Every hanging job starts with the same question: what is this wall? Gypsum partition takes self-drive plasterboard anchors happily for light frames, up to roughly five kilograms per point, and spring toggles or metal cavity anchors for heavier pieces; anything genuinely heavy, a large mirror, a floating shelf meant to carry books, should land on the metal studs. Solid block or concrete takes standard nylon plugs and holds almost anything, the only cost being a hammer drill and some dust management.
The surprise is hollow block, common in older and mid-market buildings across the northern emirates and in plenty of Dubai and Sharjah stock from the 1990s and 2000s. The drill punches through the block face into a void, the plug spins uselessly, and an inexperienced installer just moves over ten centimetres and tries again, leaving a trail of holes. The correct answers are longer plugs that grip the far face, umbrella-style cavity fixings, or for heavy mirrors and cabinets, a chemical anchor with a mesh sleeve that mushrooms resin inside the void. This is exactly the kind of judgement you are paying a professional call-out for.