How to Replace a Damaged Shingle
Windstorms, a fallen branch or even wild animals can damage asphalt shingles. If you have the confidence to get up on your roof and work there safely, you can replace one or two asphalt shingles with ease. Getting on and off the roof is often the hardest part of the job.
You don’t need expensive tools to replace an asphalt shingle. You don’t need lots of expensive products either. The best part is it usually just takes a few minutes to do the job once you’re on the roof and ready to go.
You can watch a nice short video of me showing how to replace an asphalt shingle by going here:
http://go.askthebuilder.com/replaceshingle
Degree of Difficulty: 
(only because of getting up on the roof)
Step One: Get up onto your roof in such a way as you can safely work on the sloped surface. Some single story houses have steeper roof pitches that permit you to place the extended ladder right on the roof surface so you stand on the ladder rungs while you work. If you do this, be sure the bottom of the ladder is staked off or tied with a rope so the bottom does not kick out while you’re up on the roof.
Step Two: Assemble a hammer and a flat pry or demolition bar that has a 2-inch-wide tip that’s very thin at its end. You’ll need this to pry up the shingle to be replaced as well as the shingle above the damaged shingle. Purchase a caulk tube of asphalt cement and get out your caulking gun.
Step Three: Use the pry bar to lift up the bottom tab surface of the shingle that’s directly above the damaged shingle as well as the tabs of the damaged shingle. Under the lower tab of every shingle you’ll discover a dab of special asphalt cement that welds the shingle tab to the shingle below it. This dab is put on at the factory and helps keep shingles in place during windstorms.
Step Four: It’s best to try to do this repair when the roof temperature is 60 F or less so the sealing asphalt tab breaks loose with ease. This means working in the early morning before the sun hits the roof or when the outside air temperature is just above freezing. Direct sunlight on asphalt shingles can cause the temperature to soar making it very hard to detach the shingles from one another. A hot roof is also dangerous to work on because of dehydration and rapid movements you might make if you touch a scalding hot shingle.
Step Five: When you detach the shingle tabs from above from the damaged shingle and lift it up without breaking the shingle tabs, you’ll see the roofing nails that were installed to hold this shingle in place. You need to remove these nails using the pry bar. Tap the bar with the hammer so it slides under the head of the nail, lift the pry bar and remove and save the nails.
Step Six: You’ll discover that there are at least three other nails that are holding the damaged shingle in place. These nails are the ones holding down the shingle that was installed on top of the shingle you’re trying to replace. These nails penetrate the top edge of the damaged shingle. Lift the tabs of the next higher row of shingles. Carefully remove the nails from these shingles.
Step Seven: Once all the nails are out, the damaged shingle will easily slide out. If you have difficulty, this means you’ve not removed all the nails. Locate the rogue nail or two and remove it/them.
Step Eight: Slide the new replacement shingle into position and hammer in all the nails that you removed. Smear a dab of fresh asphalt cement on the top of each nail head and put a small dab under the shingle tabs you lifted so the shingles lay flat once more.
Summary: The asphalt cement you use from the tube should be used sparingly. More is not always better. If you put it on in cold or cool weather on a light-colored roof, when hot weather arrives, the cement may run out from under the shingles as it’s heated by the sun. This will stain the roof forever.
Column: HT016