Align edges of two lines (not centers)

Probably a simple way to do this but I can't find it.  I have two line segments of different thicknesses.  I want the thicker line to align to the top edge of the thinner line. When I use "align top", they align to the center of the lines.  I want them overlapping, flush to the top edge. I also tried snap options without success. Any help would be appreciated.