It is an acceptable practice to install a new roof over an existing roof membrane system provided that the roof deck is.
Roof deck insulation board.
Rigid roof insulation board.
Bare foam board one sided sheathing board or double sided which is also reference as structural insulated panels.
Tested in accordance with astm e84 its surface burning characteristics are flame spread 0 and smoke developed 0.
5 8 densdeck roof boards can replace any generic type x gypsum board in.
Rigid foam board is just above the roof deck or an exterior insulation option.
Insulation above the roof deck or air vapor impermeable insulation below the roof deck is needed for condensation control in an unvented roof.
The ratio of insulation above the roof deck or air permeable insulation below the roof deck is a matter of climate and interior conditions.
How to install insulation board over an existing roof membrane.
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Composed of a closed cell polyisocyanurate foam core bonded in the foaming process to retroplus roof board on one side and a glass reinforced facer on the other.
The previous four options are all used beneath the roof.
Retroplus roof board is an expanded perlite mineral aggregate board.
Explore owens corning commercial roof and roof deck insulation products to help with your next building project.
Densdeck roof boards are fm tested and approved as the only 1 2 gypsum product to meet the calorimeter requirements for conventionally insulated decks.
It typically has 3 variations.