Replacing damaged or missing asphalt shingles is a simple task, as long as the roof is not too steep and you do not harbor a deep fear of heights.
Step 1: Safe access to the roof is imperative. Wear rubber-soled shoes to avoid slipping and angle the ladder 1 foot out from the structure for every 4 feet of ladder height. Be certain the ladder footings are on level ground.
Step 2: Once you have safe access to the damaged shingle, use a pry bar or putty knife to separate and lift not only the damaged shingle, but also the two undamaged rows directly above the shingle to be replaced.
Step 3: Shingles overlap each other to protect the nail holes from the elements. Lift the shingle two rows above the one to be replaced and carefully remove the nails along the middle of the good shingle overlapping the damaged one.
Step 4: Next, lift the shingle whose nails you just removed and pull out the nails located across the middle of the damaged shingle.
Step 5: Remove the damaged shingle. Clear away any dirt or debris. Be careful not to damage the surrounding shingles or underlying roof felt.
Step 6: Apply a small amount of roof tar to all of the empty nail holes.
Step 7: Slide the new shingle into place and hammer in a row of appropriately sized galvanized roofing nails along the center of the shingle. These nails should extend through the new shingle and into the top of the shingle directly below it.
Step 8: Apply a small amount of roof tar to the tops of each of the new nail holes and to the underside of the new shingle’s tabs.
Step 9: Smooth the shingle into place. Reposition the older shingle directly above it.
Step 10: Dab a bit of roof tar into the empty nail holes on the older shingle. If possible, use the same nail holes and hammer in a row of nails along the middle of the older shingle. Apply roof tar to those nail heads and to the underside of that shingle’s tabs also.
Step 11: Apply roof tar to the underside of the shingle tabs overlapping the older shingle and to the underside of any other loose shingle tabs in the surrounding area.