AUTHENTICITY
Rosendale 12M Mortar Used for Restoration of the American Museum of Natural History

Custom color-matched Rosendale 12M natural cement masonry mortar has been used for repointing of the historic south range of the American Museum of Natural History in New York. Mortar analyses of the 1892 landmark facade confirmed historic documentation of the use of natural cement in the building’s original construction. The reintroduction in 2004 of authentic Rosendale Natural Cement Products® created an opportunity to maintain this unique architectural treasure’s historic integrity.

Contractor: Nicholson & Galloway, Glen Head, NY
Architect: WJE Associates, Inc., New York, NY

Why Use Rosendale Natural Cement Products^®?

New Technical Note explains Authenticity, Compatibility, Sustainability and Economic issues favoring repair/rebuilding in kind with natural cement.

Natural Cement Prices to Drop

Edison Coatings Inc. has announced a price decrease on all of its Rosendale Natural Cement Products® to take effect on June 1, 2010. Increasing sales volumes and process improvements are reducing the costs of production, and the Company anticipates further future decreases. The June 1 price changes will average 20% lower than the pricing that was first instituted in 2005.

American Historic Cement Conference
March 30 -April 2, 2011
New York City

The Society for the Preservation of Historic Cements, Inc., in conjunction with the US Dept. of the Interior - National Park Service - Historic Preservation Training Center and the Association for Preservation Technology Northeast Chapter have announced that presentations are being sought for the American Historic Cements Conference.

“As historic cement buildings and structures continue to age, the unique challenges related to historic cement identification, preservation and sympathetic restoration have often been overlooked. The purpose of this conference is to enlarge our knowledge of the various cements used in the period from 1870-1920

A more complete program description and instructions for authors may be found at the conference web site at www.HistoricCements.org

ASTM Issues Revised Standard C10

ASTM C10, Standard Specification for Natural Cement,  reinstated in 2006, and updated and republished in 2007 and 2009, has again been updated in 2010. The new C10/C10M-10 version of one of ASTM’s oldest standards was modified to include performance requirements for quick-setting natural cement. The standard is available online at www.astm.org.

The standard connects contemporary natural cement to its historic roots. Conservators, engineers and architects specifying “natural cement meeting the requirements of ASTM C10”, can be assured they will get the authentic, traditional material used in thousands of 19th Century buildings and structures, and that it will meet the same structural performance requirements it was designed to meet over a century ago

ASTM STP 1494 - Natural Cement

A valuable book is available from ASTM. Entitled “STP 1494 Natural Cement”, the book incorporates new and historical materials, including:

• 10 original papers presented at the First and Second American Natural Cement Conferences
• Copies of the reinstated 2006 ASTM C10 Standard Specification for Natural Cement and the original 1904 cement standard
• Reprinted excerpts of rare historical materials, including Young (1817) on canal construction materials, Totten (1838) on tests of lime and natural cement for use in fortifications, Vose (1857) on masonry materials for railroad construction and Cummings (1898) on buildings and structures built using natural cement.

The volume may be ordered from ASTM International online at stp1494.htm

Fort Jefferson, Dry Tortugas National Park

Photo 1 (left) was taken during 2004 test applications of Rosendale Natural Cement Products® at Fort Jefferson, 70 miles off Key West in the Gulf of Mexico. Rosendale natural cement was used in the original construction of the fort, over 150 years ago. In 2005, work continued under the first major restoration phase, and Phase 3 began in late 2008. Photo 2 (below) was taken in 2010 of work completed in Phase 3.

Natural cement has proven far superior to lime-based restoration products in these demanding exposures. As a result, Rosendale Natural Cement Products® ^{were also recently used at Fort Sumter, Fort Moultrie and Fort Pulaski.}

Rosendale Natural Cement Products® are the authentic materials of construction used for large masonry and early concrete structures in the 19th and early 20th Centuries. It is prized for its fast set, allowing much more rapid construction than lime putty masonry mortars. It is also recognized for its exceptional durability under severe exposures.

At Fort Jefferson, much of the 150 year-old Rosendale cement mortar remains in excellent condition, in spite of the severe ocean exposure and over 100 years of neglect. Although its circumference is a quarter mile and there is a total lack of expansion joints, the structure shows no signs of thermal expansion related cracking or stress.