Dimension diagram of a round Calacatta Viola marble sink with length, width, height, drain hole and weight

How to Measure for a Marble Sink

August 29, 20263 min read

Almost every problem we hear about after delivery is a measuring problem, not a stone problem. A basin arrives, it is beautiful, and it is two inches too deep for the vanity. Stone cannot be trimmed on site, so the measuring has to be right before production starts.

Here are the five measurements that decide it, in the order we would take them.

1. The wall run

Measure the clear wall where the basin will sit, from one return to the other, at the height the basin will be. Then subtract at least four inches at each side. A basin that touches a side wall or a door architrave looks like a mistake even when it fits, and it makes cleaning around the rim awkward.

Our sinks run from 15.7 to 40 inches wide. If the clear wall is under 30 inches, work from the compact range rather than trying to squeeze a 24-inch basin into the space.

2. Projection

Projection is bowl depth plus tap projection, measured out from the wall. This is the number that people bump into, literally. In a cloakroom or a narrow bathroom, 16 to 18 inches of total projection is about the limit before the basin starts to obstruct the route past it.

Bowl depths in our range run from 14 to 18 inches. On a 20-inch deep vanity, anything past 16 inches leaves no counter in front of the bowl.

3. Rim height

A counter-top vessel bowl adds its full height to whatever it stands on. Our vessel bowls sit 4 to 6 inches proud, so a standard 32-inch vanity becomes a 36 to 38 inch working height once the bowl is on it. That is comfortable for an adult and too high for a child.

A vessel bowl on a 36-inch kitchen-height counter is almost always too high. If the counter is already tall, look at a wall-mounted basin instead, because you can set its height wherever you want it.

4. Tap clearance

Two numbers matter here. The spout has to clear the rim by at least two inches so you can get your hands under it, and the spout has to reach far enough over the bowl that water lands near the centre rather than on the back wall of the basin.

Most standard basin taps are too short for a vessel bowl. Either use a tall vessel tap, or move to a wall-mounted spout, which also frees up the counter behind the basin. If you are deck-mounting the tap on a vanity top, leave three inches of counter behind the bowl for the tap body and the escutcheon.

5. Waste position

Our basins take standard 1.5-inch pop-up wastes. Most are supplied without an overflow, which matters more than it sounds: a slotted waste is designed to work with an overflow, so on a basin without one you want a click-clack or a free-flow waste instead.

Measure the horizontal distance from the wall to the centre of the drain on the basin drawing, then compare it with where the trap actually sits in your wall or floor. On a wall-hung basin this has to be resolved before the wall is boarded.

If the basin is wall-mounted

Add one more check. Wall-mounted stone basins are carried by a bracket, and the bracket has to reach something structural. Timber studs, a steel frame or a plywood pattress fixed across two studs are all fine; plasterboard fixings on their own are not, and no amount of resin anchor makes them fine.

Our brackets come in sizes from 8 to 32 inches to match the basin width, and they are sold separately from the basin. Decide the mounting method early, because on a wall-hung installation the pipework, the bracket backing and the finished wall all have to be planned together.

Write the numbers down before you order

Clear wall run. Total projection. Finished rim height. Spout clearance and reach. Drain centre. Five numbers on a piece of paper is enough to check any basin in the catalogue against your room in about two minutes.

If none of the standard sizes work, that is what the custom route is for. Send the same five numbers with a sketch and we will quote a piece that fits.