How to Replace Missing or Damaged Shingles in 8 StepsRefer to the weather report before you begin. Get the tools and materials you need. Glue the underside of the shingles. If a tile is simply cracked or broken, you don't have to replace it, just repair it.
Start by applying a thick bead of roofing sealant under the crack. Press the tile down and apply a second coat of sealant to the top of the crack. Then spread the sealant with a spatula. To replace damaged roof tiles, you need to remove the damaged tile, install the new one, and seal the edges.
They should be replaced, or cover the roof area, to prevent water damage to the roof support structure and leaks inside. If your roof is more than 20 years old and most shingles are damaged or badly worn, it's time to replace it.