Right, this stuff’s called ARDEX P 51, and it’s basically a fancy blue liquid that helps other materials stick properly. You slap it on before levelling floors, tiling, plastering, or smoothing things out.
It’s water-based (so no nasty smells or solvents), and that bright blue colour isn’t just for show — it helps you see where you’ve already painted it on. Handy, right?
It also stops those annoying little air bubbles popping up through your floor levelling mix, and helps everything spread nice and smooth.
You can water it down depending on what you’re priming — about 1 part primer to 1 part water for normal concrete, or 1 to 5 if your surface is super thirsty. If the concrete’s really dense or shiny, use it thicker or even straight out the bottle for better grip.
Brush or broom it on, let it dry, and it’ll turn into a clear blue film ready for your next layer. It can even double as a dust protector if you’re waiting to finish things off.
Just make sure the floor’s clean, dry, and above 5°C — because cold, wet muck won’t stick to anything properly.