Can you silicone render over existing render?

I’ve always removed the pebble dash to expose the brickwork and render directly on top of bricks/blocks. I feel rendering over pebble dash Could be risky.

If the pebble dash is in good condition and clean. One of the best ways of re-rendering pebbledash without removing pebbledash render is by smoothing over it with a One Coat Dash Cover (OCDC). This is the ideal material to use, because it can be applied at a thickness of 20mm thick without compromising structural integrity. You wouldn’t want to put a non-breathable material on top of the pebbledash because water needs to be able to escape from the walls, otherwise you may find yourself in an unpleasant, waterlogged situation and then creating internal damp problems

Clean any flack paint then stables with sablesing sloson then you can paint wot ever you like

no you should be asking a pebble dasher/plasterer

Silicone render is a 1.5 mm thin coat rendering system and it must be applied to a flat surface if the pebble dash has been painted then it cannot be flattened out without first removing the paint. Generally silicone render is applied after rendering with a mesh reinforced polymer cement in ordered to guarantee the work.