Cold Storage and Freezer Floor Coatings
Be straight about the temperature rating
PPC lists the Krete Slurry SL service range as 26.5F to 185F. That covers coolers, chill rooms, produce rooms, refrigerated processing and refrigerated docks, which is most of the cold storage work in South Florida. It does not by itself cover a blast freezer or a deep freeze warehouse held well below that. If your room runs colder than the stated range, do not let anybody, including us, tell you a product is rated for it off a web page. Tell us the holding temperature and we will take the actual room conditions to the manufacturer and come back with a written answer. That is a slower reply and a better floor.
What actually fails on a cold room floor
The door line, not the middle of the room
Every time a freezer door opens, humid Florida air walks in and condenses on the slab. That strip inside the threshold is wet, then frozen, then wet again, dozens of times a day. It is the only part of the floor that sees a real freeze and thaw cycle and it is where coatings delaminate first. It needs the same system as the rest of the room, terminated properly at the threshold, and it needs the non slip finish even if the rest of the room is smooth.
Thermal shock at the dock, not inside the box
A 90F loading dock and a 34F cooler are twenty feet apart. A pallet jack runs that gradient all day, and a wash down at the dock sends warm water across the threshold. Inside the box the temperature is stable and undramatic. At the doorway it is not, which is why a floor system in cold storage is chosen for thermal shock resistance rather than for its cold rating alone.
Water under the coating, which is a slab problem
Zero water absorption matters here in a way it does not in a dry warehouse. Any porosity in the floor surface holds condensate, and condensate in a cold room is not going to evaporate. It sits, it freezes, it expands. The Krete slurry is listed at 0% water absorption, and that is the reason it is the default here rather than a thin film epoxy.
Downtime and cure, and the part that surprises people
Manufacturer figures at 72F.
- Krete Slurry SL. Foot traffic 12 hours, heavy traffic 24 hours, full chemical cure 5 days.
- Krete Topcoat. Light foot 24 hours, full chemical cure 7 days. Place it within 24 hours of the slurry and no prep is needed, past that it has to be diamond ground.
- Temperature during install. Do not apply below 50F. Keep the floor above 40F for the first 24 hours. That is the constraint that sets the whole schedule.
- Dock and vestibule coatings. EF-155 recoats in 2 to 4 hours with foot traffic in 6 to 8 at 68F. EF-150 recoats in 6 to 8 with foot traffic in 8 to 12. Both apply on substrates down to 32F.
The realistic sequence for a working cold store is this. Empty the room and move product out. Bring the room up and hold it, then let the slab dry, which is days not hours on a slab that has been frozen for years. Shotblast, detail the drains and the threshold, place the slurry, topcoat it inside the 24 hour window. Hold the room warm through the cure. Then pull the temperature back down slowly rather than slamming it, and only load product once the manufacturer's chemical cure time has passed. The step people skip is the slow pull down, and it is free.
Prep and moisture in a Florida cold store
The prep is a shotblast to CSP 2 to 3 with containment and HEPA extraction, same as any urethane cement job, with one addition: the slab has to be dry at the surface after the warm up. A slab that has been at 34F for a decade will sweat as it comes up, and placing over a damp surface is the fastest way to waste a shutdown.
On slab moisture testing, the Krete Slurry SL page states that moisture testing is not required before install, which removes one of the usual arguments. That does not remove the need for the surface to be dry on the day. Those are two different things and they get confused constantly. For the dock apron and vestibule, if you are putting an epoxy there rather than urethane cement, test the slab and use the EF-160 moisture vapor barrier if the numbers call for it. It handles emission up to 25 lbs per 1000 sq ft per 24 hours at 100% relative humidity.
Quantities change with thickness and with how much threshold and cove detail the room carries, so use the coverage guide rather than a square foot rule, and pull the sheets from technical data sheets.
Where to go next
This page sits under our commercial and industrial flooring overview. If the cold room is part of a processing plant, start at food plant floor coatings. If it is a kitchen walk in, see commercial kitchen flooring. For the dry warehouse around it, see warehouse floor coating.