A pedestal sink installs by mounting to your bathroom wall, and it won't always line up with your studs. In order to hold the sink in place on the wall, you need some sort of mounting mechanism or bolt. Most sinks come with their own hardware but sometimes you'll find the hardware isn't enough.
Mounting Pedestal Sinks
Since most sinks will not line up with the wall studs, due to their placement in the bathroom, alternative methods of mounting the sink to your wall are necessary. One of those methods is using a drywall anchor, a plastic sleeve that houses the screw to mount the sink. This drywall anchor inserts into the wall before the sink-mounting bolts. The bolts are driven into the anchor and as they enter the anchor it expands to secure the sink to the wall. Since the anchor expands, it will brace the sink to the wall, but it is not always the best method.
Anchor Qualities and Drywall
Installing a pedestal sink with a drywall anchor is really a choice the owner must make. Drywall anchors will provide substantial holding power, but their durability and holding power is really relative to the strength of the drywall. If the drywall crumbles or gets wet, the anchor can pull right out of the wall. This causes the sink to wobble and become loose. Only if you feel the anchor is stable enough should you attempt to use it on your sink.
Proper Pedestal Sink Mounting
The proper and most effective way to mount a pedestal sink is to install a thick, backing board on your wall framing. A 2 by 6 board is normally screwed into the wall frames and the sink is mounted to this. Special mounting bolts are normally installed in the board and they pop out through the drywall to latch onto the sink-mounting holes. Then the mounting nuts are installed.
Choosing Drywall Anchors
If your sink has a rudimentary mounting system with no hardware, drywall anchors may be one option. However, you might find that mounting at least a 2 by 4 board behind the sink, and driving the screws into this is a more stable choice. If your sink mounts with bolts, rather than screws, drywall anchors are not an option, because the anchors require screws in order to expand properly.