Attention, friends planning to install frameless downlights! Without prior preparation, you might encounter some trouble. We purchased recessed downlights with pre-embedded parts, choosing a round, full-edge model, but we didn't thoroughly research the installation method.
The carpenter wasn't sure either, directly fixing the pre-embedded parts to the wooden blocks within the plasterboard. The designer hadn't installed recessed downlights before, leading to problems during puttying.
The pre-embedded area protruded, making it difficult to plaster evenly; plastering it flat resulted in bulges around the downlight. To flatten it, a large area had to be re-leveled according to the downlight's thickness, which the plasterer was unwilling to do, saying the putty was too thick.
Later, we searched for recessed downlight installation methods on Baidu and discovered the problem lay in the pre-embedded parts installation. The correct method is: first, use a countersunk hole saw to drill holes according to the spotlight's location, then use flat-head rust-proof screws to fix the pre-embedded parts to the wooden blocks, ensuring the pre-embedded parts are flush with the plasterboard.
Don't make the same mistake we did, ending up having to remove the embedded parts and replace them with surface-mounted lights. For detailed instructions, you can search for relevant tutorials to avoid similar problems.