The quality of the concrete is one of the most important things when fixing Tapcon screws. So how long should concrete cure before Tapcon screws can be effectively used for your project?
It is recommended that the concrete be completely cured before fixing Tapcon screws. This gives them the best chance of establishing a successful fastening. Complete curing typically takes 28 days.
Does Concrete Have To Completely Cure Before Using Tapcons?
So that you are sure that your Tapcons will work well, the concrete should be completely cured. The entire curing process takes about a month, but it is possible to walk or drive on the concrete before this time.
Each work project is different, so the particular works need to be considered before you decide when to use Tapcons in your concrete.
The material that you are fixing to the concrete as well as the type of concrete used will influence the cure time. This includes the material’s size and purpose. A major factor is the weather and how it can affect the curing times.
When you decide to use Tapcons in concrete it is important to think about the following timings:
- 24–48 hours – after initial set, the forms can be removed, and you will be able to walk on the surface of the concrete
- 7 days – after partial curing it is ok for traffic from normal vehicles and equipment to be used on the concrete
- One month – after this point the concrete will be fully cured
What Affects Curing Times For Concrete Before Using Tapcons?
There are several things that affect the length of time that concrete should cure for. All of these factors will affect when you can use Tapcon screws in your concrete.
The mixture proportions of the concrete will have an impact on the curing time of the concrete. Quick drying mixtures will cure faster than others. They will need certain techniques to mix and pour them properly.
The advised strength of the concrete will depend on the structure or use to which the concrete is being put. It is measured in compressive, tensile and flexural strength.
Size & Shape Of Concrete
How long it will take concrete to cure will depend on the size and shape of the concrete. This also affects how long before you can use Tapcons.
Ambient Weather Conditions
How hot, cold, dry or windy it is will directly affect the cure time of concrete. This can be crucial to the concrete curing properly. The concrete needs care and attention for the first week at least.
Future Exposure Conditions
Concrete continues to cure even after it has dried and hardened. For this reason remember future exposure conditions will affect how soon Tapcons can be used.
Curing Vs Drying
When you are dealing with concrete it is important to understand the difference between curing and drying. These terms are often used interchangeably but mean very different things.
A slab of concrete may be dry enough to walk on after 24 – 48 hours but will not be cured completely for around a month. This should clearly show the different processes that are going on.
Curing is the name for the chemical changes which go on inside the concrete. in the days and weeks after it has been poured. This process gives the concrete its physical properties.
When cement is mixed with water, rock-like crystals grow and join together giving the concrete strength. For curing to happen the moisture content and temperature must remain in the right range.
Extremes can either speed up the curing and cause cracking and weakness or stop the curing process altogether. Neither is desirable.
After 7 days concrete is typically cured to 70% of its specified compressive strength. This is probably enough to use Tapcon screws in the concrete. Some people may prefer to leave the concrete to cure for 14 days before trying to drill into the surface.
If you drill too soon into concrete to fit Tapcon screws you may risk spalling the concrete. This can be a particular risk if you are drilling close to the edge of the slab or structure.
How To Install Tapcons Into Concrete
- Choose a Tapcon screw that is the correct size, head type and length for what you need. The thickness of the material you are attaching to the concrete will determine the length of the screw.
- Mark the spot where the Tapcon will be going.
- Most Tapcon screws come with a specific bit that is the correct size for that particular size. Attach the bit to your drill and turn off the hammer feature.
- Holding the drill bit against the hole, turn the bit slowly to get grip in the concrete. Make sure the drill is held perpendicular to the surface.
- Turn on the hammer feature of the drill and make the hole for the Tapcon. Make sure that the dust from the hole is cleaned out so that it doesn’t interfere with the fitting of the Tapcon screw. The hole should be half an inch longer than the screw to allow for any remaining dust to fall into.
- If needed drill a hole in the material to be fixed to the concrete. Skip this if the item already has holes for fastening.
- Drive the Tapcon screw through the object being attached. Use the driver feature of the drill with the appropriate shaped bit for the screw head.
- Once the screw is almost in you can use a socket to make the final turns and ensure the fixing is in securely.
The holding value of the Tapcon screws depends on the quality of the concrete that it is being fastened to. That’s why it is important to make sure that the concrete is cured for at least two weeks, but a month is better if possible.
Allowing concrete to cure for 28 days will give you the best chance of a successful fastening with Tapcon screws.