Expert: Dan Griffin - 5/27/2010

Question
QUESTION: Is there any difference using joint compound or wood filler between two pieces of plywood forming a wall?

ANSWER: Shelley, I've not ever used it with joint compound to tape joints between plywood sheets.  We shot some paneling one time with texture.  We did not do any kind of surface prep other than nailing anything that was loose.  I swore it wasn't going to hold and that we should at least wash and/or sand the surface, but my buddy said it would hold. We shot the texture and then painted with latex.  That was almost 20 years ago and I still marvel at success.  The room has been repainted several times and the texture remains in good repair.

I acan't swear it will work, but all indications seem to indicate it will.  Hope this helped.

---------- FOLLOW-UP ----------

QUESTION: Hi,

I need to clarify...so you can help me.

I am not putting texture on.  I am trying to treat the plywood as if it was sheetrock..building a wood wall.  There are seams between the pieces of a/c plywood.  What do I use to make the wall look like one piece without seams?  Thanks.
Shelley

ANSWER: Shelley , I already gave you the best answer that I can.  What you are doing is NOT normal.  It would be  normal to install a strip of screen mold or other trim over the top of the joint in the plywood.  Another normal treatment would be to bevel the edges of the ply and leave a very distinct and deliberate v goove between sheets.  You can also install a T-mold or H-mold in the joints - it will show, but may be better for your application.

I have NOT ever tried to tape and bed plywood - see my first anxwer.  If you smear commpound on the plyweed it will stick - see my first answer.  If you do not tape the joints, they will transfer through the compound and show as hairline cracks.

If you want more information, ask again, I may be able to come up with some other ideas.

---------- FOLLOW-UP ----------

QUESTION: Hi,

I wasn't necessarily going to tape..but what is texture?  I wanted to know what kind of compound would work in filling the space between the a/c plywood board on the wall so it looks smooth, like sheetrock?  What exactly is texture and did you use tape?  Plywood will breath(move) during moisture changes, weather changes.  The building isn't heated in the winter.  Is this to be considered?

Thanks,
Shelley

Answer
Shelley, drywall comes in sheets much like plywood.  It is made of gypsum covered with paper and is pretty stable through heat and cold.  It does have tapered edges to help hide the joints as a user tapes and beds the joints between sheets.  This is paper or fiberglass tape bedded in drywall compound.  I takes several coats with sanding between coats to arrive at a smooth surface.  The flatness and smoothness is subject to the skill level of the installer.  Most drywall is then given a coat of texture - this is the pattern of little bumps, lumps, or swirls all over the wall that help disguise small imperfiections in the smootness and to add dimension to the wall surface.  This is done by splattering, dashing, shooting, rolling, spongeing, or somehow getting a random but even texture applied to the surface.  The texture is the same drywall compound, sometimes thinned a bit more with water to achieve the desired effect.

Your plywood does not have the tapered edges, so the tape and bed process will build a very small ridge at the each joint that can be tapered out and become unnoticeable by a good taper.  Plywood moves a bit more than drywall through the humidity ranges and I cannot swear to you that the tape will remain stuck over time.  You can omit the tape and apply compound on the joints to close small gaps and even up the plywood joints and provide an easy to sand surface, but without the tape, I know you will get very small hairline cracks at each joint which may be fine for your project.  It would also be possible to apply drywall sheets over your plywood walls and arrive at a conventional finish.