GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Rainscreen Detail

will4 | Posted in General Questions on

I have a project where there will be a reverse board and batten siding detail. We bypassed blocking between studs on the interior, for nailers, so that it will be easier for the dense pack cellulose to be blown in. I am planning on putting 1.5″ x 2.75″ horizontal nailers 24″ OC on the exterior over the Zip sheathing to serve as a nailing base to the vertical siding. I know this has been brought up before, but just want to double check. Would it be beneficial to kerf the horizontal nailers where they meet the sheathing for water drainage? Or will the airspace alone with the sun hitting be adequate for drying.
I am located in the humid southeast NC. Zone 4b. Thanks.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Expert Member
    Michael Maines | | #1

    Will, the vertical battens should provide good air flow, so as long as your cladding is reasonably well sealed, any moisture that gets into your rainscreen should dry reasonably quickly. If you think a lot of liquid water will be getting as far as the WRB, you could add a drainable housewrap such as Obdyke's Hydrogap, or kerf the horizontal furring as you suggest. But as long as you have good air flow at the top and bottom of the rainscreen you really shouldn't have a problem.

  2. kjginma | | #2

    Will, what I am doing is taking the yellow Obdyke rainscreen material and cutting it into strips (to save a lot of money), stapling to the *back* of my 1x3 horizontal strapping -- the equivalent of kerfing without lowering the strength of the board. This allows the bulk moisture barrier (Typar) to drain quickly due to gravity. Be sure to leave an exit for bulk water at the bottom row of your cladding (in my case, more of the cut rainscreen stapled to the edge of the sill, underneath the cladding.

  3. Tyler_LeClear_Vachta | | #3

    Having a ventilated drainage gap is sufficient to dry the system out quickly. Another option instead of cutting the strips is a strip product from MTI called Corrugated Lath Strip designed for this type of application. They also manufacture full wall drainage mats. Full detail and links to product info at

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |