Pro and Con: Lead Roof Flashing

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Lead roof flashing has many advantages and disadvantages when it comes to sealing a roof against leaks. When a roof meets a vertical surface, such as the wall of a house, the joint between the two has to be sealed with some flashing. The properties of lead make it a very favorable building material but there are many factors that also act against its current popularity.


Lead is used because it is one of the most durable metals that exists. Lead can expand and contract with varying temperatures, meaning that it can adapt to maintain the efficiency of your installed flashing. It is perfect to use on houses that are open to a variety of elements and different atmospheric temperatures. This means that during an intense summer or cold winter, there will be no need to call a repairman in for cracks or melting.


Lead can be molded into a variety of shapes to suit different types of flashing design. It can be adapted so that it will fit along the edge of many different types of roofs. It will not catch fire, which can be important during an intense lightning storm. It will also not buckle unless it is subjected to very high temperatures that would not be seen in a habitable environment.


Lead is a great barrier to many things. It is resistant to atmospheric corrosion which means it will last longer than other types of flashing. It is also sound resistant, making a home slightly quieter, and radiation-resistant, which is important to the structural integrity of a house. It is also a well-recognized form of insulation that, despite flashing position, will prevent heat from leaving your home.


This metal can be crafted to give the outer rim of a roof a pleasant finish. Lead is not the ugliest of metals to behold. Lead in flashing will be reduced from a shiny, natural state into a refined and professional-looking material.


Lead is a very toxic metal that can poison a liquid substance such as water. Over time, it will break down and could pollute the water that is accumulated through lead flashing. The lead contained in the flashing can start to flake if it is not maintained. This water can be diverted off into other natural habitats that may rely on it.


Lead has been used for a variety of building methods over hundreds of years. Lead supplies are lower than they have ever been and this has driven the cost of lead up. More and more lead is being bought by the battery and electronics industries, which makes it more expensive in the construction world. Estimates put current supplies left at under 50 years.


Lead is not the lightest of roof flashing materials. Although there is a good argument to use it, lead flashing places extra stress on the gutters and roofline of any house. If the lead flashing is not installed perfectly, it can widen cracks in the foundations of a home because of its density and weight.