A leaky porch roof is caused by numerous reasons, but it is most probably due to damage in the flashing and not the roofing material unless the roofing material is too old and nearing the end of its life. Cracks in the shingles can also be the culprit especially if the shingles are underneath a tree branch.
Step 1 – Determine the Location and Cause of the Leak
If the leak is dripping down just right in front of the house, then there is a problem with the flashing connecting the roof to the exterior walls of the house. This flashing has two sides – one connected just on top of the porch roof and the other to the exterior wall. Find out if the flashing is correctly installed and sealed or if it has holes caused by corrosion.
If the leak is dripping in the middle of the roof, go to the top of the roof and check if some of the shingles are cracked. If the shingles are still in good condition, a repair or a shingle replacement is a good option.
Step 2 – Repairing Damaged Flashing
If the flashing has holes in it probably caused by corrosion, clean the surroundings of the hole or holes to get rid of the rust. If the holes are small, they can be repaired by putting a small bead of silicone to cover them. To prevent further corrosion, it is probably best to coat the flashing with rust protection coating or paint.
If the flashing is severely damaged by corrosion, it is best to replace it with a new one. Make sure that the flashing is made of a material that's not easily corroded. Aluminum is the easiest to install, but copper flashing provides the best quality. If the metal is susceptible to corrosion, make sure to coat it with a protective finish.
Step 3 – Repairing the Shingles
If any of the shingles are cracked or damaged, determine if they need to be replaced or if they can be repaired. Small cracks in the shingles can be repaired through the use of a sealant. But severely damaged shingles should be replaced with new ones. Cracks in the shingles allow water to penetrate the roof and cause it to leak. Find the cracked shingles and pry them with a flat pry bar to expose the underside. Apply a good amount of sealant on the underside of the crack and attach it to the roof. The sealant should prevent water from entering again. For heavily damaged shingles, remove them and install new ones instead.
Step 4 – Installing Gutters
While water dripping off the edge of the porch roof may not be considered a leak, it causes water to fall into unwanted areas. To remedy the problem, install gutters on the edges of the roof and direct the water into drainage or canal. This will be very helpful in preventing the porch from flooding during heavy rainfall.