Q: We are selling red elm products, including flooring. We have used some data to show that this wood is nearly as hard as oak. But a recent customer indicates that the wood is quite a bit softer than he requires. Any idea what is going on here?

A: American elm (Ulmus americana) and red elm (Ulmus rubra) are two soft elms that are only 60 percent as hard as oak. The other elms, such as slippery elm and rock elm, are called hard elms and indeed are as hard as oak. So, the problem is in the definition or name of the wood you are using. Red elm lumber can actually be used to refer to several different hard and soft elm species.

We have this confusion with other species. Red oak lumber includes more than 20 species of wood, with some species varying quite a bit from others. Hickory lumber includes eight species of wood, four of which are really pecan!

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