I want to attach a ledger board, over the existing wood siding. Something similar to this, but immediately underneath the roof


How do I determine where I need to drill the holes to attach it to the siding - basically, how do I find the joists?

An additional complication is that there is just a small distance between the roof and window edge


Are there any drilling recommendations, to avoid hitting wires or whatnot?

  • is this going on a house or a garage? Do you have access to the inside where you can find a stud? Commented May 14, 2014 at 21:04
  • it's attached to the house, but I don't have access to the full length from the inside.
    – funtastic
    Commented May 14, 2014 at 22:47
  • If it's immediately underneath the roof, you may be able to attach to the top plate of the wall instead of the studs. Do you have any latitude on the height? For example using joist hangers to attach instead of the rafter hangers in the picture above would have moved the ledger up 5.5 inches.
    – Comintern
    Commented May 14, 2014 at 23:16
  • Since this is such a tight space, are you planning on using trusses since you have had a picture showing a truss detail? Is your siding cement board or vinyl, I can't tell from the picture... This answered will help form a better answer. You mentioned you have wood siding but the texture is of embossed cement board or vinyl
    – Jack
    Commented May 18, 2014 at 4:05
  • If it is wood siding and you do not wish to remove it, you should be able to locate the nails holding the siding on. They will be up from the bottom edge about an inch up, small nail head. Over the window there will be a solid header, fastening anywhere will be found there. You really should remove the siding, it will improve the shear of the nails or screws, whatever fastener you my choose.
    – Jack
    Commented May 18, 2014 at 4:11

2 Answers 2


Since the new rafter section will cover any siding you may remove, layout how far the rafter section covers the siding and cut it about a 1/4 to a 1/2" lower. This will let you find the framing pretty easily, even remove a little subsiding to confirm, careful how deep you set your saw. This will show any conditions you may need to attend to. Set the bottom of the ledger at the on a chalk line set at the level you predetermined before you cut the siding. Set a ledger at the top of the rafter section as well to control rotation of the new section. This is an expansion on what Comintern suggested with his ledger and joist hanger idea, make sure the joist hangers approved for your framing condition.

Here is a little sketch to help illustrate. Doing it this way will allow a finished ceiling to go uninterrupted to the existing wall.

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  • Jack, thanks for your diagram! The trouble I have is that the distance between the roof and window doesn't allow me to add a double ledger. I've added an actual picture of how it looks.
    – funtastic
    Commented May 16, 2014 at 2:45
  • If you are looking for a flat ceiling like you shown in the first pic, you could make a "well" around the window, if you need to use trusses, again like in the pic. If your span is small enough, you may only need roof rafters, and no ceiling joists at all, and stay above the window. Or you could pull your gutter and blocking between the existing rafters and use your existing exterior wall top plate, like Comintern mentioned to support a wide enough rafter to carry the span. This will allow your new roof to "plane in" with the existing.
    – Jack
    Commented May 16, 2014 at 3:14
  • So you're suggesting I could do something like this, right?The red rafter would attach to a ledger board connected to the top wall plate. Would connecting the red rafter directly to the roof rafters work, without the need for a ledger? The other solution I was considering would be to support the ledger using vertical poles next to the wall, but I don't really like the idea.
    – funtastic
    Commented May 18, 2014 at 5:50
  • No need to add poles, and to expand on your idea in your sketch that you have, and you will be removing roof to do so, remove a little more to set your new rafters on top of the plate, or, cut off the existing rafter tails, since the first thing I mentioned potentially opens up your house to the weather, add the ledger to the wall, there you have complete access to fasten to the top plate. If your sketch is accurate in the small details, the ledger will still miss the double top plate. I will redo my drawing above to reflect the idea, using your sketch as a guide.
    – Jack
    Commented May 18, 2014 at 13:16
  • I overlooked answering all your questions. first one, yes, but with the changes I mentioned above. Second, no the overhang of these rafter tails are not considered structural to support a roof extension, they can be nailed into to help hold the new in place, but not for load support.
    – Jack
    Commented May 18, 2014 at 13:21

Rafter Splicing

First remove your current fascia board.

Splice to the ends of your current rafters by sandwiching boards (cut to pitch) on both sides of each rafter.

This will allow you to continue on your roof's current pitch.

However, by doing so, this will eliminate any view or scenic visuals that your current windows provide.

Hopefully this will help you... or at least give you an idea.

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