Builders' rhymes with:
builder's, builders, rebuilders, bewilders, builder's, builders, childers, gilder's, guilder's, guilders, rebuilders
Builders' sounds like:
balderas, baldric, baldrige, balladur's, beladur's, bellwethers, bewilders, bladders, blowdries, blowdryers, blowtorch, blowtorches, boulders, builder's, builders