Abstract
A chiral four-state clock-step model is introduced to describe the deconstruction and roughening of missing-row-reconstructed (110) facets of fcc crystals. Unlike simple cubic (110) facets, a reconstructed rough phase is absent. Roughening induces a simultaneous deconstruction transition, which at zero chirality has central charge c=1.5 and both Ising and conventional roughening critical exponents. Pt(110) and Au(110) are suggested as realizations of this at small chirality, where this transition has the character of an incommensurate melting transition into a rough incommensurate missing-row fluid.