Q: I am new to woodworking but pretty good at building other things. I am building (or rather re-building) a large pantry cabinet in my kitchen, and I want to make sure it holds together this time. I thought about using a biscuit and dado for each joint. Is this advisable and, if so, how would I go about creating a biscuit slot within the dado?
A: While the concept of reinforcing a joint is not out of the ordinary, adding a biscuit to a dado joint is one I’ve never heard of. It is common to reinforce a long dado joint with nails or screws (often taking the place of clamps when building the joint) but not biscuits. There are a couple of reasons for this: first, biscuits will not strengthen the joint. A well-made dado joint is remarkably strong, so adding the biscuit would simply introduce a degree of complexity with no clear benefit. Second, it would be tricky to get the biscuit slot cut into the bottom of a dado — not impossible, just really, really complicated. (After which I refer you back to my first point.)