Responsible for the polymerization of the main chain of the major teichoic acid by sequential transfer of glycerol phosphate units from CDP-glycerol to the disaccharide linkage unit. Synthesizes polymers of approximately 35 glycerol phosphate units in length. 4-O-[(2R)-glycerylphospho]-N-acetyl-beta-D-mannosaminyl-(1->4)-N-acetyl-alpha-D-glucosaminyl di-trans,octa-cis-undecaprenyl diphosphate + n CDP-glycerol = 4-O-{[(2R)-1-glycerylphospho](n)-(2R)-1-glycerylphospho}-N-acetyl-beta-D-mannosaminyl-(1->4)-N-acetyl-alpha-D-glucosaminyl undecaprenyl diphosphate + n CMP + n H(+) kcat for CDP-glycerol is 14 min(-1) (PubMed:16141206). kcat for lipid III analog is 26 sec(-1) (PubMed:18465758). Optimum pH is 8. Cell wall biogenesis; poly(glycerol phosphate) teichoic acid biosynthesis. Positively regulated by WalR. Mainly expressed during exponential growth and rapidly shut off as cells enter the stationary phase. Belongs to the CDP-glycerol glycerophosphotransferase family.