Historic Zoning Commission

Edgewood-Park City H-1: Level II

9-G-12-HZ

Applicant Request

Level II. Replacement/repair

Removal of original slate roof shingles and replace with decorative composite metal shingles.

Site Info

Two-and-one-half-story frame with weatherboard wallcovering and vertical board beltcourse. Cross-gabled roof with patterned slate covering. Two-story bay on east elev, rafters, sawn wood bargeboard and incised garland motif. Irregular plan.

The slate roofing, which was original to the house, has been removed. Decorative composite metal shingles have been installed on front portions of the roof. The applicant asserts that both prohibitive cost and lack of availalbility of a similar material were factors in replacing the slate. The applicant's contracter asserts that the slate was not repairable.

STAFF FINDINGS-- Part I (removal of slate rather than repair)
1) Excerpt from Preservation Brief 29, Technical Preservation Services, National Park Service, DOI, 1992: "The relatively large percentage of historic buildings roofed with slate during the late nineteenth and early twentieth centuries means that many slate roofs, and the 60 to 125 year life span of the slates most commonly used, may be nearing the end of their serviceable lives at the end of the twentieth century." (Jeffrey S. Levine, The Repair, Replacement & Maintenance of Historic Slate Roofs)

2) Slate remnants from the former roof covering indicate some degree of deterioration.

3) The Edgewood-Park City recommend to applicants to "try to repair or reuse such materials as slate and tile when they are available."

STAFF FINDINGS -- Part II (use of an alternate material to replace the slate)
1) The Park-City Edgewood Design Guidelines allow for substitute roofing materials when the original material is not readily available or when it is "cost is prohibitive."

2) The applicant asserts that their contractor provided information that similar slate roof shingles would have had to have been shipped from California.

3) In a recent slate re-roofing application, there was a waiting period for slate to be mined from quarries.

4) Slate tile substitute materials are available in clay, metal, polymer and resin. There are at least two instances in which "rubber" substitute slate materials that have been utilized in other area are exhibiting curling a the edges.





STAFF FINDINGS -- Part III (replacement with decorative metal shingles)
1) The removed slate roofing was original to the house and was/is still found on several George Barber houses in Knoxville historic districts.

2) There are at least two other remaining slate roofs on Queen Anne houses (thought to be Barber Houses) on Washington Street.

3) The "patterned slate roof covering" is identified in the 1986 survey as a character-defining feature of the house.

4) In Knoxville's historic districts, the most typical evolution from more expensive roofing materials has been to change to modern asphalt shingles as a lesser expensive material. The roof on the one-story portion on the rear of the subject house is currently asphalt shingles.

5) The metal shingles add a historic decorative element that was never utilized on this particular house and not documented as typically utilized in this district or this city. However, standing seam sheet metal roofing was and is still utilized in this district and other Knoxville historic districts. The aesthetic and patterning of standing seam metal roof is different from that of a metal-shingled roof.

6) Documention submitted by the applicant indicates that decorative metal shingles (original or not) have been utilized on George Barber houses outside of Knoxville in cities such as Strasberg, Illinois; Laurens, SC; and Sedan, Kansas.

6) A vintage ad for Chattanooga Roofing and Foundry from the McClung Collection submitted by the applicant provides evidence that metal roofing shingles were at some early point manufactured there. Metal roofing, including both tin and galvanized metal shingles, was advertised in Barber's pattern books.
Barber often specified "shingled" roofs in his pattern books, but the type of shingles are not specified (e.g., plans in A Cottage Souvenir No. 2).


EDGEWOOD-PARK CITY DESIGN GUIDELINES

ROOFS pp. 14-15
A roof is one of the most dominant features of a building. . . The houses in the Edgewood-Park City Historic District may have been roofed with slate, tile, wood shingles, metal, or with asphalt shingles, sometimes cut in over-size, shaped patterns. The modern building materials that are available may limit a property owner's access to roofing materials, but it is important that owners try to repair or reuse such materials as slate and tile when they are available. Printed and sculptured fiberglass shingles can also be used to duplicate the look of original roofs. If replacement materials are not available or are prohibitively expensive, intact historic roofing materials should be used on the visible elevations, with replacement materials used at the rear or on a less visible section of the roof.

The architectural features associated with a roof should be saved. These include attic vent windows, finials, roof cresting, molding, dormer windows, complex slopes and intersecting gables. If built-in gutters are present on the house, they should be repaired so that the original appearance of the roof is recaptured.

Although the historic zoning commission does not regulate colors, it is suggested that roof colors, which will
be visible for the lifetime of the roof, be dark in color to mimic the roof colors that were present when the buildings were new.

1) . . .Replacement roofs must copy the shape and pitch of original roofs, and the soffit, fascia and trim detail between roof and wall should mimic the original.

3.) Repair or replace roof details (chimneys, roof cresting, finials, attic vent windows, molding and
other unique roof features). Use some of these details in designing new buildings.

4.) Materials used in roofing existing buildings or new construction shall duplicate original roofing
materials as much as possible. Asphalt or fiberglass shingles can be appropriate, as are slate, standing
seam metal, or metal or wood shingle roof coverings. The color of roofing materials should be a
dark green, charcoal gray or black or dark reddish brown, to simulate the original roof colors.




SECRETARY OF INTERIORS STANDARDSparticularly applicable to this proposal:

2. The historic character of a property shall be retained and preserved. The removal of historic materials or alteration of features and spaces that characterize a property shall be avoided.

3. Each property shall be recognized as a physical record of its time, place and use. Changes that create a false sense of historical development, such as adding conjectural features or architectural elements from
other buildings, shall not be undertaken.

4. Most properties change over time; those changes that have acquired historic significance in their own right
shall be retained and preserved.

5. Distinctive features, finishes, and construction techniques or examples of craftsmanship that characterize a property shall be preserved.

6. Deteriorated historic features shall be repaired rather than replaced. Where the severity of deterioration requires replacement of a distinctive feature, the new feature shall match the old in design, color, texture, and other visual qualities and, where possible, materials. Replacement of missing features shall be
substantiated by documentary, physical, or pictorial evidence.


FURTHER STAFF RECOMMENDATIONS for approving this application:

If there is a desire in the Edgewood-Park City Historic District to make the exception and set the precedent that alternative materials are not required to simulate or replicate the original material or design in that district, staff recommends that this exception be limited to slate roofing materials due to their expense, rather than setting the precednent for changes in appearance and material for all building materials. If this application for replacing slate with decorative metal shingles is approved, then the neighborhood and HZC accepts that the basis for approval is that since decorative metal shingles were utilized on similar houses in other cities and manufactured as nearby as Chattanooga, it is reasonable to deduce that they may have been utilized in Knoxville, and may be approved, even if no evidence exists that they were utilized on the particular house subject to review.