Concrete Cure & Seal. I have so far failed to understand why so many homeowners and contractors believe that curing the concrete faster will extends the life of the concrete. I am here to trump that rumor and I plan on doing it with scientific facts. Before I begin, sealing concrete is very important – but the most effective way to seal concrete is after it has had a chance to cure.
Why shouldn’t I increase the cure rate of concrete? Concrete hardens as a result of hydration: the chemical reaction between cement and water. Most curing compounds will seal in the moisture that is already present. With this process, three things could happen: 1) Because the water has no way to escape, the concrete must absorb the trapped water – all of it. This can cause something called “expansion.” 2) Once sealed, water can penetrate throug the surface coating so if you don’t add enough water to the concrete mixture, it will cause something called “shrinking.” 3) Lastly, if you pour concrete and the temperature drops, the water trapped in the pores of the concrete will freeze and cause the freshly poured concrete to crack and spall.
It cures and seales, so won’t the sealer help? No. Any sealer manufacturer will advise you never to seal concrete until it has completely cured (27-29 days). The concrete is still filled with water and hasn’t had a chance to fully harden. If you apply a surface sealer too early, it may not adhere to the concrete. If you apply a penetrating sealer too early, it won’t properly penetrate the concrete and could become over-diluted because of the amount of water already present.
What should I do? Wait until the concrete has cured, 27-29 days, and apply the Foundation Armor concrete sealer. The Foundation Armor concrete sealer penetrates deep into the concrete. The silicate reacts with the free lime to form a crystalline barrier within the pores of the concrete. As a result, the concrete is strengthened by up to 45% and stops water, vapors, moisture, radon, and efflorescence. Apply it once in a lifetime. It will never weaken, peel, flake, or fade.