How to Put Shingles Over Existing Shingles

How to Put Shingles Over Existing Shingles. Installing new shingles over a current layer can save you the task of removing the old layer from the roof. This is a procedure, however, that must be done precisely. Your new shingles need to completely cover and seal off all of the roof's first layer. The new layer of shingles will provide an extra layer of protection to the roof if done correctly. If not, the roof will develop leaks in many areas.

New shingles can improve the house's appearance and protection.

Things Needed

  • Pry bar
  • Claw hammer
  • Push broom
  • Shingles
  • Utility knife
  • Flashing
  • Roofing cement
  • Nail gun


Step 1

Pry the triangular ridge caps off the top of the roof using a flat pry bar and pull out all the nails.

Step 2

Unscrew and remove all air vents and pipe flashings mounted to the roof using a screwdriver or wrench.

Step 3

Glue down back into place any broken pieces of the old shingles with roofing cement to ensure as flat a surface as possible. Cut small pieces of new shingle material and fit them into any holes if needed.

Step 4

Clean off all debris from the roof using a wide push broom.

Step 5

Nail the steel drip-edge flashing to the edge of the roof, installing the eave piece and then the rake piece on top of the eave piece. Place the nails at the bottom ends of the current shingles.


Step 1

Cut "starter strips" of shingles, cutting the strips so they'll just cover the exposed bottom shingles on the roof, and then nail the starter strips to the bottom edge of the roof; place the nails along the top of these strips.

Step 2

Cut the first full length of shingles so they go from the bottom of the roof to the bottom edge of the third layer of existing shingles and cover that area of the roof with them. Place the nails above the vertical "tab slots."

Step 3

Add each subsequent layer of full shingles so they line up against the currently exposed bottom edge of the original layer. Make sure none of the new shingles' "tab slots" line up with the old shingles' slots.

Step 4

Cut a sheet of shingles into ridge caps after covering both sides of the roof with shingles, then nail the ridge caps to the crest of the roof.


  • Install any pipe or vent flashing pieces right after you surround the pipe with shingles, applying roofing cement so the flashing sticks. Make sure the flashing's bottom edge covers the shingles but the shingles cover the flashing's top edge.


  • DIY Advice: Roofing Over Existing Shingles