How to Install Exterior Rigid Foam, Part 2

On the second layer, offset and tape the seams, and use the rainscreen strapping to hold everything in place

October 07, 2016
installing rigid foam insulation on home exterior

All photos: courtesy Dan Morrison

Last fall, remodeler David Joyce, owner of Synergy Construction, in Lancaster, Mass., and his crew performed a deep energy retrofit and gut rehab on a home in Concord. To boost the envelope’s R-value, they added 4 inches of polyisocyanurate foam in two 2-inch layers to the walls and roof. In Part 1, we looked at details in the first layer of wall foam, which was installed over the existing T1-11 siding. Here in Part 2, we focus on the installation of the second layer of foam as well as strapping for the rainscreen siding assembly. To watch videos of the complete process, click here.

This article is adapted from a video originally produced for and published on Many thanks to Synergy Construction’s David Joyce, Calvin Cutts, Damien Higgins, and Patrick Burke for loaning us their jobsite.

About the Author

Sal Alfano is Director of Content for Professional, 202.603.4884

About the Author

Dan Morrison is senior technical editor of, a sister site to Professional Remodeler.

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