I am getting ready to build a 16x24 cottage on piers, but the piers need to be attached to granite ledge which is about 3-6" under the surface of the ground. I think the way to secure the concrete is to drill a hole in the ledge, put in rebar and build a form around it and pour in the concrete. Is this the correct approach? What do you use to cement the rebar into the ledge? Thanks
Sounds right to me :) Drill the hole say 1/4 over sized and get some epoxy at the store . They sell a ready to mix kit . Follow the inst . on the tube . Ya use a drill motor to mix it,, have all your whole's drilled and rebar cut before you mix it .
Put the rebar in then build your forms . Good luck :) HTBH ;)PEG
There are some epoxies that mix as they come out of the tube- Hilti - expensive or Simpson Strong Tie- the strong tie is cheaper but takes longer to set -no problem in this application - holes 1/8 oversize brush and blow them out - have them dry for good grip- common embedments generally run from 4 1/2 inches to 12 inches depending on the application and engineer.
There are also pourable anchoring cements such as Rockite or Pourstone.
You may want to check with a local professional if you have any questions.
They sell a ready to mix kit . Follow the inst . on the tube .
This is key , follow the inst. on the tube ! HTBH ;)PEG