517 A.2d 225 Derry Township School District, Appellant v. Suburban Roofing Co., Inc., Appellee. Commonwealth Court of Pennsylvania.Argued September 8, 1986 November 7, 1986. School district — Public contracts — Jurisdiction — Judicial Code, 42 Pa. C. S. § 742 — Scope of appellate review — Judgment n.o.v. — Equitable estoppel — Plank replacement — […]