In making a flat surface for a portable grill area, my plan was to attach Hardiboard backerboard to a sheet of 3/4" melamine/chipboard. That way, I could tile one side and when we were not grilling, I could turn the top over over and use the smooth white surface of the melamine as a table top.
I cut a sheet of melamine to size, an exact fit over the Hardiboard. I purchased the box of backerboard screws, as recommended by the clerk at Home Hell. Now I find it nearly impossible to screw the sheets together. The backerboard screw really doesn't grab the material, the screws are a little long anyway but were supposed to be self-drilling. Even if I hammer it in a bit and then try to lean on the drill, the screw makes dust, not holes. After a year or two, it finally penetrates the Hardiboard and then more or less pushes the melamine away. Clamping the sheets together didn't help much.
Should I use roofing nails instead? I don't want to ruin the melamine surface, these screws seem a bit long anyway. It'd be a drag to snip screw tips and have to refinish the surface. Is this just not going to work? Should I try some sort of bigtime construction adhesive instead of nails or screws?