How to paint over pebblecrete?

Cobbly

I have a small area of floor I am wanting to paint, it is half cement and half pebblecrete. Wondering if Rust-oleum will work and if so which product do you recommend.  A builder was concerned paint would not adhere to the pebblecrete.  How would you recommend I prepared / clean it?

MitchellMc

Welcome to the Bunnings Workshop community @Cobbly. It's wonderful to have you join us, and many thanks for your question about pebblecrete.

I’d share the same concerns your builder raised. Pebblecrete is essentially a surface made up of small stones bound together with a resin, and that resin makes it very difficult for paint to properly adhere. Even with the best surface preparation, most paints don’t form a lasting bond with pebblecrete. It tends to peel, flake or wear away quickly under foot traffic, so I’m not aware of any paint manufacturer who specifically recommends painting directly over it.

Generally, the only long-term solution is to remove the pebblecrete entirely and then resurface the area with a product designed to be coated, such as plain concrete, a levelling compound, or a resurfacing product. Once you have a sound, porous surface, paints like Rust-Oleum or paving paints will perform much better and last as intended.

If you were set on attempting to paint over pebblecrete, the preparation would involve heavy-duty cleaning with a degreaser, followed by mechanical abrasion (such as grinding) to try to open up the resin and give the coating something to grip. Even then, adhesion is still hit-and-miss, and you’d likely find the finish won’t last.

In short: painting over pebblecrete isn’t recommended, and removal or resurfacing before painting is usually the only reliable way forward.

Please let me know if you have any questions.

Mitchell