Bob flashed back to the installation of the new roof. First the crew removed the old layers of roofing material from the barn. Next they added a layer of Louisiana Pacific oriented strand board (OSB) over the original sheathing. It's manufactured with thin wafers of wood, resins and wax compressed under intense heat. When used as roof sheathing it's extremely resistant to moisture damage. Then they stapled down a layer of felt paper and marked with chalk lines to lay out the courses of asphalt shingles. Since these are double layer shingles, they're fastened along the pre-marked white line to assure that both layers are attached to the roof. Frames for the Velux VSE skylights were installed. These vented skylights will be operated with a hand-held remote. Copper step flashing is added to the side of the skylights and the asphalt roof shingles are fastened up to it.

Bob discusses the advantages of hazard-resistant building techniques pertaining to sheathing the roof with Bryan Readling of the APA, Engineered Wood Association, on the Mt. Pleasant house in South Carolina.

Bob continues framing the affordable home in Mashpee, Massachusetts, with General Contractor Wes Lohr. Lohr begins by squaring the wall, which is done by taking measurements from corner to corner diagonally and checking that they are the same. The crew then snaps a line 36 1/2 inches up from the bottom for the overlapping sheathing that will cover the bottom band and pressure-treated sill. Lohr uses Louisiana Pacific (LP) oriented strand board (OSB) to sheathe the wall. It is treated with a wax coating on one side to protect against weather. LP OSB will not delaminate when wet and is marked with nailing guides to help nailers hit studs every time when studs are properly placed. Any overlapping OSB that blocks window or door openings is cut away, then the wall is raised and eyeballed for placement.