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.

House eleven of the Elmwood project. A new kind of rubber slate is applied to the entire roof.

Ken Langevin from Owens Corning tells Bob about the architectural shingles that have been selected to replace the old roofing material. The shingles are called architectural because they have a three-dimensional look, and they have a 40-year warranty because of the extra build-up of asphalt and mineral granules. Contractors find the shingles are easy to install. The ridge vent comes in a roll. It's rolled out on the ridge and attached with a nail gun. It has a wind driven baffle so any rain that does get in will just sit, and it's covered with the hip and ridge shingle to give it that architectural, three-dimensional look. They also installed an ice and water barrier on the ridge and eaves so that any ice build-up in the gutters won't be able to push up underneath the new shingles.

Bob meets with the President of the Metal Roofing Alliance and demonstrates installation of metal roofing panels.

Bob and Ted look at the Quechee home's standing seam steel roof and then flashback to the installation. For the job the roofing crew basically brought a portable sheet metal shop to the site. The material comes pre-painted in large rolls. It's unrolled into a metal brake that fabricates the individual pieces to the desired length. They are then attached to the roof with clips and screws. Valley sections are individually cut and crimped to fit.

Bob and roofer Paul Morris start by cutting a rough opening in the roof and laying a weather shield. The skylight is mounted into place and the flashing is applied. Bob then assists in laying the new asphalt-shingles.

House seven of the Elmwood project. Homeowner Robert Emanuel has old shingles on the roof and sidewall replaced.

Bob makes his fourth visit to the home in Norwell, Massachusetts, where an addition is being put on a Colonial home. The project has involved the use of insulated concrete forms, also known as ICFs, to construct the shell of the addition. ICFs are essentially foam building blocks that are filled with rebar and concrete to form the walls and the first-floor deck. Next the second floor deck was framed and sheathed with Georgia-Pacific Plytanium DryPly. The roof was sheathed with Georgia-Pacific Plytanium and faced with Deck-Armor as a breathable underlayment over the roof deck. The roof was put on the house in cold weather and there was concern about adhesion between the StormGuard and the roof deck. Deck-Armor eliminates the possibility of frost damage. The StormGuard was placed over the Deck-Armor and nailed into place. Metal roofing was purchased from MetalRoofingWholesalers.com and installed on the addition by a professional. Hal Martin of The Metal Men explains the features of the metal roof being installed. The roof is made of steel with an aluminum mix known as Gavalume. This roofing material offers stronger protection against rust, especially at the ends of the roof line. Galvalume is available in any size up to 40 feet. A ridge cap is put over the top of the installed panels to prevent rain and moisture from getting into the roof cap. Care must be taken installing the Galvalume panels because they are large, unwieldy, can bend and be scratched.

Bob meets with general contractor Richard Marks and roofer Joe Wells to go over the proper installation techniques for a slate roof.

Ryley and Dominic demonstrate installation of architectural grade dimensional asphalt shingles on the Habitat for Humanity Blitz Build house in Yonkers, New York.