Watch Ask This Old House Season 8 Episode 12 Online

Landscaping contractor Roger Cook helps a pair of homeowners improve the appearance of an unsightly concrete retaining wall with wooden lattice and climbing vines. Then Roger, along with plumbing and heating expert Richard Trethewey, general contractor Tom Silva, and host Kevin O'Connor ask, "What is it?" Next, up in the loft, Tom shows Kevin how to flash a newly-installed window properly. Then, Richard helps a homeowner quiet a noisy PVC plumbing vent in her attic.