Tips for watering lawns; building a bookcase

In the ASK THIS OLD HOUSE loft, plumbing and heating expert Richard Trethewey shows host Kevin O'Connor how to replace all of the parts inside a typical toilet tank. Landscape contractor Roger Cook and Kevin head outside to look at different types of above-ground sprinklers, and Roger shares basic tips on how to water a lawn. Back in the loft, general contractor Tom Silva shows Kevin how to build a simple but elegant bookcase using plywood and portable power tools.