How to Repair a Damaged Mansard Roof

What You'll Need
Roof Safety Gear
Extension Ladder or Scaffolding
Roof Brackets
Cedar Shakes
Pry Bar
Slaters Ripper
Wooden Block
Corrosion-resistant Nails
Metal Shims
Tin Snips

mansard roof is one of the hardest types of roof to repair. It is composed of two slopes on each side. Because the lower slope is near vertical, this presents a challenge for the do-it-yourselfer. Below are steps on how to repair a mansard roof effectively and safely.

Step 1 – Safety Preparations

Purchase roof safety gear composed of harness, rope and anchor, or you may borrow them individually from friends or neighbors. Next, rent an extension ladder or scaffolding, so you can work safely on the steep slope of a mansard roof. Set the ladder or scaffolding in place.

Step 2 – Assess the Damage

Put on roof safety gear and go up the roof to check for damaged shakes. Inspect every area of the roof to determine which shakes you should replace or repair with metal shims. Cracks in between individual shakes can be repaired by inserting a metal shim underneath it, to prevent water from entering the roof. Badly damaged pieces have to be replaced anew. If there are damaged shakes on the top slope of the mansard roof, install roof brackets for added protection.

Step 3 – Repair with Metal Shims

Collect the tools and place them in a bucket. Knot the rope on the bucket’s handle. Hoist up the tools and materials in small groups. Set them in place where you can reach them easily.

Choose metal shims that are dark-colored and resistant to corrosion. Each piece should be at least 3 inches wide and should be at least half an inch wider on both sides than the exposed crack. Cut the metal shims to size. Slide each one underneath the defective shake ensuring that the lower edge is flush with butts of the surrounding shingles.

To prevent the shim from falling off due to gravity, especially if the damaged piece is located at the lower slope, bend the lower corners each at a 45-degree angle using pliers. The bend should only be small, but just enough to hold on to the underlying cedar shake.

Step 4 – Replace Damaged Shakes

Lift the damaged shake using a pry bar to expose the shaft of the nails. While your assistant is holding the shake firmly, pull the nails off using a slater’s ripper. Pull out the damaged cedar piece. Purchase a cedar shake that matches the color of the existing shingles.

To install the replacement, position it into the vacated spot. The butt should be a half inch lower than the other shingles. Determine where the 2 nails are to be fastened. Drive them both at 45-degree angles into the roof underlayment. To align the new shingle, position a wooden block at the butt and hammer it to drive the shingle upward until it fits flush with the others.

Do the same with the other damaged pieces. Re-inspect the roof for missed damaged areas.