The Sawyer Homestead
320 East Front Street
Monroe, Michigan 48161-2047
The historical integrity of this National Register site could be improved by application of the original roofing material .A problem is that no one can find any documentation of what that roofing material was. An engineering analysis of the structure questions the structural integrity of the roof supporting system to hold the weight of slate. A good metal roof would still be in place so wooden shakes may have been used. Under these circumstances, asphalt shingles are acceptable although a period material such as metal would be acceptable as well at a higher cost.
The webkeeper has unfairly objected to the use of asphalt out of ignorance of the National Register guidelines that apply to roofing replacement. An apology is extended to anyone who was offended by remarks on that subject.
Jeff Green Replies>
In this type of situation, i.e., installing a new roof, the Secretary of the Interior’s Standards and Guidelines would frown more upon the installation of a “period” material that could not be documented than a new material that can easily be distinguished, in years to come, from historic materials. In this case, we know that asphalt would not have been a material original to the building and so by installing it we are signaling that there is a legitimate question as to what was there. Someone may find evidence or documentation in the future that answers the question of “what type of roofing material was originally used on the building?” and thus allow changes to be made based upon actual documentation, not simply conjecture.
Additionally, the goal in selecting the asphalt shingles that were ultimately used on the Sawyer House was to provide something that was visually appealing, but not overwhelming. The shingles selected are a high-end product that have the coloring and size of slate that blends in well with the structure, but does not dominate it or become the primary visual component. Likewise, given the circumstances, we would have been remiss had we not considered cost and long-term durability, which this product offered. (Just a further note on this subject: While there are asphalt roof products on the market that are supposed to simulate wooden shakes, as well as faux slate products made out of a variety of materials, they either don’t convey as good of a visual appearance as the shingles selected, or their long-term durability is suspect – thus another reason to go with the GAF shingles at this point in time.)
So, regarding your statement on the web, something along the lines of “…asphalt shingles are acceptable as a substitute material given the fact that the original roofing material could not be identified. A period material, such as metal or wooden shakes, could be appropriate provided there is adequate documentation, however, associated costs might be higher than that of asphalt products” might provide better clarification for those that have not had a lot of exposure to preservation.
Thanks for making the effort to clarify this point. As I indicated when we spoke on the phone, recommendations made by staff related to these types of issues are not taken lightly. We hope the recommendations and analyses reflect this fact – we will now need to convince City Council of the same.
If I can provide any other information on this issue, or if you would like to discuss other items or issues related to preservation feel free to contact me at 384.9106 or at this email address.