Historic wooden shingle roofs - Intro
|>>Introduction||>>Roofing practices to avoid|
|>>History of wood shingles in America||>>Maintenance|
|>>Historic detailing and replacing roofs||>>Taking it further|
|>>Specifications for the replacement roof|
By Sharon C. Park, AIA
Wooden shingle roofs are important elements of many historic buildings. Thespecial visual qualities imparted by both the historic shingles and theinstallation patterns should be preserved when a wooden shingle roof isreplaced.
On a wooden shingle roof, it is important not only to match thesize, shape, texture, and configuration of historic shingles, but also to matchthe craftsmanship and details that characterize the historic roof. Properinstallation and maintenance will extend the life of the new roof.
This requires an understanding of the size, shape, and detailing of thehistoric shingle and the method of fabrication and installation. These combinedto create roofs expressive of particular architectural styles, which were ofteninfluenced by regional craft practices. The use of wooden shingles from theearly settlement days to the present illustrates an extraordinary range ofstyles. Readily available and inexpensive sawn shingles were used not only forroofs, but for gables and wall surfaces.
Wooden shingle roofs need periodic replacement. They can last from 15 to over60 years, but the shingles should be replaced before there is deterioration ofother wooden components of the building. Appropriate replacement shingles areavailable, but careful research, design, specifications, and the selection of askilled roofer are necessary to assure a job that will both preserve theappearance of the historic building and extend the useful life of thereplacement roof.
Unfortunately, the wrong shingles are often selected or are installed in amanner incompatible with the appearance of the historic roof.
There are a number of reasons why the wrong shingles are selected forreplacement roofs. They include:
- the failure to identify the appearance of the original shingles;
- unfamiliarity with available products;
- an inadequate budget;
- or a confusion in terminology.
In any discussion about historic roofing materials and practices, it isimportant to understand the historic definitions of terms like "shingles,"as well as the modern definitions or use of those terms by craftsmen and theindustry.
Historically, from the first buildings in America, these woodenroofing products were called shingles, regardless of whether they were theearliest handsplit or the later machine-sawn type. The term shakeis a relatively recent one and today is used by the industry to distinguish thesawn products from the split products, but through most of our building historythere has been no such distinction.
Considering the confusion among architects and others regarding these termsas they relate to the appearance of early roofs, it should be stated that thereis a considerable body of documentary information about historic roofingpractices and materials in this country, and that many actual specimens ofhistoric shingles from various periods and places have been collected andpreserved so that their historic appearances are well established. Essentially,the rustic looking shake that we see used so much today has little in commonwith the shingles that were used on most of our early buildings in America.
Throughout this brief, the term shingle will be used to refer to historicwooden roofs in general, whether split or sawn, and the term shake will be usedonly when it refers to a commercially available product.
This brief discusses what to look for in historic wooden shingle roofs andwhen to replace them. It discusses ways to select or modify modern products toduplicate the appearance of a historic roof, offers guidance on properinstallation, and provides information on coatings and maintenance procedures tohelp preserve the new roof.
-- NPS Preservation Brief 19