Watch Ask This Old House Season 7 Episode 23 Online

General contractor Tom Silva helps a homeowner prepare his concrete basement walls for finished wallboard. Then, up in the loft, plumbing and heating expert Richard Trethewey shows host Kevin O'Connor how to tie a few basic knots. Next, Tom, Kevin and Richard, along with landscaping contractor Roger Cook ask, "What is it?" Then, Roger and certified arborist Matt Foti demonstrate how to care for storm-damaged trees.