Originally Posted by glennjanie
The mortar will hold the wall up in that short a time but it is too quick for the concrete screws. I think they would strip out with the least pressure.
The theory on holding the bricks is that each brick supports only its weight above.
Sorry Glenn, what I meant is that I'd drill into the bricks, not the mortar itself. It would be to attach Hardibacker. The job site is actually an existing brick wall where I pulled off some top row bricks as they were jutting out. Some broke off flush with the rest of the wall; others came out loose but I wedged them back in. This is basically to solidify the wall a little before I slap Hardi over it. The rest of the 3-foot high wall is very solid.