Cast iron clawfoot bathtubs with a porcelain finish originated in the mid-1800s, according to Bob Vila, home-improvement expert. These tubs enjoyed a period of popularity until around 1920. Dating an antique tub requires a little know-how, so do a bit of research if you are planning to either sell or acquire one. Prices for these tubs may vary depending on where you live. Condition is another factor to consider because restoration is hard work and very time-consuming, and will impact the price.
Look for a manufacturer's name or logo. This could be anywhere inside or outside of the tub, depending on where it was made. This information will be helpful, but determining the actual age of a tub is an imprecise endeavor at best.
Look at the underside of the tub for a mold number. If you don't find one, search around the faucet and spigot fixtures and on the inside of the clawfoot. A mold number will help you find out who the manufacturer was, which will help you date the tub's approximate year of origin.
Check the tub's rim. Clawfoot tubs were mass-produced during the late 19th and early 20th centuries. The rolled rim was the most common and least-expensive type made. Originality of design does not necessarily mean the tub is older, but says that it cost more to make and was likely found in the home of a well-to-do family.
Determine if there is anything unique about the design or if the color is other than white. Unusual designs and colors are more traceable through an antique dealer or in antique books. Tubs with contoured sides are a rare find and are more valuable, while even-sided tubs are much more common.
Go online and visit websites that discuss vintage tubs. Try to find a picture of the type of tub in question and see if the feet appear to be original. This will further help you date the tub. A clawfoot may have been replaced, and this may indicate your tub is older. However, tubs that have had the feet replaced are considered worth less money due to the possibility of structural damage during replacement.