How to Replace Roof Decking That has Rotted

Decking covers the rafters or truss atop a house and supports the shingles. Because decking is a wood or wood-base product, it is susceptible to rot when exposed to water because of damaged or poorly installed shingles. Although you can spot rotten decking from the ground, you must climb onto the roof to replace it. Replacing decking requires basic carpentry skill and tools. In fact, the most challenging aspect of replacing decking is climbing onto the roof itself.

Tape measure
Hammer
Framing nails
Roofing nails
Roofing felt
Plywood
Shingles

Instructions

- 1
  Climb onto the roof to survey the rotted decking. Look for holes, missing shingles and sunken areas.
- 2
  Rip the shingles from the rotted areas by hand or with a scraper if the area is large. Cut a square around the rotted area. The square should extend to the center of the next rafter or truss beyond the rotted area. Be careful not to cut through the rafters or trusses. Toss the shingles and decking off the roof. Drive any leftover nails into the rafters or trusses
- 3
  Measure the length and width of the cutout. Cut a piece to fit from plywood.
- 4
  Place the plywood over the opening and nail it to the rafters or trusses with framing nails.
- 5
  Cover the new decking with roof felt and nail the felt in place with roofing nails.
- 6
  Place a shingle so the bottom half overlaps the top half of the shingle directly below it. Nail the new shingle in place with roofing nails. Overlap the shingle with a new shingle and nail the new shingle to the decking. Repeat until the repaired area is covered with shingle.

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