Yes. It is required in relevant national standard.
It depends on the requirements of the construction side and supervising unit. If they require an inspection in an authoritative third-party laboratory, the requirement should be met. 2. If there are no clear requirements being made, the inspection is unnecessary. Generally speaking, the manufactures will always provide a report that the geomembrane pass the test done by themselves. Unqualified product can't escape into the market. Besides, construction side will have an inspection in their own laboratory. If the reports given by manufacture and construction side all show that the product pass the test, more inspection is unnecessary. If they are not in accordance with each other, a further inspection should be done.
