Can you pally k rend to sandstone

Hi Drena Personally unless this is Breathable (which i believe it is not and silicon Based) i would not recommend this. Sandstone is a very absorbent and porous which needs to breath, if you render over with a water prof render or Cement based Product it can cause more damage to the stone over time can even result in internal dampness. Depending on size of repair there are many types of colour matched lime mortars available . You can also use a product called REMMERS, a German made heritage approved mortar, these are also available colour matched for sanstone and give great results but more expensive. Hope this was of some help. Regards Lee