I'm finishing my basement, and due to height, I'm doing a double top plate. due to length I will have staggered seams overlapping by 4' or more. I'm planning to stick frame, so attach the double top plate and the bottom plate, then fasten studs in the middle after. What is best and code for the double top plate. is it best to fasten both pieces together to form the full length plate, then drive screws through both pieces to the upper joists/blocking? or should they be attached one at a time (nail/screw the first top plate piece to the blocking, then attach the 2nd piece of wood to that piece)?

 

A double top plate is not needed for a non-load bearing wall. If you need extra height you can buy longer studs and cut them down or double up the top or bottom plate or both as needed. How exactly to do it all depends a lot on if you are working alone or have help.

If working alone you may want to put each piece of top plate separately to minimize the weight your holding up with one hand. If you have help for lifting and holding you can double the plate before putting it up. Remember, you don't need a double plate so the doubling can be located on the floor where it's easier to work with.

If you have the room it's usually easier to frame a wall lying flat on the floor, then stand it up. This requires measuring at several points along the way since thing, especially concrete floors, are rarely perfect. You may find that the studs need to be cut to different lengths.

If you want to do the framing vertically I like to lay the top and bottom plates next to each other on the floor and mark my stud locations across both at the same time so they are identical. Then I mount the top plate first. Next use a plumb bob to transfer the location down to the floor for the bottom plate (pressure treated). Then add your studs last.

 

Having a double top plate will provide you with more wood to attach drywall to at the top.

 

I just build them 1/1/2" under the height from floor to bottom of joist (single top plate) tilt them up and use pieces of 2x4 and/or shims between the top of the wall and bottom of the joists to run screws through to attach,

 

I found the 104" studs, and they are the same price as the 10' studs. I may just do 10' studs and use the extra for blocking etc.

In one wall just to get it done I did 3 top plates due to the height. Hope my Electrician and Hvac installer aren't too upset with it! if its just one wall, maybe they can avoid that if needed.