Limestrong Pozzolan Lime Plaster was Developed by Stan Petersen


Under the guidance of a renowned expert in old-world masonry and lime plastering, Hess Pumice formulated a natural plaster product that puts the strength, durability and beauty of the old-world masters in the capable hands of today’s plasterers.

Stan Petersen, renowed expert in natural plaster finishes

Stan Petersen, the Man Behind LimeStrong

Stan has a long lifetime of experience formulating and applying natural plasters and mortars. His expertise as a master plasterer and his deep knowledge of old-world plaster formulas and application techniques is recognized world-wide. That “world-wide” term is easy to throw around, but in Stan’s case, he is a true globetrotter, willing to go wherever his expertise is needed...historical building restorations in Europe, high-end custom homes in Aspen Colorado, or a resort village complex in the Baja on the shores of the Sea of Cortez.

OLD-WORLD WALL FINISHES: CHARMING DURABILITY. While many simply settle for mediocre and common, there are those out there who are much more discriminating about the eye appeal and green-cred of not only the materials used to construct their home or business structure, but the finish of it as well. There is a delighted group of those discriminating types lucky enough to have known somebody who knew somebody who knew Stan Petersen. As Stan is fond of saying: “I count among my best friends my former clients. That wouldn’t be the case if my finishes had failed.”

old-world plaster finishes

A STUDENT OF THE OLD (WORLD) SCHOOL. Stan comes from a line of masons and plasterers—his grandparents immigrated to America from Norway and brought the old-world craftsmanship and savvy with them. From the time Stan was a boy, he was working with his father building masonry and wood structures and finishing them with plaster. It was during those formative years around his father and uncles that Stan developed an intense desire to fully understand the materials he was working with. It was not enough to simply apply a beautiful lime-washed plaster finish, he wanted to understand and master the delicate chemistry that made it work so well and last so long. As the demand for his skills took him beyond the American West and into Europe, Mexico and Central America, he relentlessly sought out and learned from those master craftsmen who formulated and applied the neglected art of old-world plaster and mortar. Whether is was learning from master masons and plasterers in Scotland, or living and working among Mexican villagers in Chiapas learning from the plaster “maestros” he found there, or in Morocco learning the traditional craft of tadelakt lime finishes, Stan has been a voracious student of tried-and-true old-world techniques and sustainable, economical mix designs.

“My professional education has been as complete as it has been colorful,” says Stan, “not from some school somewhere—no college teaches such things—but from the maestros themselves. Take additives, for example,” he continues. “Different regions use different additives to lend desirable characteristics and color tints to their plaster finishes. Deep in the hot humid jungles of southern Mexico I learned to brew barrels of Nopales cactus to get a juice that helps make lime plaster impervious to the wet tropical climate. In other places it was three-day-old cow dung. Or ox blood. Or egg whites. Fascinating.”

Through it all, Stan learned, applied what he learned, shared what he knew with others, and relentlessly expanded his world-renowned expertise.

lime plaster interior finish in LDS tabernacle

WORLD RENOWN. When plans are made to preserve, restore, or even recreate the character and integrity of the beautiful lime finishes in beloved historical structures, experts turn to Stan Petersen. When actor and director Sam Wanamaker led the charge to faithfully recreate Shakespeare’s Globe Theatre in the London Borough of Southward, Stan was hired as the supervising mixologist for the lime plaster used to accurately reconstruct the harrowed finishes on that painstakingly researched and lovingly recreated building.

Stan consulted on restoration and preservation plans to protect the pioneer craftsmanship of the historic Mormon Tabernacle (including a earthquake-proofing retrofit) in Salt Lake City.

