Continuous Insulation On Attic Eave Wall

Covering up the soffit vents with loose fill or batts which can happen if you stuff insulation along the eaves is a huge no no.

Continuous insulation on attic eave wall. Unlike typical insulation installed between framing members continuous insulation provides an uninterrupted thermal barrier for unparalleled performance. A vented attic where insulation is placed on an air sealed attic floor is one of the most underappreciated building assemblies that we have in the history of building science. The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow. So i ll start by saying something that might sound controversial but really isn t.

Install raised heel trusses or use another roof framing method that allows space to install insulation over the top plates of the exterior walls or install high density insulation to achieve an r value that meets or exceeds code minimums for attic insulation. Design the roof to allow full insulation over the top plates of the exterior walls. For decades the typical solution to this problem was to install ventilation baffles near the eaves connecting the air space above the soffit vents with the attic and then to install as much fluffy insulation usually fiberglass or cellulose as there was room for between the top plate of the exterior wall and the ventilation baffle. 85 minimum to bs en iso 14021.

R 38 shall be deemed to satisfy the requirement for r 49 wherever the full height of uncompressed r 38 insulation extends over the wall top plate at the eaves. What is continuous insulation. Figure 3 unvented roof assembly at eave retrofitted with rigid foam spray foam and taped top edge of existing house wrap or building paper to seal the top of wall to roof transition while spray foam is installed to the underside of roof sheathing to floor sheathing to inside face of rigid insulation backing and to inside face of existing wall sheathing to insulate and air seal the attic. Gables to be insulated as exterior walls.

The 2015 irc requires r 49 insulation for ceilings with attic spaces. Flexible formaldehyde free glass mineral wool. Pa302 1 ceilings with attic spaces n1102 2 1 r402 2 1. However there is an exception.

For the same reason insulation shouldn t touch the roof s underside. Attic insulation unvented attics must be air sealed at roof deck eaves gables and penetrations. So much information has been devoted to the subject of roof venting that it s easy to become confused and to lose focus. Ensure meets any eaves insulation and or internal wall insulation to prevent cold bridge at eaves without blocking any ventilation paths required to loft space roof space.