Cementing a New Era

White cement doesn’t usually make headlines. It quietly does the job, curing beneath the waterline while builders move on to the next dig. But now, it’s stepping into the spotlight. And when the backbone of every plaster finish starts evolving nationwide, it’s worth putting down the trowel and paying attention.

Cement production is one of the largest sources of carbon dioxide emissions worldwide and the second-most consumed product after water. The industry is under growing pressure to shrink its environmental footprint, so manufacturers are reformulating white cement by increasing the amount of finely ground limestone in the mix.

Traditional white cement contained up to 5% limestone. The new formulation — Portland limestone cement — raises that to around 15%, with more increases expected as carbon-neutrality targets move toward 2050. The added limestone reduces the amount of clinker needed, which is the most carbon-intensive part of cement manufacturing. The result: lower emissions without changing the craftsmanship or application practices pool builders have relied on for decades.

“The whole process was driven by environmental concerns and trying to have a friendlier product to put in the marketplace,” says Art DeVecchis, vice president of sales, marketing and logistics at Federal White Cement.      

“This isn’t a fad or a factory whim,” adds Phil Greggs, technical director for Southern Grouts & Mortars and chair of the National Plasterers Council Research Committee. “It’s a global initiative. The cement industry is reducing carbon emissions, and this is the direction everything is moving.”

This isn’t a fad or factory whim … It’s a global initiative.”

Phil Greggs, Southern Grouts & Mortars

This shift isn’t untested. The gray cement industry in the U.S. and other global markets transitioned years ago, proving higher-limestone formulations work reliably at scale. White cement is simply following the same path.

The new formulations entering the pool market — ASTM C595 (PLC/Type 1L), which contains up to 15% limestone, and ASTM C1157, which can include up to 35% limestone — are designed to deliver the same performance profile as traditional ASTM C150 white Portland cement. In fact, pool builders may have already worked with these updated materials without realizing it. 

“We’ve been exclusively manufacturing the Portland limestone cement for the last two years,” DeVecchis says. Builders using the new formulation say the material handles much like traditional white cement, with only minor differences.

Because pool plaster is placed, finished and submerged faster than most cement products, NPC has been aggressively studying how limestone-rich formulations behave in real pool environments. Results from the first round of lab tests mirror what early adopters have seen.

“The data is strong, and performance has matched or exceeded expectations,” Greggs says. “Everything we’re seeing so far aligns with the results builders expect.”

First, the new formulations need slightly more water to reach the same workability. Limestone is softer than clinker, so when they’re ground together, the limestone becomes finer. Finer particles create more surface area, requiring more water to wet out. Greggs’ advice to builders: mix until it feels right.

“It’s a little more thirsty,” DeVecchis says. “It just wants a touch more water to get to the same place.”

While the lab work reflects these shifts, crews in the field report only minor practical adjustments. Ryan Black, lead foreman at David Cooke Plaster Co., says the changes are noticeable but not disruptive. “The biggest change is we do use more water in our mixes to achieve the correct viscosity,” he says. “The bubbles hang around longer on plaster jobs, too. But overall, I haven’t noticed much change.” 

NPC also confirmed a modest increase in set time — a slightly longer window that most crews describe as a welcome breather on busy days. “We’re seeing it take maybe 20 or 30 minutes longer,” Greggs says. “Not a big deal.”

The critical takeaway was that the structural indicators were solid. Early compressive strength stayed strong, matching — and, in some samples, outperforming — traditional white cement. Limestone particles, once considered filler, acted as nucleation sites, helping hydration along. Tensile strength, shrinkage and porosity behaved the same way: steady, predictable and in line with what builders expect from a durable finish.

“The numbers matched what we were seeing in the field,” Greggs says. “No surprises, no red flags.”

Black echoed that sentiment from the jobsite level. “I was expecting challenges from this new cement,” he says. “To date, I have not noticed anything special.” For many crews, the transition has been quiet and uneventful.

The additional limestone came with an unexpected perk. Because limestone is naturally bright, the cement produces a cleaner, more uniform base color — a noticeable benefit for both white and likely pigmented finishes. “We’re seeing a slight uptick in brightness with the updated blend,” DeVecchis says. “The higher limestone content isn’t muting the finish — it’s enhancing it.”

With the fundamentals confirmed, NPC has started testing pigmentation. Because pigments can behave differently depending on cement composition, the research committee is studying color strength, shade uniformity and long-term stability to ensure builders will have clear, evidence-backed guidance on how their finishes will look and age. These findings will be presented at the NPC Annual Conference in February, with more details continuing through 2026.

Climate behavior testing is also underway. NPC is studying how the formulation responds in freeze-thaw conditions, high heat, arid regions and humidity swings. Early reports from the field align with the lab’s first indicators, showing stable, predictable performance across regions.

“This shift is part of a bigger global effort,” DeVecchis says. “And we see it as a positive — for the environment and for the industry.”

The future of pool finishes isn’t just on the horizon. It’s already on the truck.