From Longman Dictionary of Contemporary Englishsupporting wall/beam etcsupporting wall/beam etcTBBSUPPORT/HOLD UPa wall etc that supports the weight of something → supporting
Examples from the Corpus
supporting wall/beam etc• There was a portico, generally of wood, with posts supporting beams, and decoration was in terracotta.• The roof was in an appalling state and the supporting beams were rotten. 