I have a plywood ceiling on an outdoor patio that is under the roof of the house.
The paint is checking a bit in places, and the joints are not taped. Since its been there for 50 years, and I don’t want to rush into anything, What do I use to tape the joints on the plywood? Will paper or mesh tape and Durobond compound work? And will setting compound let me smooth where the paint scaled off or do I need to get more creative?? hmmm, maybe another 50 years…(nah, the war dept. wouldn’t let that go)
Bud
Replies
Most I have seen covered the joints with either screen mould or lattice. I usually use plybead which has the rabbeted joints that do not show. I wonder how floor leveling compound (sometimes called underlayment) would work. I would be concerned about regular drywall compound outside unless it was durabond or equivalent.
Bob
Even Durabond is not moisture proof. Yes, it is somewhat more moisture resistant than regular joint compound, but I doubt that it would hold up outside.
-Don
I know that it would not tolerate direct moisture but I believe it might have a chance with just moderate humidity.
It's pretty common to use moulding to cover the joints.
I'd use an astragal profile and make panels on the ceiling so it doesn't look like you just used moulding to cover the seams.
Or you could elaborately coffer the ceiling. Make it look like this: ;-)
View Image
"Let's get crack-a-lackin" --- Adam Carolla
Taping plywood joints is so uncommon that I can't remember ever seeing done successfully on a house.
Having said that, I'm 99.9% sure it is quite doable if we take a page from wooden boat building, where plywood edges are sealed with epoxy and fiberglass tape.
You'd want to sand down to the wood for 4" on the perimeter of each sheet (8" at the joint) to ensure anything put there has something to stick to. Then fill any gaps with a sawdust/epoxy mix to have a nice flat surface.
Finally, a 6" strip of fiberglass mesh wetted out with epoxy will hold it all together. The fiberglass mesh that I'm thinking of is the type used in automotive or hobby applications, not the much thinner mesh tape used with drywall. Bondo would be my choice for a filler to smooth out the joints.
It would be a substantial amount of work, which is why it's so uncommon.
Cheers,
Don
seb,If you use Trout's suggestion, it will work, but mixing Bondo and epoxy can be a problem. Epoxy over fully-cured Bondo is okay, but Bondo over fully cured epoxy will interact badly and likely fail right away.Bill
Bondo over fully cured epoxy will interact badly and likely fail right away.
What?
What do you think body shops use over fiberglass repairs to fill out the shape and smooth everything?
Hi Trout,Auto body shops use Bondo over their polyester and glass repairs. Both materials are the same chemistry. Auto body shops do not typically use epoxies anywhere for their repairs. Epoxy is not the same chemistry as polyester, and the fresh polyester is destructive to the cured epoxy, leading to bondline failure.More information can be had from Gougeon Brothers, who make the WEST System epoxy.Bill
Working with epoxy is a PITA. (I can say this with some authority, having epoxied together a kit boat.) Not worth it for a plywood ceiling, and not likely to give a smooth finish.If I had to tape it I'd use mesh drywall tape and cover it with either setting compound or (better) a premixed spackle.But some sort of lath over the joints makes much more sense.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
Drywall mud and tape will fail regardless of what is used. It is not designed to go on plywood. You would have to cover with layer of drywall and then tape. You would still have to deal with drywall out in the elements and the mold and mildue issue. Not recommended.
OK , got all that...Not what I was hoping for..This is the dry desert of the front range of Co. but I see the wisdom of all who posted..
The really great one was the pic of the great coffered ceiling...Don't want to show that to the war dept...Jeeze...
Think will just use some painters caulk in the small spaces between the sheets, some spackle on the nail depressions, Paint with some exterior paint, and forget it for another 50 years....If I decide to enclose the thing I will drywall it on top of the ply and be done..
Again, thanks for the replies..
Bud
I've several times seen plywood done with a textured paint. Hides joints pretty well if it doesn't crack or peel.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
Working with epoxy is a PITA.
Like everything, the more you work with it the easier it gets.
If anyone is interested in learning more, check out the Aircraft Spruce Supply website and order a catalog or download the PDF. The catalog has a very good how to section well worth the free price. They also sell all sorts of supplies.
http://www.aircraftspruce.com/
I have a feeling the tape over ply will look worse after you get done than before being that I doubt you'll ever make it look like one..It'll always look like a repair...............although who knows?
Thats why you always see lattice or astigal on those type seams it seems..
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If you don't like the look of ply, you could install t and g fir or pine.
It'll move with the ply over the seasons instead of fighting it like drywall.
Edited 5/15/2006 11:04 am ET by jackplane