Protecting concrete against acids in dairies and breweries

In a dairy or a brewery, bare concrete dissolves under lactic acid, fermenting sugars and acid cleaners, and hot washdown water makes the attack worse through thermal shock. Lasting protection combines a resin system chosen for the actual chemicals and temperatures (often urethane cement, sometimes vinyl ester or novolac epoxy), slopes toward sealed drains, a cove base, and joints treated with the same care as the floor itself.

Dairy production rooms, cheese plants, breweries and beverage plants share the same enemy: concrete permanently exposed to acidic moisture and hot washdown. Floors age quickly there when the system was not chosen for those conditions. This guide complements our article on food processing plant flooring, which covers hygiene, slopes and slip resistance; here the focus is on the chemical and thermal resistance of the concrete.

Why do acids attack concrete?

Acids attack concrete because they react with the cement paste, which is alkaline, and turn it into soluble salts that washdown water carries away. The aggregate loosens, the surface roughens, then the slab loses thickness.

In these plants, the attack comes from several sources:

• Lactic acid from milk, whey and fermented products, which sits in cracks and around equipment.
• Sugars and wort that ferment on the concrete and produce organic acids.
• Acid cleaners (nitric or phosphoric acid, for example) used in alternation with caustic cleaners in clean-in-place cycles.
• Oxidizing sanitizers, which degrade some resins.

The attack is slow at first, then speeds up as the surface becomes porous and holds liquids. That is why concrete is often seen disappearing around drains, under tank outlets and along walls.

What role do hot water and thermal shock play?

Hot water speeds up chemical reactions and, above all, causes thermal shock when a cold floor receives a very hot discharge or washdown. Rigid resins and concrete do not expand the same way: the coating can crack or debond.

The most exposed points are pasteurizer discharges, tank drains, keg and barrel washing areas and the areas around drains. Our urethane cement vs epoxy comparison explains why urethane cement handles these cycles better than a standard epoxy. The maximum temperature and how often hot discharges occur are part of the data to provide before any choice.

Which systems protect concrete in these plants?

The system is chosen from three inputs: the actual chemicals (type and concentration), the maximum temperature and its frequency, and traffic. No system is best everywhere: several systems are often combined in the same plant.

The choice between vinyl ester and novolac epoxy is detailed in our article on vinyl ester vs novolac epoxy. Manufacturers' chemical resistance charts remain the reference for each product and each concentration.

Why do joints and drains decide how long the floor lasts?

Joints and drains are the weak points because that is where liquids collect, movement concentrates and the coating ends. An excellent floor with a poorly treated joint deteriorates from underneath.

• Expansion and construction joints. They must stay movable: they are rebuilt with a flexible sealant resistant to cleaning chemicals, in a joint with reinforced edges.
• Saw-cut contraction joints. Depending on the system, they are filled and coated over, or carried through the coating with a suitable sealant.
• Drains and trenches. The coating must be mechanically tied into the drain, with continuous anchoring and sealing; a poorly connected stainless steel drain lets acid under the floor.
• Cove base. It eliminates the wall-floor corner where acid sits and bacteria lodge.
• Equipment plinths. Anchors and tank bases are treated with the same system, or acid enters through the fastener holes.

Containment for cleaning chemicals follows the rules in our article on concrete secondary containment coating.

How do you prepare concrete that is already attacked?

Attacked concrete is prepared by removing all of the contaminated, weakened layer down to sound concrete, then neutralizing and washing to remove acid residue and fats. A coating applied over concrete still soaked with acid or fat will debond.

1. Remove deteriorated concrete by shot blasting, scarifying or hydro blasting, depending on depth.
2. Degrease areas soaked with milk fat or beer residue, with a suitable cleaner and thorough rinsing.
3. Check that the exposed concrete is sound and clean, and measure its moisture: our article on concrete moisture describes the tests.
4. Reprofile with a mortar compatible with the system, rebuilding slopes toward drains.
5. Achieve the CSP profile required by the manufacturer, per our article on concrete surface preparation.

In these plants, concrete is often permanently damp: that is one of the reasons urethane cement is so common there.

Where the slab has lost a lot of thickness, the reprofiling layer also restores the falls to drains. Getting those slopes right at this stage matters: a coating follows the surface beneath it, so standing water left by a flat or reversed slope will keep attacking the new floor at exactly the same spots as before. Slopes are checked with a straightedge or a flood test before the system is applied.

How can the work be done without stopping production?

The work is organized by zone and by shutdown window, choosing systems whose cure fits the available window. Odours, room temperature and food contact are managed with the plant's quality team.

• Isolate each zone with temporary partitions and ventilation, to protect products and personnel.
• Schedule the return to service according to the cure and recoat times on the data sheets.
• Plan acceptance tests (adhesion, continuity, thickness) before the return to service.

We work only in industrial settings, including Montérégie and Ontario.

How do you get a quote?

Send the list of chemicals and cleaners used (with concentration and temperature), photos of the floor, the affected areas, slopes and drains, and the possible shutdown windows. Our industrial epoxy flooring page presents the floor systems, our concrete protection page the solutions by structure, and our protective coatings page all our systems. Our crews and qualified subcontractors carry out the work.

Pricing on consultation: fill in the request a quote form, reply within 24 business hours.

Frequently asked questions

Is a standard epoxy enough in a dairy?

It suits dry areas and corridors, but it resists hot washdown, thermal shock and standing lactic acid less well. In production rooms, urethane cement or a more acid-resistant system is generally preferable.

Why does concrete disappear around drains?

Because acid and hot water concentrate and sit there, often with a drain-to-floor connection that is not sealed. The concrete is attacked from above and below at the same time.

Does the whole floor have to be redone at once?

No. Work can proceed by zone, depending on concrete condition and shutdown windows, provided the transitions between zones and old coatings are properly detailed.

How do we know which system resists our cleaners?

The exact list of products, their concentration and their temperature are compared with each system manufacturer's chemical resistance charts. A test on a sample can complete that check.