Broom finish concrete is better known as “brushed concrete”, but the broom is more to the point: basically, after the concrete is poured and levelled, it’s gone over with a stiff broom to give it a rough surface. This is opposed to finished concrete, which has a smooth surface.
It’s a very affordable, low-maintenance way to give your concrete driveway, walkway, staircase, and patio a little design, but it serves a greater purpose: it gives extra traction to the concrete. You’ll want this added bonus around pools to prevent slips and falls. Making broom finish designs is not a difficult process, either!
How To Broom Finish Concrete
The concrete is poured and “screeded”, which means the excess wet concrete is cut off to bring the proper grade and smoothness to the top surface of the concrete. A “ float” is then used to make the surface smooth, removing imperfections and compacting the concrete. The float blade must be kept as flat as possible and in full contact with the surface of the concrete as it smooths it out to avoid densifying and sealing the concrete.
Now, we wait for the evaporation of excess water, which comes out as the concrete settles. Under the proper temperature conditions and with a low water/cement ratio, there might not be a lot of bleed.
Next, you might see a finisher go over the slab with a trowel. If the concrete is getting brushed, some finishers might be satisfied using a float before the broom, but a trowel can smooth out any potential float lines in the concrete. Whoever is doing the work should be careful not to go overboard with a trowel finish, however, because overworking the surface can solidify it, making it difficult to get the proper texture with a broom.
Now comes the fun part: brooming the surface. This is done by running a stiff-bristled broom perpendicular to the potential slope of the concrete; if the concrete needs to drain, the brush marks should be run towards the drain. Brooming won’t hurt the integrity of the material, and your brushed concrete will be just as strong as finished concrete.
Of course, you’ll only get this strength by curing the concrete. This is an incredibly important step that provides the concrete with the right levels of moisture and the optimal temperature so that the concrete develops the hardness it needs to last under pressure. Curing uses either a sprayed-on compound or sheets of polyethene. For the curing spray, you’ll normally see colour that can help the worker tell where it has been applied – don’t worry, the colour will go away in a matter of weeks.
Can I Use Any Broom For The Effect?
If you are doing the brushed concrete effect yourself, don’t worry about having to invest in a special broom. You shouldn’t just use any broom, but as long as you have a clean push broom with stiff bristles, you should be fine. There are special concrete brooms, but they aren’t necessary. Just draw the bristles across very lightly, not applying too much force, and make sure it’s clean before putting it back into the concrete. Contact us to learn more about broom finished concrete.