The dense greystone blocks of south Evanston and Rogers Park have their own roofing rules.
What a greystone roof actually looks like
Typically a 1900–1925 construction with a flat or near-flat (1/4-pitch) roof framed in heavy timber, original built-up tar-and-gravel surface, parapet walls on at least two sides, internal drains or scuppers to short downspouts, and a roof access via a bulkhead from the third-floor stair.
What fails first
Almost always the drainage and the parapet flashing — never the field membrane itself in the first 15 years. We start every greystone scope with a drainage redesign: clearing or replacing internal drains, properly sized scuppers, and where appropriate, tapered insulation to engineer a positive slope toward the drain points.
Our default system
60-mil mechanically fastened TPO in white or light gray (cool-roof rated, reduces summer cooling load and meets Evanston Climate Action goals), with through-wall counter-flashing at every parapet (never face-mounted or caulked), pitch pockets at every penetration, and walk pads at every roof-access point.
Lifespan and maintenance
A properly installed 60-mil TPO greystone roof, with annual maintenance, runs 22–28 years. Annual maintenance is what makes the difference — drain clearance, seam inspection, and flashing re-seal at any check point. We offer a $385/year residential maintenance plan for two-flats and three-flats that covers all of this.