Carpenter Norm Abram shows the new foundation for the kitchen addition to the Manchester, Mass., house, while contractor Tom Silva's crew begins demolition of rotted sections of the sun porch and plumbing-heating expert Richard Trethewey lays out the plan for the pumbing in the master bath. Also: homeowner Kim Whittemore and host Steve Thomas visit a recently renovated house in search of design ideas. On “Ask This Old House,” landscaper Roger Cook looks at ways to sharpen and maintain saws, and Silva fixes a sagging floor during the “Housecall” segment.