St. Ann School
To Remove or not to Remove? That was the question. Widespread delamination of the gypsum plaster skim coat from the cast concrete ceiling presented a safety problem in this school built in the early 1950s.
Two remedial options were considered: 1. Scrape off the existing plaster and then re-plaster; or 2. Re-adhere the existing plaster to the concrete. Option 2 was selected and John Tiedemann Inc./HPCS USA was commissioned to design a treatment program that was more economical than Option 1. The treatment program involved the development of a system to inject HPCS AD 25 Gel adhesive to reattach the plaster to its concrete substrate. Independent testing, designed by engineer, John Dilassio, and conducted by Ken Follett of Quality Restoration Works, confirmed the success of the treatment program.