Repairing a roof by reinforcing the historic materials which comprise roof features. Replacing an entire roof feature such as a cupola or dormer when repair of the historic materials and limited replacement of deteriorated or missing parts are appropriate. Failing to reuse intact slate or tile when only the roofing substrate needs replacement. Using a substitute material for the replacement part that does not convey the visual appearance of the surviving parts of the roof or that is physically or chemically incompatible. Replacement of damaged clay tile roof.
Examples can include a large section of roofing, or a dormer or chimney.
If using the same kind of material is not technically or economically feasible, then a compatible substitute material may be considered. The following work is highlighted to indicate that it represents the particularly complex technical or design aspects of rehabilitation projects and should only be considered after the preservation concerns listed above have been addressed. Designing and constructing a new feature when the historic feature is completely missing, such as a chimney or cupola. Creating a false historical appearance because the replaced feature is based on insufficient historical, pictorial, and physical documentation. Introducing a new roof feature that is incompatible in size, scale, material and color.