scubadude Wrote:Gary,
I don't want to muddy up the waters any more than they already may be, but I would like to offer a suggestion on your rocking plans. Don't want to contradict the Good Doctor, but in my previous life, I was a tape and bedder for a contractor and taped many houses. In those days, we did it all by hand, no mud boxes, bazookas or anything like that. A pan of mud, pan rack w/tape on my hip, a 6" tape knife, 10" and 12" bedding knife was all we used. Made for nice, staight walls. If it were me, I would consider hanging the rock horizontally, not vertically. Sheetrock has depressed edges along the long side, designed to give a little indention to fill with tape and mud. If you hang them vertically, you are going to have long 8' seams to hide, not as easy as it sounds. You will also have a wavy wall, as it is very difficult to nail up the middle of the rock where there are no seams and effectively spot the nails with mud. BTW, you should spot those nails 3 times to cover them so they won't show later. I would suggest hanging the rock similar to brick, cut a piece in half and stagger the joints where you have both horizontal and vertical joints. Start with the top and work down. Your first piece should hang horizontally along the ceiling, then stagger from there. It will be a little more work, but the end result will be straighter and less "friendly" (wavy). You will be glad you did, especially if you are doing an around the walls shelf layout. Also, if you have any corners, don't tape them , use metal corners and nail them in and bed the corners out 12'' on each side. Much stronger and will withstand bumping and knocks better than tape when you start benchwork, etc. You should also buy a sanding pole and lightly sand down all the mud joints and nail spots. Every teenie weenie mistake will show after you paint. I also suggest you texture the end result with a crowsfoot pattern. You can buy the necessary texture brush at Home Depot, as well as the hand tools I mentioned above. It will add another seamless thin layer of mud to the walls and strengthen them more and help hide "holidays", (mistakes).
No one should worry about contradicting me, scubadude - my wife has done it for years.
:dumb1
In fact, if your reply had been written by her, I would've immediately admitted the error of my ways, then banished myself to the basement.
For an experienced drywaller, applying the boards horizontally saves time (taping), but I have to honestly say that I have never seen an invisible butt joint. In a normal room, this is less of a concern, as most people don't drop by to inspect the quality of your walls.
Some lighting, however,
can really highlight this type of joint.
On a layout, where lighting is (or should be) much more intense, flaws in the wall are readily noticeable, especially in photos. Also, depending on layout height, one can choose whether or not to tape the entire joint - I elected to not do so, as anything below the layout, while still accessible, is not normally seen. Of course, when the layout comes out, all those areas will need to be done, along with re-boarding and taping all of the coved corners. (Maybe wifey will do it.
)
The average guy doing drywalling isn't all that skilled with a drywall knife, so feathering out those butt joints to be invisible under layout lighting could be a tall order. As for the walls being wavy, the main cause of that should be attributable to warped or bowed studs. Many people, including a lot of "professionals" apply way too much mud and then also leave way too much of it on the wall. I'm sure that Gary will continue using screws, mounting the boards with them, too (and, in my opinion, the only way to go) and the screw heads, properly set, need, literally, only to be covered. I agree, three coats are usually necessary on account of shrinkage, but only the screw head needs to be covered, not any of the surrounding area, unless it's been otherwise damage. In new houses, I more often than not see large splotches of already sanded mud covering screw heads, supposedly all ready for painting.
The same situation exists where too much mud is applied to tapered joints, extending out up to 10" or 12" on either side of the joint, be it horizontal or vertical. The taper on board edges is very distinct, especially when viewed under oblique lighting, and clearly does not require (nor accommodate) mudding beyond its edges. To do so
will introduce waviness into the wall, just as will the feathered mud covering horizontal butt joints.
To aid in screw placement, it's easy to first, before boarding, mark all stud centres on the floor and ceiling, then, if you have a crooked "eye", like I do, drop a line (a nail on a string works fine - secure the top with tape or loop it over a partially driven nail - remembering to fill the nail holes, of course, when you're done
).
I agree that any outside corners should use metal corner bead, although I think that Gary is planning to cove most or all corners. As for inside corners, regular paper tape stands up well-enough, although is not required if the corners are to be coved.
As for textured finishes, they're often used in homes on the ceilings, where they help to hide waviness and other irregularities. You'll still need to tape and mud the joints, though (the worst part of drywalling, especially the sanding, in my opinion), and I'm not sure that here it would be of further benefit. After all, there will be no windows which would otherwise allow outdoor light to show-up any irregularities, and with the light fixtures mounted on the ceiling, with most of the light directed downward, I doubt that the ceiling would be noticeable at all. As for textures on the walls, you definitely don't want them, as they'll show in photos, and you won't need them anyway, as there should be no noticeable flaws that would need covering-up.
To get a really good finish when doing your final sanding and touch-up, use a hand-held "trouble light" to obliquely light the area as you work. Held close to or against the wall surface, even a spec of fly poop will stand out like a boulder.
This technique is, of course, not practical for most large-scale applications, but for a layout that will be under intense scrutiny via the camera's lense, the extra care is well worth the effort.
The choice for all of this is, of course, up to Gary, so it's good that he have as many options as are available from which to choose.
EDIT: When attempting to post this, I got a caution that other replies had been made while I typed the foregoing, so I'll comment on them now.
There's absolutely no reason that vertically applied boards will bulge in their middle unless they're applied improperly. After the sheet has been set in place, it should be butted to the adjacent piece, then levered from the bottom to butt the top edge against the ceiling. The bottom edge should
not sit directly on the floor,
especially concrete.
To fasten it in place, start at the butted edge, preferably near the top, and do the entire edge, then the entire row along the next stud, and so-on, until you reach the opposite edge. The same rules should be followed if you board horizontally. Doing the edges first, as many professionals do (I saw a well-known TV handyman doing the same thing with flooring plywood just last week) introduces and traps bulges in the centre of the sheet, and these will continue to cause problems long after they have been installed, including "popped" nails
or screws and cracks along the seams.
Sorry, but extending the mud beyond the taper creates not only more work and waste, but also poorer, more visible joints. The taper in the board is designed to save work and yield an easily-created
invisible joint.
Wayne