Insulating The Roof Deck

Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.

Insulating the roof deck. Generally more insulation is needed for condensation control in colder climates. Insulating the floor and the roof this is certainly the most interesting solution when the attic is also going to be used. Also the higher the indoor humidity the more insulation is needed to avoid condensation. However it is the most labour intensive and most expensive option.

Cold roofshave insulation between the rafters allowing for ventilation space below your roof deck. Rigid foam insulation boards. There are different roof decks that require different insulation techniques. Add insulation above the roof deck this approach fits current building science thinking in terms of putting the thermal control layer on the outside of the building structure.

For the same reason insulation shouldn t touch the roof s underside. The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow. The advantage of this approach is that the heat that is generated and circulated in the floors below is not lost through the attic floor into the rooms above. When installing rigid insulation in an attic to be finished as a living space you must provide a route by which hot air.

Insulating the roof is a priority if the ceilings of your home happen to be part of the roof deck as is the case with cathedral ceilings. The ratio of insulation above the roof deck or air permeable insulation below the roof deck is a matter of climate and interior conditions. Typically this would be achieved by adding polyiso insulation above the plywood deck. Staple plastic or foam baffles to the roof sheathing near the eaves to keep the material away.

Hot roofsare insulated above the rafters. You may also insulate your roof to help regulate the temperature in an attic that is a part of your living space. In addition to installing the foam board on the underside of the roof deck you can attach it to the bottom edges of the. When installing a foil faced foam board insulation.