Flashing is a good way of preventing water from entering a dwelling at the point where the roof meets the walls. To begin the installation, fold a five-by-seven piece of aluminum flashing lengthwise.

Although it’s been around for centuries, metal roofing has become increasingly popular in the last 20 years. Metal roofs come without the usual mess and cleanup that comes with asphalt-type products.

Q: I need to install a deck ledger board against a house with wood lap siding. Soon I’ll be doing the same on a brick home. What is the proper way to install flashing so I don’t get any leaks where ...