Karl Dropping had a client who didn't realize that the vessel sink, wall-mounted faucet combination he installed lacked a stopper.

"It was in a bathroom that kids used. He wasn't pleased when he couldn't stop the water," Dropping says.

He says contractors should make sure their clients know this or, if they want a stopper, find a manufacturer that offers an operable rod with a lever under the sink. In this case, Dropping had to retrofit a special drain.