new guy here. I am hoping you guys can help. We had a 2x6 built Wisconsin Homes modular placed on top of an ICF basement. Then, we had vertical vinyl board and batten siding installed, it was run down so the J Channel sits a half inch below the sheeting. This left the sill plate exposed.

The concrete contractor ran mel-rol waterproofing up to the top of the ICF. This shouldn't be exposed above grade, so my plan is to peel down the waterproofing barrier and cut it off to remove it before applying sticky mesh and synthetic stucco where the foundation will sit above grade.

My question is, how the heck do I hide the sill plate tastefully?

I contacted styro industries, the makers of Tuff II and FlexCoat synthetic stucco and they don't recommend covering the sill with this product.

I thought about running 1x4x16' lp trim board all around and nailing them to the sill then stucco below that, but not sure if that is a good idea or if there's a more economical solution?

Also, should I coat the bottom of the sheeting boards with something, rather than leave them exposed? See pics for reference.



1 Answer 1


You could install a trim board, but that doesn't adequately address water drainage. You'll end up with water behind it, rotting out your sill.

I would do your stucco/parge coat, then install color-coordinating Z-flashing over the sill plates. The flashing should be inserted behind the siding channel (and any housewrap or other flashing), so you may need a custom bend to accommodate your dimensions. It should lap onto your stucco a reasonable distance (say an inch). Ideally it will terminate with a hem for stiffness and a finished appearance.

  • At this point I am not sure how I would be able to get the Z flashing up behind the siding or behind the sheathing, This is a pretty bad situation.
    – EskoBuild
    Commented May 28, 2019 at 14:29
  • I didn't say behind the sheathing (it protects the sheathing), and the siding channel is mounted at the top, leaving it loose at the bottom. Not really a problem. Give it a tug and you'll see what I mean.
    – isherwood
    Commented May 28, 2019 at 14:34
  • I think I get what you are saying now, would it be held in via pressure or how would I fasten it?
    – EskoBuild
    Commented May 28, 2019 at 14:57
  • Just a few color-matched exterior trim nails into the sill plate, probably. Say every 24".
    – isherwood
    Commented May 28, 2019 at 15:03

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