VB-02Confirm your wall is solid brick or blockThis guide is for solid masonry only. Tap the wall firmly with your knuckle: a solid, dull thud means brick or block, while a hollow sound means a stud wall or dot-and-dab, which need different fixings. Drill a small 5mm test hole in an unseen spot; brick dust confirms masonry, but timber dust or fine steel swarf means you're actually into a stud, and this method won't hold a vanity unit safely there. If your wall turns out to be stud, dot-and-dab or lath and plaster, stop and follow guidance for that wall type instead.