Roger installs a new front walk in a running bond pattern. Tom runs a custom profile for the chair rail and both copes and miters the corners as it is installed. Interior designer Christine Tuttle makes tile selections at a local showroom. Norm and Tom work to fit a new four-panel interior door into an old doorjamb. As the cabinet installation finishes up, kitchen designer Steve Jackowski offers a preview of the countertops, tile and striking copper vent hood that are on their way to the kitchen. In the second half of the hour, on ASK THIS OLD HOUSE, Richard helps a homeowner replace a shower valve that shuts off mysteriously. Tom shows how to patch a hole in baseboard. Roger shares some tips for maintaining a lawn mower. And the guys ask, "What is it?"