THE CONSERVATION OF BUILDINGS CONSTRUCTED WITH PORTLAND, CONNECTICUT BROWNSTONE

Abstract

This Thesis describes and documents issues in the preservation of buildings constructed with Portland, Connecticut brownstone, a sedimentary sandstone formed some 185 million years ago. The stone was quarried along a three-quarter mile strip of the Connecticut River in Portland, Connecticut primarily during the last half of the nineteenth century. Due to its rich, earth-tone brown color and ease of quarrying and shipping, it was used as building stone for hundreds of America's monumental structures. This national historical significance has lead to the Portland quarries being named a National Historic Landmark in 2000. The harsh northern climates, to which most of the brownstone structures are subjected, along with improper stone placement, poor maintenance techniques and owner neglect, have lead to its extensive degradation. This thesis addresses the causes for this deterioration along with the physical and chemical composition of Portland brownstone. Deterioration causes come from both man made and environmental sources. The Thesis concludes with a thorough description and conservation analysis of a recently completed brownstone restoration project. The complete fayade restoration of the New Haven, Connecticut, City Hall represents the state of the art in brownstone deterioration analysis and employs a variety of conservation techniques. The appendix contains a checklist of the Guidelines for Assessing and Conserving Brownstone Buildings.