Table of Contents
Materials and Tools
- Asphalt Shingles (make sure to get a good color!)
- Starter Shingles
- Roofing Nails
- Work Gloves
- Utility Knife
- Tin Snips
- Flashing (valley, vent, step, and dormer)
- Felt and waterproof underlayment
- Drip Edge
Even though it is possible to install new shingles on top of existing ones, it is best to remove the current ones first. It is not that hard to do, but there are some things that make it much easier.
First, it is best to start at the peak because these shingles won’t be under other ones. Then, work your way down the roof. A small shovel works to pry off the shingles, but other tools work too. Be careful, but you can try different tools to find out what works best for you.
Work your way from the peak down to the edge before moving over to the next shingles. It also is easier if you can get the shovel, or other tool, under the underlayment. This will make it easier to rip off larger sections of shingle at once.
Now it is a good idea to evaluate the flashing. Flashing is thin metal, or other material, that directs water away from your home. Inspect it for dents, cracks, and rust. If it looks good, you can reuse it with your new shingles. However, flashing is really important so if there are any signs of wear, remove and replace it.
To remove shingles underneath the flashing you are reusing, just remove the nails first. Then you can slightly bend it to slide the shingles out.
It is best to replace the flashing around vents and chimneys even if you are reusing the other flashing. Remove this flashing after every shingle has been removed.
When removing shingles, don’t worry about nails that don’t come up. You can remove them after you remove the shingles. This will make the process go quicker.
Drip edge isn’t always required, but it is a good idea to install it anyway. Just fasten the drip edge on the edges of the roof and over the fascia. The fascia is the band that you can see below the roof edge.
Use roofing nails every 2 ft to secure the drip edge. It is also good to install additional drip edge on the gable ends after you place the underlayment. You can use tin snips to cut the drip edge to size. Overlap drip edge 1 to 2 inches.
Underlayment is important. It is the last defense against intruding water. Peel-and-stick underlayment is an easy choice.
Roll on the underlayment in strips working your way up towards the peak. Each row should overlap the previous. Try to overlap at least 2 inches. Peel-and-stick underlayment has a sticky backing after you peel off the plastic. This will make it easy to stick the overlapping piece down.
It can help to nail down the end and then the rolling will be easier. Always make sure underlayment will seal out all water before moving on.
It is a good idea to put on two layers of underlayment. Be sure to install the second layer directly over the first so that the edges line up.
Flashing should be installed over the underlayment. Make sure you install flashing in every valley because they cause potential pooling. Valley flashing is simple to install. Just make sure it is secure and prevents water from getting to the underlayment that is beneath it.
Also install valley flashing over all the peaks for extra protection. It should fold over and be secured with roofing nails.
Starter shingles add extra protection for the eaves and rake edges on your roof. They will also prevent shingles from blowing off during heavy winds. Since shingles can’t be overlapped in these areas, starter shingles are installed.
Starter shingles should be installed so that the adhesive part is near the button and facing upwards. Nails should be 2 to 3 inches away from the bottom of the eave.
Overlap the starter shingles ¾ inch past the drip edge. Use the nails 2 to 3 inches away from the eave. It is good to use about 5 nails. The adhesive strip on starter shingles will seal with the shingle that is installed above it. This will prevent wind from getting up under your shingles.
It is always good to install one shingle first to use as a guide. Place it so that the bottom edge aligns with the bottom edge of the starter shingle. It can make it easier to draw a line with chalk from this first shingle. This helps to perfectly align the shingles from here on.
Work you way across with each row and then do the row directly above it. Stagger the seams as you move along. The manufacturer should have a recommended pattern. Hammer nails in about 2 inches from the end of the shingles.
When you get to the edge of the roof, overlap it and then cut the shingle to size. For peaks, bend the shingle over and then nail the other side down. Use four nails for each shingle or six if the area is prone to heavy wind.
With the second row on, you will have to cover the previous row by 5 to 6 inches. You can also use a chalk line to make it easier to line up each row.
When you get within 9 or so feet from the ridge or peak, measure to your shingles at the end of the rows on both sides. If one side is closer than the other, mark where the next rows will go all the way to the top. Make up the difference by overlapping a little more with each row. This will make the final overlap at the ridge or peak uniform.
The pitch of your roof, the brand of shingle, and the weather in your area all determine the number of nails to use. It also changed the best location to insert the nails. Most shingles use 4 to 6 nails, but it is good to double check. Nails should be long enough to penetrate the wood by at least ¾ inch. Professional roofers use 1-¼ in roofing nails (usually zinc-coated).
Always nail straight into the shingle so that they are pulled flat against the decking. If a nail isn’t fully driven in, use a hammer to fix it.
When you get to a ridge or peak, wrap the shingle over the top. Run shingles through valleys and over rakes and raidges. Finally, when all shingles are attached, you can do final trimming for aesthetics.
When you get to vents and other obstructions, keep installing shingles the way you were, but cut them to fit closely around the obstacles. Then, you will put vent flashing around them before adding more shingles on top.
Step and Dormer Flashing
Whenever you get to a wall or chimney, you will have to install flashing. Install the shingles so that they are flush against the wall. Then, you will nail the dormer flashing to the shingle and the wall.
Make a small one to two inch cut at the bend in the first step flashing. Run step flashing past the dormer flashing and bend it around the corner. It may take a hammer, but it should bend onto the dormer flashing.
Now, the shingles will cover the flashing. You will do this as you make your way up the roof. Each piece of step flashing should overlap the previous one. It is best to install the step flashing after the initial shingles cover the area.
There is one more step before you finally seal the shingles. You need to peak the roof. This is simple, but important. This is just an additional row of overlapping shingles bent over the peaks of the roof.
Finally, you will seal the shingles and finish the project. Sweep away any debris and then seal all visible nails. There are different types of sealants for roofs, so pick one that suits both your budget and your needs.