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Community and Q&A

Bug screen for open joint rainscreen siding

RWalterS | Posted in GBA Pro Help on

I’ve seen instructions on using bug screen at the top and bottom of the furring for a rainscreen, but I can’t find advice on insect barriers when it comes to open joint siding.  Does anyone have advice on best practice for mitigating insect intrusion with an open joint siding detail?

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  1. Expert Member
    BILL WICHERS | | #1

    Coravent works well for this, it’s a little like plastic cardboard and has some structure to it. Many people have used plastic foam-like “ridge vent” material that is intended to be mashed under shingles too. That plastic foam is crummy as a ridge vent, but it makes pretty good rainscreen vent gap bug proofing material — just don’t smash it flat.


  2. RWalterS | | #2

    Thanks, Bill. Seems like ti would be very expensive to use coravent behind all the open joints, is that what you're advising?

    1. Expert Member
      MALCOLM TAYLOR | | #8


      Open joint siding is just that. It doesn't provide any protection against insect infestations or much protection against the elements, and I'm not sure you realistically can add those attributes without compromising the look - which is the only reason to choose open joint siding in the first place.

      Open Joint siding isn't really a rain-screen in the sense that most building scientists (or our building code) would describe one, and the walls need to be detailed in a different way, so that the layer behind provides all the water shedding details of a WRB layer, but also gives the primary layer of protection we usually rely on cladding to provide. If I was using it, my preference would be to go the other way and make it as open as possible to discourage insect nests and make it easier to periodically clean the cavity.

  3. Expert Member
    AKOS TOTH | | #3


    You only need a small width of material there not the full width of a ridge vent.

    The rolled ridge vent material that looks like a scotch pad is easier to work with for this. Just cut it into 2" wide strips.

    1. RWalterS | | #4

      Thank you, Akos. I feel like it would be easier and cheaper to staple a full 5' wide roll of aluminum or other durable window screen over the entire furred facade before installing the open joint siding?

      1. Expert Member
        AKOS TOTH | | #5


        The best is a perforated U mold that is the same width as your rigid insulation+rain screen.

        I've done the stapled window screen, it works but takes a bit to get right. Easiest is to staple it to the bottom of your WRB at a height where the strapping would overlap it about 3" then install the strapping.

        The windows screen doens't plug the holes as well as the ridge vent material and more work to install. Also pretty easy to damage during construction.

        1. RWalterS | | #6

          Thanks again. My question was not worded well, so I've edited it. I'm actually referring not to the top or bottom of the wall, but to the open joints between siding boards in an open jointed siding installation. Thanks for your patience.

  4. Expert Member
    BILL WICHERS | | #7

    I had originally thought you were asking about screening the top and bottom vents on a normal rain screen setup. For open joint siding, neither coravent or the foam ridge vent material will work well.

    I can think of two good options for you:
    1- more expensive, most durable: get small-mesh (less than 1/8” grid openings) stainless steel hardware cloth, put it up with overlap between edges of the sheets, then fasten the siding over the hardware cloth. 316 stainless will give the best corrosion protection, but will cost the most. 304 will be ok too, and a little cheaper.
    2- much less expensive, less durable: put fiberglass window screen up, overlapping edges between sheets, then fasten the siding over the window screening.

    Don’t use aluminum or galvanized screening since either will rot after a few years of exposure to the outdoors in this application. You may have some issues with debris accumulating between the screening and the back of the siding boards too, especially if you don’t get the screening stretched tightly before installing the siding.


  5. Expert Member
    Peter Yost | | #9

    Hi Walter -

    my architect buddy Steve Baczek ( does a lot of open joint wall cladding systems and he swears no insect problems without any bug screen system.

    At the International Builders Show in Vegas just some weeks ago, Benjamin Obdyke had a slick new open joint rainscreen system.

    I THINK the new system is in addition to this one:, but I am checking on that.


  6. Expert Member
    Peter Yost | | #10

    Here is the new Benjamin Obdyke open-joint rainscreen system, available starting in April this year:


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