installing 7/16" OSB on ceiling, ok to cut into 4'x4' squares?

[Duncan Horner]

I've used a jigsaw and drywall keyhole saw before, drywall keyhole saws might say "drywall" but I lost a bet to a guy once who said he could cut a 2x4 in 7 seconds.

For a long time I used the Fat Max saw, still have it, it'll go thru almost anything.

Trace the outline of the boxes, and cut to your heart's content.

[Bill Embrey]

I used my roto-zip and a spiral bit... cuts through the OSB like a warm knife through butter...

Bill (in OK)

[David G Baker]

Cutting holes in OSB with a RotoZip is easy if you have the right blade and move it in the right direction. I use a skill saw. It takes a little practice but it is quick and as good as almost any other method. It takes accurate measuring to do the outlines.

[Dave Zeigler]

I hung my OSB on the ceiling using a shop-made panel lift. I have a vaulted ceiling so using a pair of "deadman" T-braces really wasn't an option. It took me a couple of weeks, part time, to complete since I was working alone

My roof is constructed using engineered scissor trusses. My trusses need to have support 2x4's installed perpendicular to the trusses to keep them from racking and to keep the gable end walls from bowing. Appropriate ceiling panels such as drywall or OSB can be used in place of 2x4's on the bottom chord of the trusses. I ended up using temporary 2x4's during construction and removed them when I installed the OSB 18 months later.

If you have trusses, you certainly want to stagger the joints and you may want to leave the panels 8' long. Contacting the truss manufacturer in that case is advised.

Thanks for the tip on the rotozip for the outlet boxes. I have a dremel with a "router" base, but I can chuck an 1/8" spiral cutting bit in it. That should save me some time when I get to covering the walls.

Dave

[Mike Gager]

i have a spiral saw with a 1/8" bit but maybe i dont have the right bit for osb because all it does is smoke and burn and turn the bit black, it doesnt even cut. it takes the same bits as the rotozip is there a specific bit i should get?

[David G Baker]

Mike,
The direction you move the spiral saw is critical to making the cuts. I think the direction is counter clockwise but it has been a while since I have used one. The Borgs should be able to answer your question if no one here can. Another possibility is to google RotoZip they may have the answers and may even have a video demo.