When hanging blue board for veneer plaster, should the board overlap on outside corners like normal drywall or should they end on the edge of the studs and the corner will be filled in with veneer (and a corner edge piece)?

2 Answers 2


Corner bead is used on plaster work too, so run it the same way as you would drywall. My preference is to run one piece over the edge of the other side, but slightly behind. This can be achieved as well when the board is ran past the corner, then scored at the corner an broke back and finished cutting. Use a drywall rasp (cheese grater) to insure the break is back a little behind the corner if needed.

  • So I read this article - thisoldhouse.com/how-to/how-to-hang-drywall Where it says -- For outside corners, install the first panel so its end is flush with the studs on the adjoining wall. Overlap this exposed end with the panel on the adjoining wall, so that the corner is completely encased in drywall. (With blueboard, the panel ends do not overlap at outside corners; their ends land flush with the corner of the stud. This void will be filled later with plaster) Is that comment incorrect, or just a different opinion?
    – Derek
    Jun 18, 2019 at 22:03
  • After looking at the article and picking up on there will be a corner bead used, since I missed that on your question the first time I read your post, I can understand the premise for holding back the blueboard. I have never witnessed this being done one the jobs I ran that had this type of work being done, but I can't say it wasn't done that way. What they are doing is right since a corner bead is used, and the use of the corner bead is what I missed at first. Some reason I did not read where you wrote (and a corner edge piece)? I took it you were going to use plaster on the corner only.
    – Jack
    Jun 19, 2019 at 4:41

It doesn't matter. Some folks like to think that having wallboard behind then corner bead offers support. It doesn't. For one thing, it never completely fills the inside of the bead. No one is that precise. For another, it's wallboard, which is inherently soft. If the bead gets hit hard enough to deform it, gypsum or other wallboard material isn't going to help. The damage is done.

Most hangers cut flush to the framing. This eliminates the need for any rasp work, which wastes time.

I usually lap about half the width of the wallboard (along the lines of what Jack describes). It just makes me feel like I've done a more precise job of fitment. It doesn't matter, though.

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