I've been here before......Its not very difficult to modify certain circular saws to a zero clearance on one side. Once done its a lot more difficult to return the saw to its original configuration. I made mine from a yard sale $5.00 saw. Wish I still had it, I would take some picks of it for you.

How about your angle grinder ... use a thin cut off blade, set your guard to the req'd depth and cut away.

cant you just score it and snap it off?

i have one of those vibratory saws that would get thru that..but you hands would be numb

Sawzall. If you just get close to the corners you can pry the sheet off, then finish off the remaining corner pieces with a hammer and chisel. If you don't have a Sawzall, it will be worth every penny. The name says it all......

Let me know when you start to do that. I will just drive to another county for the day just to avoid getting hit by your grinder when it pinches and fly off your hand. That's nuts. I know there are many tools out there, some are not so safe and that's one of them.

The trick with a plunge cut on the Sawzall (ahh, that's how its actually spelled? I have never noticed) is to make sure the foot is always in contact with something. Jam the foot onto the OSB and plunge the blade into the material or lift the saw from the back end. Once you get a little spot going, the rest goes pretty easy.

Cut-off tool. You can get them air powered or electrical. Put a wood blade on it and remove the shield (wear glasses when using).

http://forums.pelicanparts.com/uploa...1415689124.jpg

If not a good sharp chisel and hammer, what about this Dremel with depth guide?

I think that would work great:

http://mdm.boschwebservices.com/file...0r24931v17.jpg

As usual, The blade I want has been patented, but not produced. It has a very long convex cutting edge,
I did find this and ordered it (cheap) so we'll see.

I like that lancelot thingee. Does it jump/kickback like a chainsaw?

http://forums.pelicanparts.com/uploa...1415711589.jpg

Yep...looks a lot safer than most of the suggestions and is designed to make a flush cut (when you put on that blade). There is a video clip of one posted near the top.

In the past i have made a blade like that. its not hard to cut teeth with angle grinder. might take a few times to sharpen it up to do all that but itll work. a vibrating miltitool with a good blade should work good too. we have a Fein Multimaster. harbor freight has a cool grinder wheel that has a chainsaw blade around it. id say that should work too. or just use a chainsaw

This, but I would probably cut the sheathing as close as I could with the circular saw first. That would leave a piece about 1.5" wide sticking down. Once you strap the joists and put drywall up there a piece of cove will cover the small edge of sheathing.

Best
Les

Holy carp that looks like something out of a horror movie!

http://forums.pelicanparts.com/uploa...1415721076.jpg

Cut???
The plywood appears to be nailed in place. If that is the case, you'll eventually end up with a nail pulling devise....like a claw hammer/crow bar. There are special tools that will pull the nails.....powered by your basic hammer.

https://www.festool.com/Products/Pages/Product-Detail.aspx?pid=767998


http://forums.pelicanparts.com/uploa...1415724089.jpg

The sad thing is (being a tool addict) that I will most likely end up buying ALL of these tools just to have them, even if the $4 sawzall blade is all I need.
Thanks guys.
Ron

They keep it safe by limiting it to 14000 RPM.

https://www.sunbeltrentals.com/equipment/detail/995/0040070/toe-kick-saw/

Toe Kick saw rental - in my zip - $15 for 4 hrs, $21 for a day. And be done with it!