3.1 To prevent movement of the deck during its lifetime, UPM ProFi Decking must always be installed on a rigid substructure frame.
3.2 Different sub-structure options exist depending on the deck design. The frame itself must be installed on a well draining hard load bearing surface e.g. concrete blocks, impacted stones, or concrete.
3.3 No matter what length, each deck board must be supported by at least three joists/support rails. Double joists/support rails (spaced 40 mm apart) must be installed at points where the ends of two deck boards meet.