#9 x 1-5/8 in. Serrated Flat Head Star Drive Cement Board Screws (140-Pack)

Yes works fine for 1/4 in cement board

No not needed

If you are just attaching the Cement Board to a wooden subfloor then a screw shooter will do fine. You will need to adjust the depth to just slightly countersink the screw heads. If you don't do that the screw can easily bore right through the board and will crack it if you are too close to an edge. I think that the recommendation is not getting closer than three inched from an edge. Now if you are attaching this to a concrete floor, you will need to pre-drill with a small masonry bit. That might take a little practice to determine the drill size and depth.

Unless local code says otherwise, if you spaced them properly you should be fine. The thread on these screws hold very well. I would not replace. If code requires, you could buy another box and add to the existing sheets.

No

Hi Ben. The Rock-On cement board screws will not be able to screw directly into brick. They are designed for attaching cement board to wood or light gauge metal studs (20-26Ga.). One solution is securing furring strips to the brick with a flat-head Tapcon anchor, then using Rock-On screws to attach the board to the furring strips. Please reference the cement board manufacturers instructions to ensure you maintain their warranty. They may have other solutions available as well.

You may have to remove the brick or fur the brick out then install the cement board .

I used about 20 screw per board

Yes

Rock-On #9 x 1-1/4 in. Serrated Head Star Drive Cement Board Screws have threads similar to drywall screws and should penetrate metal studs just fine. To make sure try screwing one into a metal stud to see how easily it self drills into the metal. Good luck with your project.