How to add a covered patio roof to an existing roof line

Written by chuck brown
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How to add a covered patio roof to an existing roof line
Covering a patio will keep it cooler, allowing you to enjoy it more often. (patio image by ded from

While patios can add a lot of family enjoyment, summer heat can make them unbearable. Covering the patio solves this problem. It allows you to reclaim those summer months of patio enjoyment with relative comfort. Whether you cover it with a retractable awning or elect to make the covering a more substantial structural addition, you are sure to enjoy your newly covered patio.

Skill level:

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Things you need

  • Tape measure
  • Chalk box
  • Level
  • Screw sun
  • Ratchet wrench
  • Screws
  • Bolts and washers
  • 2-by-6s
  • Sliding bevel
  • End posts
  • Roof sheathing
  • Drip edge
  • Roof felt
  • Shingles

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  1. 1

    Locate the ledger first. The ledger is the 2-by-6 to be nailed into place first. It will run the width of the patio, and the patio roof is attached to it. Locate it just below the eaves (overhang) of the house, if the house is single story. Find the band joist and attach it there, if the house is two or more stories. (The band joist/rim joist is the 2-by-6 or bigger that separates the floors of a two or more story house.)

  2. 2

    Remove the siding, down to the sheathing, to expose enough area to screw or bolt in the 2-by-6 ledger to the side of the house. (Note: If the siding is fairly flat, attach straight through it without removing it. Always remove clapboard, bevelled wood, aluminium and vinyl siding.) Use an inverted piece of bevelled horizontal siding (creating a flat surface to attach to) if that is what you have on the house.

    How to add a covered patio roof to an existing roof line
    Covering that patio will get it out of direct sun light (Red patio furniture image by Scott Latham from
  3. 3

    Screw the ledger in place to hold it while you attach it more solidly with bolts, washers and nuts. Check for level as you insert the screws. Ideally, attach the ledger by pre-drilling holes and running bolts through the ledger, the sheathing and rim joist and attaching nuts and washers from inside. If inside wall access is blocked, plan to use ½-inch thick lag screws and attach to the wall studs for the entire length of the ledger. Drill the lag screws into wall studs on a single-story or the band joist on a two-story. Use expanding anchor bolts to attach to brick.

  4. 4

    Attach joist hangers to the ledger to secure the rafters. Install them at 16 inches or 24 inches on centre. Erect and plumb the two support posts at the other end of the patio. Join them with a ledger that will receive the other end of the patio roof beams. Nail in joist hangers/saddles to line up with the hangers already installed in the ledger attached to the house.

    How to add a covered patio roof to an existing roof line
    Attach rafters to hold sheathing (Porch Hammock image by Andrew Kazmierski from
  5. 5

    Mark the patio roof rafters with a sliding bevel to give the rafters the required drop angle. Cut and drop them into the joist hangers. Check the end posts for plumb one more time. Nail them into the rafter hangers and saddles. Nail in the rafters on each end first, then the others. Chalk and cut the rafters to the same length, after they are all installed. Nail up the 2-by-8 fascia board, attaching it at the rafter ends.

  6. 6

    Install sheathing to cover the rafters. Stagger the sheathing seams every four feet to avoid continuous seams. Cover the sheathing with roofing felt. Install the drip edge and shingles.

    How to add a covered patio roof to an existing roof line
    Nail down shingles to protect that patio roof (roofers working together image by Leticia Wilson from

Tips and warnings

  • This is an advanced carpenter's project. Hire licensed professionals if you have never done a job this complex before.
  • Never pay any contractor in advance for work. Always get references.

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