To put matters simply, concrete is a fairly temperamental building material. While finished concrete is known for its strength and durability, a lot has to go into its creation and application in order for it to achieve that final result.
The finishing process, in particular, can introduce a number of problems for inexperienced concrete users.
In the following guide, you’ll find a collection of tips geared towards this important final step in the concrete application process. Each of these tips has been tested and approved by concrete application experts, too, so you can trust their wisdom next time your work requires you to throw down some fresh concrete.
7 Concrete Finishing Tips and Tricks
Let’s jump right in.
1. Always Keep the Final Appearance in Mind
Now, this might sound like an obvious tip at first but bear with us.
You’d be surprised at how often DIYers and professionals alike get caught up in their work and forget that their concrete slab needs to take on a certain appearance once it is complete. As such, care must be taken throughout the finishing process to ensure that the final slab maintains its finalized appearance.
This is particularly true in the case of stamped concrete, which is intentionally modified during the finishing process to obtain a certain aesthetic design.
While the stamping may not occur until the tail end of the finishing process, it must be timed such that its design is not damaged by any other part of the finishing process. In short, foresight is a key ingredient to any concrete finishing task.
2. Trowel with Care
Troweling isn’t an easy job, to be sure. But that doesn’t mean that you should rush through it without considering how your technique will impact the finalized concrete slab.
In all cases, equal pressure should be applied while troweling to ensure undesirable grooves do not appear in your slab’s surface. This same premise applies to the use of a bull float or a magnesium float, as well.
Patience and care at this step can really pay dividends later on.
3. Work Bleedwater Back In
As your concrete begins to set, you may notice some amount of water rising back up to the surface. This is known as “bleedwater,” and opinions on what to do with it vary.
In most cases though, your best bet is to efficiently work that water back into the mixture before it is able to set. Otherwise, it may not have enough internal moisture to achieve the desired strength or density.
Alternatively, some concrete experts believe that it is worthwhile to allow this water to evaporate. You may choose this option if you are still seeing some water rise to the surface after an attempt to work it back in. This may be a sign of excessive moisture in the mixture to begin with, making evaporation of some of that moisture prudent.
4. Control the Finishing Environment
You should always put in the extra effort to control your finishing environment. Namely, you should avoid finishing concrete in an environment that lacks a flowing air current or access to direct light (ideally, direct sunlight).
These ingredients are crucial to getting your concrete to set correctly and cure as desired.
After all of your finishing steps have been taken, you should also be sure to pull a plastic sheet over your entire slab. This can help moderate the moisture evaporation process while also preventing debris from lodging in the still-malleable surface.
5. Place Your Control Joints Judiciously
Most concrete workers know the importance of placing control joints across their slab’s surface. However, there’s a lot of confusion about actual spacing with these indented grooves.
As a rule of thumb, these joints should be placed no further than 24x the width of the slab apart. So, a 1-inch slab, for example, would warrant control joints every 24 inches apart on its surface.
At the same time, don’t just freehand your control joints. Consider using a straight edge and lightly marking these all-important lines before placing a groove tool to the wet concrete’s surface.
6. Apply Sealant as Soon as Possible
If you are planning on applying a sealant to your new slab, don’t wait to do it. In fact, you should apply your chosen sealant to your target slab’s surface as soon as that sealant’s formula allows for.
However, not a drop of sealant should be applied until you have tested your new slab’s tensile strength at least once. That same surface should also be cleaned prior to application to prevent trapping debris on the slab’s surface.
7. Make Friends with an Edging Tool
You may feel like you already have enough finishing tools to keep track of. But if you don’t already have an edging tool available to you, you should invest in one immediately.
These tools look like a square trowel with a curved lip. In practice, their shape allows you to effectively create an edge where a bull float or magnesium float cannot reach. This consistent edge, in turn, is more durable against wear, as well as sudden impacts.
When you get down to it, there’s a lot that goes into proper concrete finishing. It’s no wonder that even concrete application specialists take years to master the craft.
While you may be a long way from that skill level, the tips and recommendations listed above should help you move toward that level of mastery in no time.
Be sure to try them out the next time you’re called upon to finish a freshly-poured slab.