It was an old and aged Hypalon membrane exposed on Airport roof. Many defects were found in the seam joints and non-watertight poor workmanship details which causes major water leakage especially after a heavy rain. Due to existing sandwiched panel roof waterproofing system, it was not allow and possible to remove the old waterproofing. The Owner wants a reliable waterproofing system to cover the whole old roof and requires that it does not cause any additional roof leakage.
To consider the weathering effect (e.g. rain and wind) and concerns by Owner during application, it was suggested fast-sprayed PUR system, Sikalastic GET 1000 and ExcelTop H.R. from Sika Dyflex, as fully adhered LAM. To ensure good adhesion with aged Hypalon, sample was cut and sent to ask Dyflex making a lab test to find out if Sika Eau Primer can achieve the requirement. The substrate was power washed before applying primer.