How to Fix a Leaky Garage Roof

Leaks in a garage roof are not only annoying, but can be very expensive. Quick repairs are necessary to avoid structural damage to the garage. The cost of repairs can skyrocket if it is an attached garage. Ignoring the problem could result in the need for a total roof replacement. A little roofing cement and a ladder are the main ingredients of this important roof repair.

Removing the Leaky Shingle

A shingled garage roof.
  1. Locate the leaking shingle and use a pry bar to remove the nails holding it in place. It is generally two nails on each end, towards the top. Pull the bad shingle out from beneath the layer above it.

  2. Paint a thin layer of roofing cement over the exposed space between shingles. Slip the new shingle up into place and fasten with two roofing nails.

  3. Apply a layer of roofing cement over the nails. This prevents leaks through the holes.

How to Fix a Leaky Flat Garage Roof

  1. Use a broom or brush to remove any rocks or debris from the leaking area of the roof. The entire roof needs cleared of debris periodically to avoid puncture damages.

  2. Check for deeper structural damage inside of any visible holes. Leaks can rot the wood beneath the surface. Damaged wood needs replaced before patching the leak.

  3. Fill the smaller holes with roofing cement. Extend the cement out roughly 3 or 4 inches from the actual repaired hole. Cover larger holes with a layer of roofing felt and attach to the roof with a few roofing nails. Cover the entire patched area with roofing cement.


  • Wear shoes with heels that grip when on the roof. Use caution when climbing up and down ladders.