The Carlisle, Mass., farmstead project continues with masonry work around the barn fireplace. Meanwhile, interior decorator Alexa Hampton shops for granite countertops and host Kevin O'Connor mulls interior color schemes with painters. And underneath it all, the well contractor finds water---700 feet down. On “Ask This Old House,” contractor Tom Silva helps an Illinois homeowner replace a window on an exterior door, and landscaper Roger Cook helps a Massachusetts homeowner prune a pin-oak tree.