The insurer relied upon the Alberta Court of
Appeal decision in Ledcor Construction Ltd v. Northbridge Indemnity Insurance Co. («Ledcor»), [5] which excluded from coverage the
cost of replacing glass windows that suffered damage
during the cleaning
process caused by the faulty workmanship of a trade contractor on the basis that repairing the windows would be «making good faulty workmanship» since the damage was the direct result of the cleaning carried out by the trade contractor.