What you need to know before starting
Replacing roof shingles is a task you can do yourself if you have basic carpentry skills, a head for heights, and access to the right tools — but it carries real risks. Falls from roofs cause serious injury. Before you decide to do this work, check whether your roof is under warranty; some manufacturers void coverage if anyone but a licensed roofer does repairs. If you are uncomfortable on a ladder or working at height, or if your roof pitch is steep, hiring a professional is the safer choice.
The actual work involves removing damaged shingles, inspecting the plywood underneath for rot or damage, replacing any compromised wood, and nailing new shingles in place using the correct fastener pattern. The job takes longer than most people expect — a small patch of ten to fifteen shingles typically takes half a day for someone doing it for the first time. Weather matters: you cannot install shingles in rain, and cold temperatures make asphalt shingles brittle and prone to cracking.
Key Takeaways
- Replacing shingles requires removing old nails completely, inspecting the plywood base for rot, and fastening new shingles with four nails per shingle in the correct locations.
- You will need a pry bar, hammer, utility knife, roofing nails, a nail gun (optional but faster), a ladder, and safety equipment including a harness if your roof is steep.
- Work only in dry weather and when temperatures are above 40°F; cold shingles crack easily and wet surfaces are slippery.
- If the plywood under the shingles is soft, discolored, or spongy, that section must be replaced before new shingles go down, which requires cutting out and securing new plywood.
Gathering materials and tools
You will need replacement shingles that match your existing roof in color, weight, and style — bring a sample to the roofing supply store if you are unsure. Asphalt shingles come in bundles; most bundles cover about 33 square feet, so measure your repair area first. Buy one extra bundle in case you make mistakes or need to patch later.
Tools required: a flat pry bar (also called a roofing shovel), a hammer or pneumatic nail gun, roofing nails (typically 1¼ inch galvanized or stainless steel), a utility knife, a tape measure, and a ladder rated for your weight plus 250 pounds. If your roof pitch is 8:12 or steeper, you will also need a roof harness and anchor point. Safety equipment includes work gloves, a dust mask, and eye protection. Wear shoes with good grip — roofing is slippery even when dry.
Removing old shingles and nails
Start by locating all the nails holding the damaged shingles in place. Asphalt shingles are typically fastened with four nails across the top, and the shingles above overlap and nail through the top of the damaged shingle as well. You will need to remove nails from the damaged shingle itself and from the shingle directly above it.
Slide the pry bar under each nail head and lever it out. Work slowly — rushing tears the shingle and damages the plywood underneath. Once all nails are out, peel away the old shingle. If it is stuck down with adhesive (common in hot climates), use the utility knife to cut it free. Remove any remaining nails or nail stubs from the plywood surface; they will puncture new shingles or create weak points.
Inspecting and repairing the plywood base
Once the old shingles are off, look at the plywood underneath. Press on it with your thumb; it should feel hard and solid. If it is soft, spongy, discolored, or has visible mold or mildew, that section is rotted and must be replaced. Rot spreads, and new shingles over rotted wood will fail quickly and may hide ongoing damage.
To replace rotted plywood, mark out the damaged area and use a circular saw to cut it away in a rectangular section. The new plywood should be ½ inch thick (standard roof sheathing) and should fit snugly between the rafters. find it with galvanized or stainless steel screws spaced 6 inches apart around the perimeter and 12 inches apart in the field. Do not use nails for plywood repair; screws hold better and do not back out over time.
Installing new shingles
Slide the first new shingle into place, aligning it with the shingles on either side. The shingle should sit flat with no wrinkles or bubbles. Nail it down with four nails placed ⅝ inch above the shingle's cutout line (the notches at the bottom). Space the nails evenly across the shingle, about 12 inches apart. Drive each nail straight in; angled nails tear the shingle and do not hold as well.
If you are replacing multiple shingles in a row, install them from bottom to top, overlapping each new shingle over the one below it by about 5 inches. Once the new shingles are nailed, nail through the top of the new shingle into the shingle above it (if there is one). This double-fastening is what holds shingles down in wind.
After nailing, lift the tabs of the new shingles and explore roofing cement under them if you are in a high-wind area or a climate with temperature swings. This adhesive helps prevent wind uplift and is especially important in coastal regions or areas prone to storms. Use a caulking gun and explore a dime-sized dab under each tab.
Common mistakes and how to avoid them
The most common error is not removing all the old nails. Nails left behind puncture new shingles and create leaks. Take time to pry out every nail and check the surface by running your hand over it — you should feel no nail heads or stubs.
Another frequent mistake is nailing in the wrong spot. Nails must go through the nailing strip (the area above the cutouts), not through the tabs themselves. Nails in the tabs tear the shingle and do not hold. If you nail too high or too low, pull the nail out and move it to the correct location; do not leave extra holes.
Overdriving nails is also common. The nail head should sit flush with the shingle surface, not crushed into it. If the head sinks below the surface, it can tear the shingle and water can pool around it. If you overdrive a nail, pull it out and use a new one.
When to call a professional roofer
If the plywood damage extends over a large area, if multiple layers of shingles need to come off, or if you discover structural damage to the rafters, stop and call a roofer. These situations are beyond a DIY repair and require professional assessment. Similarly, if your roof has a steep pitch (over 10:12), if you are uncomfortable at heights, or if weather is unpredictable, hiring a professional is the safer and often faster option.
A professional roofer can also identify problems you might miss — ice dam damage, flashing issues, or signs of interior leaks — and address them while the repair is underway. The cost of a small repair (ten to twenty shingles) typically ranges from $150 to $400 depending on your region and roof access, which may be worth the safety and warranty peace of mind.
Frequently Asked Questions
Can I install new shingles over old ones without removing them?
No. New shingles must be nailed to the plywood base, and old shingles in the way prevent proper fastening. Layering shingles also hides damage underneath and creates an uneven surface that shortens the life of the new shingles. Always remove old shingles completely.
What if I hit a nail and it bends instead of coming out?
Pull the bent nail out with the pry bar and discard it. Do not try to straighten and reuse it; bent nails do not hold properly. Use a fresh nail in the correct location.
How long do replacement shingles last?
Asphalt shingles typically last 15 to 25 years depending on climate, ventilation, and maintenance. Shingles in hot, sunny climates age faster than those in cooler regions. If you are replacing only a few shingles on an older roof, the new shingles may outlast the surrounding ones and create a visible color difference.
Do I need to replace shingles if I only see one or two damaged ones?
If only one or two shingles are damaged and the plywood underneath is sound, you can replace just those shingles. If damage is widespread across a section of roof, or if shingles are curling or missing in multiple places, that area of roof is likely near the end of its life and a full replacement may be more cost-effective than repeated repairs.
What should I do with the old shingles after removal?
Old asphalt shingles can often be recycled or disposed of at a local landfill or construction waste facility. Some roofing contractors accept old shingles for recycling. Check with your local waste management facility for options in your area.