Butt-board substitute for ceiling butt joints
Greg_L_VT
| Posted in Construction Techniques on
I’m intrigued by the butt-board method of making butt joints in drywall MUCH easier and faster to finish with better results than the old way. I think I may have hit upon an alternate method that is easier and doesn’t require a butt-board per se. I am strapping my ceilings using 2 1/2″ AdvanTech (3/4″ thick) rips. Every 8′ where I would normally put a regular strap I will instead be putting in a 5″ wide strip of 1/2″ or 5/8″ plywood or sheathing. When I screw the butts (sorry) to the thinner strip of strapping (say it fast) it should create that shallow impression that’s easy to tape and doesn’t require 36+” inches of feathered mud. Has anyone ever done it this way? See any problems with my idea?
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How far apart are your joists? I suspect the 5/8" (or 1/2") strapping will flex down between the joists such that you would get your drywall depressions where strapping is attached to the the joists, but not in between the joists.
The TJI's are 16" OC. That's a good observation about the potential for flexing. Before giving up this option, I will add some additional short rips of subflooring to bolster the backside of the thinner straps. As I ended up using 1/2" plywood for the butt joint strips, I will also add a bit of additional material to the face of the strapping to reduce the amount I am trying to flex the 5/8" drywall. I"ll report on the results of today's test installation.
Follow-up: Per my previous note, between the TJI's I added 6" wide rips of the AdvanTech to the backside of the 1/2" plywood strapping. Lacking something like 1/8" Masonite, I stapled a double strip of Vycor flashing (with the backing left on) to give me a little more thickness on the face of the strapping. A 1/8"-3/16" gap remained once the drywall was put up. It bent very nicely with no screw-head pops or disappearing into the dw. Holding a straight edge up to the joint shows a nicely tapered space about 16" wide and 1/8" deep. I think it's going to work well with a perfectly flat joint when all is said and done. It sounds like a lot of "fussin' and foolin'", but once the parts and procedures are set up, it doesn't take that long and beats the heck out of a traditional butt joint.
Butt boards have a slight slope so that the drywall is fully supported on back side.
For the additional cost they are superior to your suggestion.
That's true. I have considered making my own butt boards (it's pretty simple and I've got enough leftover OSB/subflooring around) and likely still will if I'm not satisfied with the results of my experiment.