I HAVE HAD WALLS AND A PATIO WITH STEPS BUILT JUST BEFORE THE COLD SNAP, NOW ALL THE CEMENT IN THE WALLS AND PATIO HAVE CRUMBLED OUT ON THE FLOOR, MY BUILDER SAYS HE WILL FIX IT BY SCRAPPING OUT THE SURFICE OF THE CEMENT AND USING SUB-ZERO CEMENT OVER THE TOP OF THE REMAINS INSIDE, WILL THIS BE O.K.
