I have a laundry room attached to the back of the house (was done by previous owner). Recently I found a leak (due to some nail wrongly on the shingle exposed). But then when I "uncover" below the roof which is the ceiling, I saw this structure:

enter image description here

Just to help understand better, here is the framing NOW:

The "blue" is roof rafters of the existing home structure. I suspected the previous owner built out a patio roof section and then add the laundry room which is the "red" color rafters above. However, the laundry roof was "hang" on the "green" lumber w/ U-bracket and use it as a "ledger".

What are my options? I am thinking:

Option 1: Do nothing. It's just 4.5 feet so that 2x4 ledger might be good enough?

Option 2: Redo the entire roof of the laundry room by doing the below. Basically re-run the rafters higher so it's on top of the existing beam ( 2x 2x4 on top of the gray studs):

enter image description here

Please advise.

1 Answer 1


Your Option 2 is still not going to be a really great solution. If you are going to lay the new rafters on top of the existing rafters and existing roof sheathing you will need to taper the upper rafters as shown below. This way there can be a smooth transition of the roofing materials from the existing roof down onto the new extension rafters.

enter image description here

Ideally the solution would have the full width of the new rafters up above the double top plate of the original wall but full width out somewhere along the old rafter tails is going to be workable as well. Overall this will be way better than the hack job done for the original build.

  • Yes this is what I was thinking actually. Basically it's a bird mouth join. But I am wondering if Option 1 is even OK?! So far look like it has been holding for few years. There is no sign of collapsing :P
    – HP.
    Dec 9, 2019 at 6:45
  • @HP. - I would be inclined to suggest that you not do a birds mouth join. That type of join is used on the bottom end of a rafter on top of a upper double plate. Even thinking of doing such implies really digging into and tearing out out the existing roof sheathing...way more work than necessary. I would lay the new tapered rafters on top of the existing roof sheathing positioned directly over the top of the existing rafter...but hold off doing that work until you are ready to re-roof the main roof. It would be tedious to patch in a decent roof splice to the older upper existing roof covering.
    – Michael Karas
    Dec 9, 2019 at 7:17
  • The main roof is very new so I assume the previous owner got it done within couple years back. So I am wondering if this Option 1 is what you are referring to in term of holding off. But to clarify in recommendation above, should I even remove the existing red rafters? Because look like the new ones are higher so the old ones can be left alone and not be used per se.
    – HP.
    Dec 9, 2019 at 7:27

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