Choosing supply lines for a clawfoot tub faucet can be a bit intimidating. This is especially true for tub wall mounted faucets. There are several different types of clawfoot tub supply lines for tub wall mounted faucets and within each type are several variations. It can be overwhelming initially but it needn't be. Today, we will tackle the bully of the clawfoot bathtub faucet shopping process with some basic tips for choosing the correct supplies for a tub wall mounted faucet.
Clawfoot tub faucets that mount on the bathtub wall have two threaded shanks (hot and cold) that extend through holes drilled in the wall of the tub. Most often the holes are drilled 3-3/8" on center but exceptions do occur. Usually, the shanks are threaded 3/4" IPS for tub wall mounted faucets but 1/2" IPS threaded shanks are also quite common. The rough-in connection for clawfoot tub supply lines is typically through the floor but can be through a bathroom wall in basement clawfoot bathtub projects. The rough-in is often, but not always, 8" centers. The supply lines connect to the shanks on the exterior of the tub and given the number of installation possibilities, it is easy to see why supply line selection gets complicated. At this point, you might be thinking that we're moving in the wrong direction in our attempt to simplify the selection of supply lines for your faucet. We'll get back on track in the next few paragraphs.
Double offset clawfoot tub supply lines are the best option for most tub wall mounted clawfoot tub faucet projects. The first offset in the double offset supply line bends 90 degrees to allow a tub wall mounted faucet to connect with a roughed-in through the finished floor. The second offset flares from 3-3/8" centers at the faucet connection to a common 8" center rough-in. Double offset supply lines include nuts and washers to connect with both 3/4" IPS and 1/2" IPS faucet shanks. Double offset clawfoot tub supply lines address the majority of clawfoot tub faucet installations and are certainly the recommended approach to new installations. If your faucet has 3-3/8" centers and the rough-in is through the floor at 8" centers, your project is normal and double offset supply lines are for you.
Like double offset clawfoot tub supply lines, single offset clawfoot tub supply lines curve 90 degrees to allow a tub wall mounted faucets to connect with a roughed-in through the finished floor. However, single offset supply lines do not have the offset for 8" center rough-ins. The rough-in centers must match the faucet centers. For example, if single offset supply lines are used with a 3-3/8" center faucet, the floor rough-in must also be 3-3/8" centers. Single offset supply lines include nuts and washers to connect with both 3/4" IPS and 1/2" IPS faucet shanks. Single offset supply lines are most frequently selected for clawfoot tubs that have faucet holes drilled at unusual centers (e.g. 4" centers, 6" centers, etc.).
The brass tubing for double offset and single offset supply lines is malleable. A tube bender can be used to make slight adjustments to the supply lines if the rough-in isn't perfect. A 90 degree turn for a rough-in through the finished wall is not considered "slight" however. If the supply lines for your clawfoot tub are roughed in through the wall, stainless steel braided flex hoses are the solution. Flex (as in flexible) hoses can be shaped to solve rough-in problems that can not be solved with either double offset or single offset supply lines. Flex hoses have a 1/2" IPS nut at each end that can connect directly to a 1/2" IPS faucet shank. Supply line elbows (or bathcock ells) are used with tub wall clawfoot tub faucets that have 3/4" IPS shanks. Supply line elbows have a 3/4" IPS faucet connection and reduce to a 1/2" IPS flex hose connection.
Shop 4 Classics recommends shutoff valves for the connection between the rough-in and the supply line. Shutoff valves (or stops) are recommended because they aid with installation and maintenance. Some double offset and single offset supply lines include 1/2" IPS shutoff valves while others offer them as an option.
Shop 4 Classics also recommends allowing 5"-6" between the tub rim and the wall for installation of double offset or single offset supply lines. In addition to the projection of the supply lines themselves, space will be required to accommodate the floor escutcheons. Squeezing the biggest tub possible into a space is a noble thought but ignoring the supply line connection may force you to choose flex hoses to complete installation of the faucet.
We've addressed every reasonable supply line possibility for clawfoot tub faucets mounted on a tub wall but clawfoot tub faucets can also be freestanding, installed on the tub rim, or mounted on the bathroom wall. These configurations introduce several more variations of supply lines as well as one configuration that does not require supply lines of any kind. We'll get to these configurations in future posts to the Shop 4 Classics Old House Blog.