Insulation Below Roof Deck

The project is in climate zone 4 seattle area and i want to have an open beam look in the ceiling.

Insulation below roof deck.

I would use polyiso with a top layer of eps as recommended in your blog post on the topic. This variation on the unvented attic design requires a thermal barrier such as an approved intumescent coating. Below you will find links to company and product information for manufacturers and suppliers listed in the roof and deck insulation section of sweets. Insulation above the roof deck or air vapor impermeable insulation below the roof deck is needed for condensation control in an unvented roof.

I m considering a roof design that would place all the insulation above the roof deck with no insulation below. Placing a layer of fluffy insulation below the roof deck would needlessly complicate the. Note that table r806 5 indicates the amount of insulation above the roof deck or air impermeable insulation below the roof deck required for condensation control assuming minimum required total insulation as indicated in section n1102 building thermal envelope. With rising heating and cooling.

07 22 00 roof and deck insulation. During cooler night times and in winter periods the deck temperature can then be below the dew point of the interior air. Gaining in popularity is the design approach of insulating on the underside of the roof deck and leaving the spray foam exposed to the occupants below. The roof deck is cold wood decks without insulation above them will readily equilibrate to the exterior temperature.

Hence the term cold decks construction materials wood based products absorb moisture. The greater your home s thermal resistance factor or r value the more energy efficient it is.