This Old House general contractor Tom Silva helps a homeowner install a rain gutter, downspout, and rain barrel. (See below for a shopping list, tools, and steps.) SUBSCRIBE to This Old House: http://bit.ly/SubscribeThisOldHouse Shopping List for Installing a Rain Gutter: - Aluminum gutter - Aluminum downspout - Aluminum elbows, end caps, mounting straps, and downspout…