Broom Finish a Concrete Slab
How to apply a non-slip broom texture to a concrete slab
1. Use a good broom
David uses a horsehair/nylon combination broom with a long extension handle. Brooms are also made with polypropylene of various stiffness. A plastic block will not warp over time as a wooden one will.
2. Finish at the right time
The tricky part is finishing the surface at the right time. On the slab in the video, there was fluctuation in the curing time because of different substrates under the slab and different exposure to sunshine.
"You have to finish everything as it dries; it is all about timing.
You have to be on time all the time. That's how concrete operates."
David and his crew jumped around the house brooming sections of the slab as they were ready.
Before brooming, some people trowel with a magnesium trowel, others do not. In this video, David does not.
If concrete starts to pile up in front of the bristles as you push or pull, it is too early. Smooth out the area with a magnesium trowel and wait.
After brooming, you may need to go over edges and joints again.
3. Brooming technique
If traction is the goal, run the broom perpendicular to the slope, if there is one. If drainage is the goal, run the broom in the direction of the slope. Push the broom to the wall or to an expansion joint and then pull it straight back.
Regardless of the direction, use slow, smooth, straight strokes. Aim for straight lines.