Roof flashing is a common component of most buildings, and is most often used around chimney, roof vents, and roof valleys where two slopes meet. Roof flashing can be repaired in most instances in a short time, using basic tools and supplies easily found at any home improvement store. The majority of damage caused to roof flashing is the result of aluminum , copper, or steel that oxidizes or deteriorates and loosens due to age and exposure to the elements. Roof flashing should be inspected annually for problems; a small amount of preventative maintenance can save big problems down the road for a homeowner.
Roof flashing around chimneys are probably the most difficult repairs to make, mostly because the surface area is larger than other areas that utilize flashing. Chimney flashing usually consists of two parts - a base that extends to where it meets the shingles, and a cap that covers the base and is attached to the chimney itself. Most commonly, the flashing cap becomes displaced from the chimney and requires reattachment. This can be accomplished by chiseling out old mortar between the flashing and the chimney, and cleaning the area thoroughly. Using a sponge or paint brush, wet the flashing with water and apply a moderate amount of mortar cement. Press the flashing back into place gently until a bond is created. After allowing the mortar to dry completely, apply a liberal amount of roof sealant to the edges of the roof flashing, and the job is complete.
The roof flashing around vent pipes is also usually in two separate pieces, consisting of a collar that encompasses the pipe and a base. After ensuring that the collar is flat against the base, it is a simple task to apply roof sealant to the base and around the pipe to form a tight seal.
In roof valleys where two slopes converge, it is a common practice to line them with flashing. In situations where the flashing has a hole in it, a basic patch can be made by cutting a new piece of flashing to a size slightly larger than the hole and attaching it in place with the heavy use of roofing sealant. If this type of flashing repair is made, be certain not to create a raised area that will impede water flow. This can cause water to back up and create problems in other areas of the roof due to poor drainage.
A homeowner that has an excessively steep-pitched roof or one that is unfamiliar with roofing safety procedures is best served by obtaining a professional to make roof flashing repairs.
