing and edge details
System build-up
| Step | Product | Pack | Source |
|---|---|---|---|
| 3. Industrial crack-bridging floor | Sikafloor-3240 (professionals) | 4.75 kg containers Part A | TDS p.1 · October 2023, Version 02.02 |
| 4. Comfortable, quiet interiors | Sikafloor-330 (professionals) | — | TDS p.1 · May 2021, Version 04.01 |
| 4. Comfortable, quiet interiors | Sikafloor-305 W (professionals) | 1,5 kg containers Part A | TDS p.1 · December 2022, Version 03.02 |
| 5. Balconies, terraces and stairways | Sikafloor-400 N Elastic (professionals) | — | TDS p.1 · May 2021, Version 02.01 |
| 6. Heavy-duty PU-cement screeds | Sikafloor-21 PurCem (professionals) | — | TDS p.1 · December 2022, Version 05.01 |
| 6. Heavy-duty PU-cement screeds | Sikafloor-24 PurCem (professionals) | — | TDS p.1 · December 2022, Version 03.01 |
| 7. UV-resistant seal coat | Sikafloor-359 SG (professionals) | Part A: 16.5 kg containers | TDS p.1 · May 2021, Version 02.01 |
What we need from you
- Area (m²), indoor or outdoor
- Use: traffic, impact, chemicals, hot water, comfort
- Photos of existing cracks or coatings
- Moisture history of the slab
- Preferred colour and finish
Site conditions
- Substrate at least 25 N/mm² and 1.5 N/mm² pull-off (Sikafloor-330 p.4)
- Interior systems applied at +15 °C to +30 °C (Sikafloor-330 p.3)
Not included
- Structural slab repairs
- Furniture and equipment removal
Questions customers ask
Should I choose PU or epoxy?
Choose PU where cracks, impact or sunlight are a concern: Sikafloor-3240 is crack-bridging and tough-elastic (p.1) and Sikafloor-359 SG is UV resistant and non-yellowing (p.1). Epoxy suits stable indoor slabs (Sikafloor-263 SL p.1).
Can PurCem go on a damp slab?
Yes, if there is no ponding water and no rising moisture; the surface must look dry and have at least 1.5 N/mm² pull-off (Sikafloor-21 PurCem p.3).
When can we walk on Sikafloor-3240?
After about 12 hours at +20 °C, with light traffic after about 2 days (Sikafloor-3240 p.3).
Can I use Sikafloor-330 on a veranda?
No. It is for interior use only (Sikafloor-330 p.1). For balconies and terraces use Sikafloor-400 N Elastic (p.1).
Steps and product facts are taken from the manufacturer data sheets (page cited). Products are named only where the data sheet confirms the use; quantities follow a site visit or photos. General guidance: check the data sheet or ask us before you start.