BASC Search | Building America Solution Center

Unvented roof assembly at rake retrofitted with spray foam installed along the underside of the roof deck and extended to the rake edge to insulate and air seal the attic

Image

Vented roof assembly at eave retrofitted with rigid foam, spray foam, and fully adhered membrane to air seal the top of wall-to-roof transition

Image

Retrofit of cantilevered wall showing details at the outside corner for installing air sealing and rigid foam insulation in the wall and closed-cell spray foam in the overhanging floor

Image

Seal the drywall to top-plate seams and the lower edge of baffles to the top plate to prevent the air coming from soffit vents from flowing under baffles into insulation.

Image

Rigid foam insulating sheathing installed over an existing garage ceiling with retrofits to air seal exterior wall before adding exterior wall insulating sheathing

Image

Form an insulation dam of sheet metal around a flue pipe in the attic after air sealing around the pipe with sheet metal and fire-rated caulk or canned foam

Image

Right – Fiberglass batt insulation fills the walls while the floor joists above are insulated with spray foam insulation to both insulate and air seal this transition space.

Image

Retrofit of cantilevered wall with beam showing details at the outside corner for installing air sealing and rigid foam insulation plus water control membrane in the wall and overhanging floor

Image

Side view showing air-sealing and rigid foam insulation is installed over existing wall and ceiling under a room above, then covered with new gypsum board.

Image

Roofing paper protects the top of the new plywood parapet while the base of the parapet is air sealed with spray foam and fibrous insulation is installed in the rafter cavities in this flat roof retrofit

Image

Side view showing how the existing garage wall and ceiling are air-sealed prior to installing rigid foam insulation on the garage side of the shared wall of an existing home.

Image

Right – Structural insulated sheathing can provide racking strength (lateral load resistance), and serve as an air barrier and thermal barrier if installed according to manufacturer’s specifications with taped, sealed seams

Image

Form an insulation dam of heat-resistant insulation with at least 3 inches of clearance around a flue pipe in the attic after air sealing around the pipe with sheet metal and fire-rated caulk or canned foam

Image

Right- This flue pipe has been air sealed with sheet metal and fire-rated caulk and an insulation dam has been constructed to keep insulation from touching the hot flue pipe

Image

Right – Spray foam air seals and insulates the walls including the walls behind the fireplace and covers the underside of the roof deck of this mixed-dry climate home to provide an insulated attic space for HVAC ducts.

Image

Right - Reduce condensation risks to blanket insulation by installing perforated vapor retarder covered fiberglass blankets over rigid foam that is air-sealed at all edges; staple the blanket to nailers and top/bottom plates and tape over the seams.

Image

Plan view (from above) showing how the existing garage wall gypsum board is cut away to air-seal the shared wall before adding rigid foam insulation on the garage and exterior walls of the home.

Image

Right – The window header is filled with spray foam and sealant is used to air seal wood-to-wood seams; however, it would be preferable to design the wall to avoid so many stacked studs around the windows because they prevent wall insulation installation.

Image

Sealed Attics?

Reference

Article describing how insulating and air sealing unfinished attic spaces can lead to reduced energy bills in some homes.

Why Seal and Insulate?

Reference

Introductory guide to air sealing the envelope of a home to reduce wasted energy and save on energy costs.

Sealed and Insulated Flex Ducts

Video

Video describing how to seal and insulate flex ducts.

Sealed and Insulated Flex Ducts

Guide

Guide describing how to air seal and insulate flex ducts.

Sealing the vent area insulation

Image

Right – Duct register is mastic sealed to framing

Image

Right – Metal duct boot is properly sealed at seams

Image

Right – Flex duct is mastic sealed at junction box

Image

Right – Metal or fiberboard duct is mastic sealed at seams

Image

A Do-It-Yourself Guide to Sealing and Insulating with Energy Star

Reference

Guide for homeowners describing how to find and seal basement and attic air leaks, determine if attic insulation is adequate, make improvements safely, and reduce energy bills.

Right – Closed-cell spray foam seals the wall cavities.

Image

Selecting Healthy Insulation and Air Sealants

Presentation

Webinar from Rebecca Stamm of Healthy Building Network and Roberto Valle of HomeFree describing policies surrounding environmental and human health impacts of insulation and air sealing materials. Free EEBA login required.