Mario Machnicki holds a degree in chemical engineering from Europe, but his professional path in the United States began on construction sites. After immigrating in the early 1980s, he worked as a mason, primarily on new construction and occasional restoration projects.
Over time, he began to notice that many restoration repairs failed prematurely. Mortars cracked, masonry deteriorated, and surfaces needed to be redone after only a few years. These failures weren’t just superficial — they revealed a fundamental misunderstanding of historic materials and traditional construction methods.
Driven by a desire to do better, Mario began to study historic masonry in depth. Drawing on his scientific background, he investigated why modern techniques and materials often caused more harm than good. He traveled to Europe to attend courses in conservation, learned from traditional craftsmen, joined preservation societies, and became actively involved in international conferences focused on architectural restoration.
When he decided to start his own business, he began with small-scale restoration projects — applying what he had learned to real-world conditions. These early projects became a proving ground for his principles: compatibility, breathability, and respect for original materials.
As demand grew for both his craftsmanship and his understanding of traditional systems, he laid the foundation for what would become two influential organizations: Marion Restoration and U.S. Heritage Group.
Traditional masonry restoration demands more than technical skill — it requires materials that are compatible with historic construction methods. Through years of research and hands-on experience, Mario Machnicki recognized that modern cement products were often the root cause of premature restoration failure. The solution was clear: return to traditional lime mortars.
Lime mortars are breathable, flexible, and chemically suited to historic masonry. They allow buildings to manage moisture naturally and accommodate subtle movement without cracking.
Unlike cement-based products, they do not trap water or cause long-term damage to soft historic materials.
To address the lack of appropriate restoration materials in the U.S. market, Mario founded U.S.
Heritage Group in 1996. The company was created to manufacture and supply conservation-grade lime mortars, plasters, mineral paints, and breathable building materials — all tested in laboratories and based on proven European formulations. These materials are now trusted by architects, engineers, and preservation professionals across the country.
In parallel, Mario continued to grow Marion Restoration, applying these materials in the field using traditional methods. His team specializes in historic masonry repair, using authentic lime mortars to ensure every intervention is both historically appropriate and technically sound. Whether working on 19th-century brick, historic stonework, or ornamental plaster, the guiding principle remains the same: respect the original materials and support the building’s natural performance. This integrated approach — combining product development with field application — sets a new standard for traditional restoration services in North America.
Mario Machnicki has led or consulted on hundreds of restoration projects, including many nationally significant landmarks. His companies have been involved in:
These projects reflect his ability to integrate scientific analysis, traditional craftsmanship, and conservation ethics. His work focuses on compatibility, reversibility, and long-term durability — ensuring that restored buildings retain their character and integrity for generations to come.
Mario’s contribution to the field extends beyond project work. Through U.S. Heritage Group, he provides training programs, laboratory support, and technical assistance to professionals in architecture, construction, and conservation. His teaching emphasizes the science of masonry repair and the importance of using compatible materials in preservation. He has taught and lectured for:
He has contributed to the National Park Service’s Preservation Briefs, participated in ASTM technical committees for mortar testing, and presented at international conservation conferences. His insights have been featured in:
His work continues to influence best practices in preservation, both through the
materials he develops and the professionals he trains.
As a consultant, Mario assists institutions, architects, engineers, and owners in identifying material failures, developing long-term restoration strategies, and guiding projects toward historically and technically sound solutions. When needed, he also serves as an expert witness in restoration-related disputes, offering clarity rooted in science, experience, and conservation ethics.
