I occasionally get an architect that wants the exposed concrete walls to be “sack and patch” for a smooth uniform finish. Does anyone have a source of language for this procedure? Thanks.
I think they want an ACI 301 Grout-Cleaned Finish.
David, Below are ACI finishes. I agree with Liz, that it sounds like they want a grout-cleaned finish.
Smooth-Rubbed Finish: No later than one day after removing forms, wet and rub surfaces to
produce uniform color and texture, using the cement paste created by the rubbing process.
Grout-Cleaned Finish: Wet surfaces and apply a sand-cement grout that will match the color of
the concrete. Fill voids, removing excess grout. When grout whitens, rub surface and keep it damp
for 36 hours. This is sometimes called a sack-rubbed finish.
Cork-Floated Finish: Wet surface and apply a stiff sand-cement grout that will match the color of
the concrete. Machine-grind grout into voids and cork float with a swirling motion.
I’ve found that this absolutely has to have a sample panel at the job site. Every contractor is going to assume that whatever they did on the last job is exactly what you want – whether it is, or isn’t. Find some hidden location like a storeroom wall or under the stairs and have them do a 3’ x 3’ sample of their finishing technique.