Before any architectural concrete work is started a mock-up of a typical section preferably full size should be constructed and finished. Actual construction should not begin until the quality and appearance of the mock-up have been approved by the architect and the owner. SMOOTH SURFACES After the forms have been stripped from smooth vertical surfaces a grout cleandown or patching may be required. Tie rod holes and air pockets (bugholes) may need filling; any honeycombed or flow-line areas will need patching. Preparing surfaces for patching and cleandown may be done at any time, except that large or deep holes should, if possible, be filled a day or two before the actual grout cleandown. Snap ties should be broken off at least 1 inch behind the surface. If they are broken off closer than that, rust stains will eventually occur. If ties are not broken off carefully chiseling may be necessary. All burrs and fins should be chipped off with a sharp brick hammer or with hammer and chisel. Honeycombed areas should be chipped back to solid concrete. Uneven joints should be bushhammered. Wherever necessary, laitance or dusting surfaces should be removed by brushing or stoning by hand or machine. If a power grinder is used, be careful not to make any part of the surface very smooth or polished. Materials like oil stains, form coatings and keel marks that will adversely affect the grout bond should be removed. Finally, the surface should be thoroughly soaked at least 15 minutes before the grout application. If the surface is not moist enough it will rob the grout of its water, making good bonding questionable and interfering with curing.