Where Hard Trowel Finish Makes Sense and Where It Doesn't

Summary:

Cesar describes hard trowel as producing a smooth, dense, tightly closed surface, and he is clear about where it belongs. Interior applications are its natural home: garage floors, shop floors, and basement slabs, where a clean surface is easy to sweep and maintain, where the floor stays dry, and where a coating may be applied later. Outdoors in western Washington, he considers it the wrong choice for the same reason he steers homeowners away from exposed aggregate. A closed surface offers nothing for traction, and in a climate where surfaces stay wet much of the year, that becomes a safety problem. His rule is simple: hard trowel where it's dry, texture where people walk outside.

Answer:

Hard trowel gives you a smooth, tight, dense surface. It's a finish where the concrete gets worked more and the surface closes up on itself. Where that makes sense is inside. A garage floor, a shop floor, a basement floor, somewhere you want something clean, easy to sweep, easy to keep up, and somewhere that stays dry. It takes a coating well too if somebody wants to do an epoxy later. Where it doesn't make sense is outside in this climate. That surface has nothing on it to grab. As soon as it gets wet, and here it's wet a lot of the year, it's slick. It's the same reason I steer people away from exposed aggregate for a walkway. I don't want somebody slipping on a surface I put in the ground. So for me it's a simple rule. Inside where it stays dry, hard trowel is a good finish. Outside where people are walking and it rains, I want texture on it, and that means broom.