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How can I attach a ledger to an outside brick wall for a deck?

9woodworks9 | Posted in GBA Pro Help on

How can I attach a ledger to an outside brick wall for a deck when foam is used on the outside of sheathing?

I have 3 inches of foam then a 1 nice air gap, and I need advice on how to attach the ledger.

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  1. 9woodworks9 | | #1

    This is a picture of the foam

  2. Richard Beyer | | #2

    I would assume the same practice is used as was used in old brick structures. Carriage bolt through the entire assembly with a square washer on both sides to prevent pull through. Check with your structural engineer for the proper sized bolts and strength requirements for the loads you plan to carry.

  3. GBA Editor
    Martin Holladay | | #3

    Whenever a house has exterior rigid foam, a deck ledger shouldn't be attached to the rim joist. Instead, it's much better (from a water-management perspective as well as a structural perspective) for the deck to be supported on independent footings.

    This issue has been discussed many times on GBA, including in the comments below this article: How to Install Rigid Foam Sheathing.

    If you insist on trying to attach a deck ledger to your building, talk to an engineer. You might want to consult the detail shown below (a detail developed by the Cold Climate Housing Research Center in Alaska), although this particular detail was not developed for buildings with brick veneer.


  4. 9woodworks9 | | #4

    Thanks for your advice from the picture above how would the wall breath being brick ? Plus how would one put brick above the ledger and not worry about cracks later?
    On my project I was thinking putting pressure treated wood on top of the foam that would fill the air gap. Some thing like a 1x6 10 inches long that I could put the lag bolts through. That way the wall could drain if any moisture did get in. I was worried about tightening the lag bolts and crushing the foam ?

  5. GBA Editor
    Martin Holladay | | #5

    I will repeat my advice: abandon the idea of attaching a deck ledger to your house.

    Instead, support the deck with posts that bear on independent footings.

  6. Expert Member

    Michael, I second martin's advice. But if you do decide to go ahead, this isn't something you can DIY the details for. You need an engineer.

  7. Richard Beyer | | #7


    It's ok to pour a building's footing on top of rigid foam and construct a residential/commercial building on top of that same footing, but it's not ok to through bolt a solid ledger to support one end of a deck?

    We both know the other end of the deck would rest on a column. Do you think your capable of torquing down a carriage bolt enough to compress rigid foam to failure? I would assume this proposed deck is not cantilevered. Either way, contact your structural engineer and building official. It can be done, it's all in the details.

  8. Expert Member

    Richard, I don't think the foam's compressive strength comes into it. There is an airspace between the foam and the brick. The carriage bolt won't take the vertical loads, the brick veneer effectively becomes load bearing. That's something very unlike traditional masonry construction and needs a pretty sympathetic engineer to approve.

  9. 9woodworks9 | | #9

    Thanks for the advice .......

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