Polyurethane cement (PU cement) floors for food and chemical plants

What is a polyurethane cement floor?

A polyurethane cement (PU cement) floor is a hybrid system: liquid polyurethane components are mixed with a powder of cement, mineral fillers and pigments. On curing, the polymer matrix and the cement hydration products form a dense, very strong and resistant layer several millimetres thick. Such floors are designed for conditions in which epoxy coatings do not last long: hot spills, washing with hot water and steam, sharp temperature changes, fats and organic acids, impact and heavy trolleys.

The main field of application is the food industry: dairies and meat processing plants, breweries and beverage production, bakeries, confectionery workshops and professional kitchens. PU cement is also laid in chemical and pharmaceutical plants, washdown areas, cold rooms and freezer rooms, provided the operating temperatures fall within the range given in the data sheet of the specific system.

Types by laying method

Self-levelling coatings

Flowable compounds with a smoother surface that is easier to clean. Suitable for areas with medium loads and moderate thermal exposure; slip resistance is achieved by broadcasting aggregate.

Trowelled screeds

Stiff mortars laid and trowelled by hand or machine in a thicker layer. This is the choice for heavy loads, impact, hot spills and steam; the surface is textured and slip-resistant.

Compounds for coving and vertical surfaces

Thixotropic mortars that do not slump on a wall. They are used to form rounded junctions between the floor and walls, columns and equipment plinths — without coving, a seamless food-grade floor loses its point.

Topcoats

Thin seal coats over PU cement change the texture, make cleaning easier and give an even colour; some systems also offer versions with conductive properties.

Why PU cement is chosen for food production

• Thermal shock and hot washdown. The temperature limits and the permissible temperature difference depend on the layer thickness — they are taken from the data sheet of the specific system.
• Organic acids and fats. Lactic, acetic and citric acids, sugars, vegetable and animal fats, cleaning agents and disinfectants — manufacturers publish resistance lists.
• Seamless finish and coving. There are no tile joints where dirt and bacteria collect, and junctions with walls are rounded.
• Slip resistance in wet areas. The texture is chosen to suit the cleaning regime: the rougher the surface, the safer it is and the harder it is to clean.
• Mechanical strength. The coating withstands the trolleys, dropped containers and impacts typical of processing halls.

Falls to drains and channels are specified in the Uzbek code ShNK 2.03.13-24 “Floors”: in rooms with medium and high exposure to liquids, 0.5–1 % for seamless finishes. The code treats as medium the exposure in which the floor is periodically wetted and liquid runs over the surface from time to time, and as high the exposure in which liquid flows constantly or frequently.

How to choose a system

Temperature regime

First, the range of operating temperatures is established: freezer rooms, hot spills, steam cleaning, the temperature and volume of hot effluent. The higher the temperature and the more frequent the thermal shocks from cold and hot water, the thicker the system must be — the manufacturer gives the relationship between thicknesses and temperatures in the data sheet. For the materials in the catalogue, layers 3–6 mm thick are designed for temperatures up to +60…+80 °C, while trowelled layers 9–12 mm thick are designed for up to +120…+130 °C, with short-term spills up to +150 °C, and for cold down to −40 °C.

Chemicals

A list of media is drawn up: the product, cleaning agents and disinfectants, their concentrations, temperature and duration of contact. Resistance to the specific medium is confirmed by our questionnaire: substance, concentration, temperature and regime.

Loads

Foot traffic and hand trolleys — a self-levelling coating; forklifts, impact, metal wheels — a thicker trowelled screed.

Substrate and schedule

PU cement has its own requirements for the strength, age and moisture content of the concrete — they are set by the technical data sheet. At operating plants, the schedule matters: the time to foot traffic and to return to service differs between systems — compare them using the data sheets at the actual temperature in the hall.

Details without which PU cement does not work

• Anchor grooves. Along free edges and at walls, drains, channels and movement joints, grooves are cut into the concrete and filled with the material, so that the edges do not lift with temperature changes. For the materials in the catalogue, the grooves are made twice the coating thickness in width and depth; the exact dimensions and spacing are given in the manufacturer’s data sheet.
• Movement joints in the substrate are carried through the coating and sealed with a sealant of suitable chemical resistance.
• Drains and channels are made of stainless steel, with flanges for the coating to terminate against; the falls to them are formed in the substrate or the screed.
• Coving is formed from a special mortar of the same system before the floor is laid.
• A trial area on site helps agree the texture and colour before the whole area is laid.

How PU cement is laid

• The components are conditioned in advance at the temperature specified in the data sheet: flow, working time and colour depend on it.
• Complete kits are mixed in a forced-action mixer in the order specified by the manufacturer; water or solvent must not be added.
• The working time of the mix is short, so the floor is laid by a team in bays, without stopping in the middle of a bay.
• Self-levelling compounds are spread with a gauge rake or a squeegee set to the specified gap; trowelled grades are laid to screed rails and compacted with a hand or power trowel.
• The fresh layer is protected from water, dust and draughts for the periods given in the data sheet, and before food production starts, the floor is washed as recommended by the manufacturer.

Common mistakes

• An epoxy floor instead of PU cement in a hot washdown area — cracking and delamination within the first few months.
• No anchor grooves along the edges and at drains — the edges lift.
• A system thinner than the data sheet specifies for the actual temperature of the spills.
• Laying without coving and with reverse falls — standing water and dirt along the walls.
• Too smooth a texture in a wet area — a slippery floor; too rough a texture in a dry area — difficult cleaning.
• Failure to observe the component temperature and mixing time — uneven colour and surface defects.

See also: resin flooring — overview, epoxy floors, chemical protection.

Materials in the catalogue

• Sikafloor-20 PurCem — Sika — trowel-applied polyurethane-cement wearing screed, 6–9 mm, for food and chemical plants.
• Sikafloor-21 PurCem — Sika — self-levelling polyurethane-cement floor screed, 3–6 mm, smooth matt finish.
• Sika Ucrete MF — Sika — smooth heavy-duty polyurethane-cement screed, 4–6 mm, for dry process areas.
• Sika Ucrete UD 200 — Sika — slip-resistant polyurethane-cement screed, 6–12 mm, steam-cleanable, for wet process areas.
• Jotafloor PU Crete — Jotun — antimicrobial hybrid polyurethane floor, 4–6 mm, for food and pharmaceutical plants.
• Fosroc Nitoflor SL3000 UT — Fosroc — 3–6 mm flow-applied polyurethane concrete floor for food and pharmaceutical plants.
• Mapefloor CPU+/HD — Mapei — 6–12 mm polyurethane-cement screed for food and chemical plants, thermal shock to +150 °C.

This list is not exhaustive. The final choice is made on the basis of the manufacturer’s documents and the project requirements.

Frequently asked questions

Why is PU cement more expensive than an epoxy floor?

The system is thicker, more complex to lay and designed for conditions in which epoxy would have to be replaced. What should be compared is the cost of the floor over its service life, including production shutdowns for repairs.

Can PU cement be made smooth and coloured?

Self-levelling versions and topcoats give a smoother surface, but the colour range of PU cement is usually narrower, and the shade may change over time and when heated. If appearance matters, agree on it using a trial area.

Is PU cement suitable for freezer rooms?

Yes, if the system’s minimum service temperature according to the data sheet is below the room temperature. For rooms with defrost and washdown cycles, such systems are the first to be considered.

We will select a polyurethane cement system to suit the temperature, chemicals and loads in your production hall — call us or message us on WhatsApp/Telegram: +998 94 094 52 27.