Continuous Insulation On Attic Eave Wall

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Continuous insulation on attic eave wall.

Climate zones 1 5 and 8 16 wall assemblies must not exceed a maximum u factor of 0 051 climate zones 6 7 wall assemblies must not exceed a maximum u factor of 0 065 mineral wool performance attic. 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. Gables to be insulated as exterior walls.

Unlike typical insulation installed between framing members continuous insulation provides an uninterrupted thermal barrier for unparalleled performance. However there is an exception. Pa302 1 ceilings with attic spaces n1102 2 1 r402 2 1. So i ll start by saying something that might sound controversial but really isn t.

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. 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. The 2015 irc requires r 49 insulation for ceilings with attic spaces. For the same reason insulation shouldn t touch the roof s underside.

So much information has been devoted to the subject of roof venting that it s easy to become confused and to lose focus. Attic insulation unvented attics must be air sealed at roof deck eaves gables and penetrations. Design the roof to allow full insulation over the top plates of the exterior walls. 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.

Insulation cover should be even and continuous right to the eaves. 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. What is continuous insulation. 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.