How to Replace Roof Shingles?

A total roof replacement, though sometimes necessary, is an expensive and significant home project, so routine care and maintenance of your roof is key in minimizing extensive damage or stopping the spread of existing damage. The main way to ensure your roof’s integrity is to keep your shingles in tip-top shape, so today we’re focusing on the DIY process for asphalt shingle replacement.
Man Replacing roof shingles

When to Replace Roof Shingles?

How can you tell if a shingle needs replacing? The main indicators of shingles in need of attention are:

  • Cracks or tearing – If it’s a small crack, you can reseal it with roofing sealant, but larger cracks or tears will require repair/replacement
  • Missing chunks – if a chunk of the shingle is missing, the entire strip will need to be replaced
  • Whole Strips are missing – Get up there and get some shingles on your roof ASAP!

Damaged Asphalt Roof Shingles
If your area has recently experienced a significant weather event, or your roof is older, you could see any of these issues on the top of your home. To minimize subsequent damage, they should be dealt with as soon as you’re able to tackle the project.

Can you Replace Individual Shingles?

For asphalt roofs, “individual” most accurately refers to a 3-strip. Common asphalt shingles are manufactured in such a way that when installed, it appears that every shingle on the roof has been installed singularly.

In reality, general-use shingles are manufactured to have 3 regularly spaced tabs on the lower half of a strip, and an asphalt-coated fiberglass mat on the upper half. This mat is used to anchor the shingle strip, provide additional elemental protection, and ensure a cohesive visual and practical finish for your home.

Because of this, it’s unlikely that you’d replace just a single tab if there is damage, but instead, you would remove and replace the entire strip to maintain the integrity of the surrounding roof area.

If you’re lucky, the contractor who did your roof replacement or who initially installed the roof (on newer homes) left behind a few packs of shingles in case of future need. However, if you’re unlucky, you’ll need to purchase a pack at your local home improvement store. Make sure to take measurements of the existing shingles before heading out, and attempt to purchase a replacement that is close to the existing size and color to make the patch less noticeable.

Once you have your replacement shingles on hand, it’s time to get started!

How to Replace Missing Shingles?

Before climbing up on your roof, grab the following hand tools and materials.

Tools Needed

  • Small Pry Bar
  • Hammer or Roofing Nailer
  • Utility Knife
  • 1 ¼” Roofing Nails
  • A Tube of Roofing Sealant and a Caulk Gun
  • Work belt or pouch
  • Shingle Strip
  • Ladder (unless your home has a window or balcony with easy roof access)

Replacement Instructions

The video below explains the step-by-step process of removing and damaged shingle and replacing it with a new one.

  1. Set up your ladder, making sure it’s at a safe pitch against the roof and with solid footing. Bring all materials up onto the roof in the area you’ll be working on before beginning. Take multiple trips if needed, be safe!
  2. The nails holding down the shingle you’ll be removing will be hidden underneath the shingles above it. Try and find the start and finish of the complete strip by prying up the surrounding finish. You don’t want to cut out just a section of a shingle strip and instead should aim to remove the full strip, even if only a portion of it is damaged.
  3. Use your pry bar (with light hammer taps if needed) to break any seal and gently lift up the row above, removing nails as you go. There will be nails visible along the tar line, but there will also be nails along the top of the strip. To remove those nails, you’ll need to pry and lift up the shingles two rows up from the strip needing replacement. Depending on the manufacturer, you’ll remove about 4-6 nails.
  4. Once all the nails have been removed, the shingle strip should slide out easily. If it doesn’t, you haven’t removed all the nails. Figure out where the strip is stuck, and make sure you remove the nails. Don’t just yank it out – you could damage the nearby shingles and potentially cause leaks in your roof.
  5. Now that the old strip is out, dry-fit the replacement strip. If you had leftover original shingles on hand, the new strip should slide right in. If you had to purchase a different kind, you may need to trim it down slightly with your utility knife to fit. Use a straight cutting edge if possible, and don’t cut on top of the roof, as you could potentially damage the shingles beneath!
  6. Hold up the shingles in the row above the new strip to nail it in. You want to make sure that you’re nailing in the same line that you removed the initial nails from (though not into the same holes, of course). Make sure that the new nail holes will be covered by the shingle row above once they’re again laid flat.
  7. Repeat with the top of the strip, two rows up from your replacement shingle row.
  8. Once the new strip is in and secured, secure each shingle that was manipulated during the replacement process. Place a dime-sized dab of roofing sealant on the corner of each shingle tab, and press down gently. Within a few days of exposure to heat and sunshine, all the shingles will once again be flat and secure. Some contractors suggest using a brick or other weight for 24 hours to ensure a tight seal, but it isn’t required.
  9. Clean up the area and remove your tools from the roof. Check on your work after a week or so, just to make sure all is well!

Frequently Asked Questions

Do I need a permit to replace shingles?

If you’re following the steps above to complete a minor repair, you don’t need a permit, as that’s considered routine maintenance. However, if you’re replacing a larger area of the roof, even if it isn’t the full roof, you’ll need a permit as that’s considered reroofing. To be sure, just check in with your local building department to determine what constitutes a “large area” to make sure you’re in compliance.

Can I just put new shingles over the old ones?

That depends. Short answer- with asphalt shingles, yes. Any other shingle type- no.

However, it’s recommended to remove and replace whenever possible, rather than installing on top of existing shingles.

Never mix shingle types. For example, if you have degraded or rotting cedar shingles and are replacing the whole roof with asphalt, you should not install the asphalt over the cedar, as it will continue to degrade and affect your roof decking over time.

You also cannot install new cedar over old cedar, or new slate over old slate. Asphalt is the only shingle type, where installing over another layer is feasible; though again, it isn’t recommended.

Can I replace shingles in winter?

Roofing companies are operational all year round, and professional tradesfolk have the equipment and skills to install a new roof in any season. However, installation is easier spring through fall, and the DIY-er will likely find the task more approachable in friendlier temperatures.

Safety and Final Tips

  • Be safe – a warm, dry day in the late morning or the afternoon is best for executing a shingle replacement. You want clear visibility and no threat of rain while your roof decking is exposed, and no slickness on the surface of the roof from morning dew or precipitation as you’re working. This keeps you safe up there and makes the task quicker and easier.
  • Shingles can snap or bend in very cold weather, so if you’re repairing them in winter, be extra gentle with the manipulation of your shingles.

To that point, you can definitely tear shingles with a pry bar, so go easy as you’re working so you don’t make your project bigger than it needs to be.