The Distance Between Double Wash Basins in a Bathroom

Most homeowners would agree that two wash basins are better than one in a master bathroom. If you are installing double wash basins, you need to take some specific constraints into consideration in deciding how far apart the sinks should be.

Maximum Distance
Exceeding the maximum distance allowed between double wash basins in your bathroom may lead to drain problems later. If you buy a prefabricated lavatory setup from a home-improvement center, the wash basins should already be close enough together. If you are creating a custom setup, keep the wash basin drains within 30 inches of each other, according to Leslie Plummer Clagett of "This Old House."

Height Considerations
In addition to measuring the distance between the wash basins, you need to consider the height of the vanity top. Make sure the new vanity does not sit more than 6 inches higher than the old one.

Shared Drains
The drains from your double wash basins feed into the same stub-out, or the drain pipe that goes into the wall below the sinks. Since the wash basins both drain into a single pipe, you only need to install one trap piece onto the stub-out. How you configure the pipes under the wash basins depends on the location of the stub-out in relation to the two drains. If the stub-out sits between the drains, you must attach a tee to the top of the trap and attach the drains to the two open connections on the tee. If the stub-out sits closer to one drain, you must install a tee on the closer drain to connect with the further drain.

Space Constraints
The size of the bathroom must also be considered when figuring how far apart to place the wash basins. The vanity must not obstruct pathways or doors as they swing on their hinges. The configuration of the bathroom may force you to place the wash basins closer to each other than you planned.