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Community and Q&A

Flashing between siding and brick?

FlowA112 | Posted in General Questions on

A few years ago I had the siding outside of my house re-done. The exterior consists of an upper half with brand new vinyl siding, that sits above the lower half of the house, which is faced with old brickwork that we did not touch.

In between the siding and the brick, there is a gap in the house that allows water to get behind the brick, causing what looks like spalling in the bricks. I have attached photos below. Prior to insulating my rim joists with rigid foam, these gaps even let daylight into my basement.

Should the contractor have installed some sort of flashing in the transition between the siding and brick, to ensure that this transition stays water tight?

Bases upon the feedback, I may call the contractor back to follow up. Thanks everyone. 

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  1. Expert Member


    Either flashing, or have lapped the siding over the brick an inch or more.

  2. FlowA112 | | #2

    Thanks so much, very helpful and confirms my suspicions.

    The contractor says he will take a look, but if he ultimately does not prove helpful, will some silicone or polyurethane caulk, or low expansion spray foam fill the gap, or are those approaches too much of band-aids?

    1. Expert Member
      MALCOLM TAYLOR | | #3


      It depends on how that bottom piece of trim relates to the siding boards. If they butt up to the top of it, water can get in there and you wouldn't want to plug up the drainage path for that to escape. If it sits on top of them then yes caulking is probably the easiest solution.

  3. Expert Member
    Akos | | #4

    "Prior to insulating my rim joists with rigid foam, these gaps even let daylight into my basement."

    That sounds like missing WRB. You might have other problems there. Do you have any pictures of the work before the siding was installed?

    Just quickly looking at what you have, it should work although the J channel on the bottom of the siding is not the best idea, that should have been a drip edge to channel water out from behind the wrb behind the siding past the brick.

  4. Deleted | | #5


  5. FlowA112 | | #6

    I’m trying to attach additional photos during the work, but unfortunately the website is telling me that there is a “problem uploading my file” despite being the correct size and file type. Maybe a glitch in the website at the moment.

    It looks like they did a WRB over the pre-existing OSB, followed by fanfold insulation to make an even surface for the vinyl siding. The WRB and fanfold insulation all end where the vinyl siding ends, which is just above the bottom of my rim joists. The brick on the front is the siding for my basement.

    Malcolm - would you mind describing a bit more what you mean by the trim “butting up to the top of” the siding boards versus “sitting on top of them?” If I need to caulk that gap I will, but I definitely don’t want to do anything counter productive like trapping water!

    Thanks again for everyone’s help.

    1. Expert Member
      MALCOLM TAYLOR | | #7


      I didn't realize from the photos is was vinyl siding, and that was a J channel. To be honest I'm at a bit of a loss for how to go forward without tearing out off the siding to flash the joint properly.

  6. FlowA112 | | #8

    Thanks Malcolm for the honest feedback. I will bring this up with the contractor.

    Akos, you are right, J channel is a terrible piece of trim for that joint. It collects standing water - I literally had to drill weep holes in it to get it to drain! And this siding job was not cheap either.

    1. Expert Member
      MALCOLM TAYLOR | | #9


      "And this siding job was not cheap either." It looks good. Hopefully the remedy is as simple as doing a bit of sealing and replacing the J trim with an extended drip edge tucked under the WRB.

  7. FlowA112 | | #10

    Malcolm, that makes sense as a potential remedy to look at. Thanks so much everyone for all the help. The folks on this forum have been an invaluable source of knowledge.

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