problems with buttermilk biscuits
In quick breads, as opposed to yeast raised breads, it gelatinized starch that creates the structure of the bread, and holds the leavening.

However, according to my research, most spelt flour (which is in fact a variety of wheat) is whole grain flour, so the bran will interfere with structure development.

My quick research indicates that spelt flour recipes requires less liquid to hydrate than standard wheat flour.  According to What's Cooking America, this is because spelt flour is more water soluble than standard wheat flour (I interpret this to mean that the starches in it are).  

If you google "spelt biscuits" you will find a variety of recipes that are tuned to its characteristics, such this one from All Recipes or this one from King Arthur.