This tropic heat actually is the cause that the steel structure, which most roofs in that part of the world are built on, expands and contracts all the time. By doing so, the sun-battered steel structure causes the roof tiles to dislodge and slowly creates small openings between the roof tiles, through which rain water can run into, creating leaks that can cause much damage to plastered ceilings and electric wiring.
Sealection 500 is a spray-applied adhesive, which once applied, expands in place using water-blown technology, without CFCs, HCFCs, or ozone-depleting chemicals. Unlike traditional fiberglass insulation, Sealection 500 will maintain its performance; time and temperature have no effect on the spray foam insulation's R-value of 3.81 at 1 inch. Sealection 500 never deteriorates or decomposes. The product retains its shape and half-pound density over time, and never settles or compacts.
2. I talked to a building product supplier for WALLTITE spray foam, he is suggesting to use 2" or 3" of closed cell spray foam in the joists areas instead of the batts insulation. He says it will work with outboard rigid insulation. There is a location of a cantilevered floor area with steel beam so I may need to use spray foam to protect the steel beam. I would then be convenient continue to spray in the floor joist cavities and then apply 5" of polyiso outboard of the bottom cantilever floor sheathing.
Fill and seal expanding foam sealant is urethane Fill and seal expanding foam sealant is urethane foam designed to fill large areas quickly and permanently. Uses include filling holes cracks or gaps that require a complete airtight and waterproof seal but are too large to be filled with ordinary caulk. The foam expands approximately 3 times its original ...  More + Product Details Close

Roof Coating Seal