Transforming a backyard; dripping bathroom fan

Landscape contractor Roger Cook helps a young couple transform their muddy backyard into a low-maintenance play area for their two children to enjoy. In the ASK THIS OLD HOUSE loft, plumbing and heating expert Richard Trethewey shows host Kevin O'Connor several types of portable space heaters and offers suggestions on how to choose the right one. Roger, Kevin and Richard are joined by general contractor Tom Silva to ask, "What is it?" Later, Tom makes a HOUSE call to help a homeowner who is having problems with a bathroom fan that drips water down into the room below.