Fixing squeaky stairs and installing an automatic shut-off valve for the washing machine.

General contractor Tom Silva gives some lucky homeowners a little peace and quiet when he stops by to fix their squeaky stairs, and also lends a hand to replace a broken baluster. Then Tom, plumbing and heating expert Richard Trethewey, landscape contractor Roger Cook and host Kevin O'Connor ask, "What is it?" in the ASK THIS OLD HOUSE loft. Later, Richard helps a homeowner prevent a flood -   and costly water damage - by installing an automatic shut-off valve for her washing machine.