Steve Thomas, former host of the PBS series This Old House (1989-2003) and Planet Green channel’s Renovation Nation (2007-2009), is used to renovating challenging homes across the nation. However, his most recent project was a bit different for two reasons: it was his own newly purchased, 100-year-old, adobe-style home in downtown Santa Fe, N.M., and it was a mess.

For help, Thomas turned to someone he met while filming in Santa Fe in the 90s: Aaron Lewis with the Santa Fe firm Southwest Spray Foam. Lewis and partner, Matt Segura, immediately got to work on the home’s crumbling roof. They removed layer upon layer of tar, the original roofing small “latillas” (aspen or juniper branches laid across wooden beams) and more than 16 tons of dirt. They cleaned it, did extensive repairs to the roof deck, then used 6 to 12 inches of spray foam insulation (SPF insulation) by NCFI Polyurethanes: the U.S. company that pioneered spray foam insulation in the 60s, and the company that supplied the insulation for the This Old House episode in the 90s.