The list goes on. It’s safe to say that Stan Petersen knows more about formulating and applying traditional lime finishes than any single person in the U.S.

the pure white pozzolan component of LimeStrong Plaster

THE BEST POZZOLAN FOR HIS PLASTER. As the Romans discovered, lime cements and plasters are at their strongest when fine-grained pumice (which they called pozzolana) is present in the mix. Stan, of course, knew that, and would scrounge around the local job area for a pozzolan (typically pumice) to use in his lime plasters and mortars. And then came the day that Stan discovered the ideal pozzolan for his formulations. In the corner of southeast Idaho was a pumice mine yielding a pure white pumice that proved to be the perfect performer for Stan’s go-to lime plaster formulation. From then on, whenever logistically feasible, he sourced Hess Pumice exclusively for his lime plaster and mortar projects.

Several years later, Stan was approached by Hess Pumice to formalize his lime-and-pozzolan plaster recipe for a bagged product. As Stan put it, “we took the formulation I was custom mixing at every job and put it in a bag.” The result is an amazing product that eschews the use of problematic Portland cement and embraces a finishing material is that is economical, sustainable, durable, breathable, flexible, consistent, beautiful, and wonderfully forgiving to work with.

More information about Stan and his work can be found at his website:

Hess Pumice Products

Hess Pumice mines and refines the world’s purest deposit of white pumice and ships it world-wide. Recognizing the exceptional and unique quality of their pumice deposit, Hess built sophisticated processing plants to support active development of new pumice-based products for a wide variety of industrial applications. Sometimes it is but a simple matter of recovering highly-effective, yet mostly forgotten processes and bringing them back to market. Our LimeStrong product is one of those successes in our efforts to improve the poor performance of modern concrete and other Portland cement-based products. Other examples include:

Hess Pumice Processing Plant One, Malad Idaho USA

Pozz and UltraPozz. Modern concrete has a problem. It simply doesn't last. The key problem lies in the use of Portland cement itself. Replacing some of the cement with natural pumice pozzolan (pozz) ignites a secondary pozzolanic reaction within the curing concrete that subjugates deleterious compounds and super-charges concrete performance in terms of strength and density. This dramatically improves cured concrete's ability to resist the attacks of sulfates and chlorides and protect the reinforcing steel within, impede freeze-thaw-cycle damage, mitigate heat-of-hydration cracking, stop efflorescence staining, and, for regions with reactive aggregate, shut down the highly destructive alkali silica reaction (ASR) process.

Hess Pozz grades are widely used in Glass Fiber Reinforced Concrete (GFRC) products and oil well cements, to name but two.

Cementitious Pozzolanic Grout. Produced through our US Grout division and distributed globally by Avanti International, our microfine and ultrafine cementitious grout products are used to stabilize and strengthen soils and seal cracks as small as 6 microns in concrete structures and rock. Our pozzolanic grouts are a strong, economical, long-lived, safe-to-use alternative to expensive chemical grouts.

Our efforts to improve concrete and cementitious products are but one aspect of our on-going pumice-product development culture.

Non-Crystalline Silica (NCS) Functional Filler. Our ability to consistently and accurately process pumice to incredibly fine grades allows us to market six NCS grades for functional fillers, extenders, and performance boosters by the paint and industrial coatings industries. The rubber and plastics industries and the cosmetics industry also utilize our safe NCS grades.

pumice grow media for aquaponics or hydroponics grow beds

Soilless Grow Media. Ultra-efficient growing systems—such as hydroponics and aquaponics systems—rely on soilless grow media to achieve rapid growth and abundant harvest. ’PonicsStone Grow Media is an ideal and enduring media for grow-bed type systems. The physical structure of the natural pumice stone makes it a perfect fit for intensive growing applications.

The physical characteristics and chemical makeup of our pumice make it very versatile. And the fact that pumice is naturally calcined by virtue of its volcanic origin means no energy-intensive processes are necessary to produce a ready-for-market product. In terms of sustainability and green-cred, that’s a big deal.

For more about Hess Pumice and our variety of pumice products, visit the Hess Pumice website.

Contact us for more information, availability, and training in the use of our LimeStrong products.

Limestrong is a product of Hess Pumice

Brian K. Jeppsen
(208) 766-4777 x111