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How to Build a Gable Roof

Gable roofs are so common on homes because they look good, work well, and are not complicated to build. You should definitely consider learning how to build a gable roof a two-person job. Your partner will help you lift boards into place and hold them steady while you nail them.

How to Build a Gable Roof Step by Step

  1. Decide the pitch of your roof. A typical gable roof rises 3 to 12 inches for every 1 foot of horizontal space.
  2. Use an online roof pitch calculator to obtain the rafter length for the pitch that you desire.
  3. When shopping for lumber, select the straightest 2×6 boards that you can find for the ridge board.
  4. After obtaining enough 2x4s and 2x6s to build the roof, begin by building the top plate.
  5. The width of the top of the wall determines whether you build the top plate from 2x4s or 2x6s.
  6. Nail two layers of boards along the top of the walls where the rafters will set.
  7. Offset the seams of 2x4s or 2x6s by at least 24 inches as you build the top plate.
  8. Attach top plate boards with 8-penny nails.
  9. Working along the top plates, make marks every 24 inches for placement of ceiling joists.
  10. Cut 2×4 joists the width of the building beneath where the gable roof will rise.
  11. Center each joist over the marks on the top plates.
  12. Position joists so that they are flush with the outer edges of the top plate.
  13. Nail them in place with construction nails.
  14. At this point in the how to build a gable roof directions, you must cut the rafters.
  15. Refer to the rafter length determined according to the roof pitch you chose.
  16. If you want the roof to overhang at the eave, add that to the length of the rafters.
  17. Mark the angle for the top cut of the rafter with a framing square.
  18. Cut on the line with a circular saw or miter saw.
  19. On the other end of the rafters, mark where the rafter will sit on the top plate.
  20. Use the framing square to mark a triangle for the seat cut.
  21. Your overhang amount will be beyond the seat cut.
  22. Saw out the triangles to complete the seat cut notches.
  23. Ask your partner to hold a rafter at the corner with the seat cut against the top plate.
  24. Measure from the top of the rafter to the bottom of the top plate.
  25. Cut 2x4s this length to use as rafter supports while you continue with how to build a gable roof.
  26. Line up a support board with the edge of the rafter and nail it to the top plate.
  27. Insert another support board 2 inches away from the first.
  28. Build supports for the rafters on each side of the roof.
  29. Position the supports flush with the rafter and clamp them together.
  30. Place hurricane clips along both sides of the rafter at the seat cut and top plate.
  31. Make sure the rafters fit snugly against the top plates.
  32. Drive 1-1/2 inch nails through the hurricane clips into the lumber.
  33. After attaching the end rafters to the top plates, move on to building the ridge board.
  34. If a single 2×6 is not long enough for the whole roof, connect multiple 2x6s. Always have the seams meet at rafters.
  35. Drive 8-penny nails through the end rafters into the ridge board.
  36. Align the rest of the rafters with the ridge board.
  37. Use a level as you go to ensure that you get a straight roof line.
  38. Nail the rafters at an angle into the ridge board.
  39. Nail in the rest of the rafters to the top plate and ridge board.
  40. To build roof decking, line up a 1/2-inch plywood board at a lower corner of the roof.
  41. Nail it to the rafters.
  42. Fill in the rest of the roof with plywood. You are now ready to apply underlayment and shingles.

Tools & Materials

  • Measuring tape
  • Pencil
  • Hammer
  • Framing square
  • Circular saw or miter saw
  • Clamps
  • Level

Explore Shingle Styles

As professional roofers, PJ Fitzpatrick offers homeowners many styles of shingles. We install architectural and luxury shingles as well as shingles that repel the heat of the sun. Take a look at our roof shingle gallery and ask us for a roofing quote today.

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