Small Pieces of backerboard
 

I am installing a new granite countertop over the holiday and have a question about how to install these small pieces of hardie board. IT is 1/2" thick and about 1.25" inches tall.

I tried using hardie board screws and it broke in half. I also tried using some roofing nails I had with the same result

should I try drilling pilot holes through the backerboard so it goes through no problems???

here is what i am trying to do

my other idea is to just apply the mortar directly to what is already there although i would prefer to not go that route as IT is not correct

did you try predrilling the holes for the roofing nails?

Are you simply using that as a sub base for a slab?

If so the cracked backer should bot affect the slab---you did not mention the brand of backer board---Hardie is difficult to set and frequently had issues with protruding screw heads----I use Wonder board or Durrock.

Those pieces will have 1.5 inch pieces of granite attached to them

Finish attaching the backer--set the slab in a bed of thinset and you will be fine---

Next project use Wonder board--