X0206 3 2017-08-01 1 0001574815 BMC STOCK HOLDINGS, INC. BMCH 0001212607 ALEXANDER MARK A C/O BMC STOCK HOLDINGS, INC. 980 HAMMOND DRIVE NE, SUITE 500 ATLANTA GA 30328 1 0 0 0 Exhibit 24: Power of Attorney /s/ Lanesha T. Minnix by power of attorney for Mark A. Alexander 2017-08-03