Yes, you can install composite decking over a concrete patio, as long as the concrete is in good condition and even. Here are the steps you can follow to install composite decking over concrete:
Clean the concrete surface: Sweep the concrete surface to remove any debris or dirt.
Level the concrete: Check the concrete surface with a level to make sure it is even. If there are any low spots or uneven areas, you may need to use a self-leveling compound to smooth them out.
Install framing: Install pressure treated timber, aluminium or composite framing over the concrete surface. Make sure they are spaced no more than 400-450mm apart and parallel to each other.
Attach the framing: Use concrete screws or adhesive to attach the framing to the concrete surface if level or use pedestals or similar if extra height or levelling is required.
Install the composite decking: Once the framing is in place and is solid and level, you can start installing the composite decking. Use composite decking clips to attach the decking to the framing, making sure to leave the necessary gap between the boards for expansion and drainage.
Finish the edges: Install fascia boards or trim pieces around the perimeter of the deck to finish the edges and conceal the sleepers.
Keep in mind that installing composite decking over concrete may raise the overall height of your deck, which could affect access to doors or stairs. Additionally, if the concrete surface is cracked or uneven, it may not be suitable for installing composite decking. Always consult with a professional if you have any doubts about the suitability of your concrete surface for this type of installation.