You can seal existing concrete at any time and on multiple occasions. Sealing your old concrete can assist in restoring its appearance. For existing slabs, make sure to clean the surface before applying another sealer.
Sealing your concrete not only ensures your concrete surface is protected, but that it is long lasting. It should also be noted that compared to the cost of replacing a concrete surface, sealing is relatively inexpensive and easy to do–definitely worth a long lasting concrete floor, patio, slab, or driveway.
Before applying a new sealer, it's very important that you make sure the old one is completely gone. This is because any old sealer left on the surface of your concrete can impede the effectiveness of the newly applied sealant, preventing proper adhesion to the concrete surface.
It's Never Too Late …
Sealing your garage floor might not be possible if you have moisture in your garage. This is typically the only scenario where we don't recommend sealing right away, mainly because you should deal with the cause of the moisture first. It could be due to a plumbing leak or a drainage issue.
However, if the concrete is dirty and has not been cleaned, then the concrete sealer will not bond to the surface of the concrete. It will instead bond to that dirt, if it bonds at all, leaving the concrete vulnerable to all kinds of potential problems.
Make sure the surface is clean. Wipe up all oil and grease spills. Sweep and scrape away all dirt and loose contaminants with a broom. If the surface is new or uncoated, use a product to clean and etch the surface.
Do you have concrete foundation that is crumbling and flaking? Some causes may be due to freeze-thaw cycles, drought and rain cycles, and shifting foundations. A way to prevent this is with the use of a penetrating concrete sealer. It is one of the most cost-effective ways to prevent crumbling and flaking.
Concrete, like any other porous surface, is best when it is sealed. You can seal concrete with a chemically reactive penetrating sealer, acrylic–resin sealers, and highperformance topical coatings, such as epoxies and urethanes.
You can fix spalling — a patchy and pitted surface — with a concrete resurfacer and patch small pits and cracks with a concrete repair mix. While a resurfacer contains bonding agents that allow it to bond to the concrete, you'll need to apply a scratch coat or liquid bonding agent before using a repair mix.
The answer depends on the surface's square footage. For large surfaces such as commercial floors, a sprayer is faster and way more efficient. Finally, for small surfaces, such as garages or any other exterior surface, a paint roller or any other type of roller will do the trick. Rolling is a less expensive process.
In short, yes, sealing concrete will change the appearance of your concrete. Leaving concrete unsealed will leave it with a flat look.
You MUST profile the concrete prior to sealing. The BEST results are from hand wet-sanding (option 2) or machine honing (option 3) to 200 grit, and then acid etching (option 1).
Sealer needs to be applied in dry conditions because it won't adhere to damp concrete. The temperature also needs to stay above 50 degrees Fahrenheit during application and drying, which can take up to three days.
Remove all loose material with a small paint scraper, then brush off the dust. You can use packaged masonry or concrete repair mixes, available at home improvement stores, or buy a bottle of concrete bonding agent and a bag of mortar. Brush the bonding agent onto the old concrete and let it sit until tacky.
Concrete seems like a stable and permanent material, but it remains porous and will absorb water. When this water trapped inside the concrete freezes, it pushes the cement binder apart. This expansion, and the resulting contraction when the water melts again, causes crumbling.
Acrylic Concrete Sealers: Acrylic sealers last 1-3 years before they need to be re-coated. Epoxy Coatings: Epoxy coatings last 5-10 years before they need to be re-coated. Urethane Coatings: Urethane coatings last 5-10 years before they need to be re-coated.
The other benefit to sealing concrete is improved cleaning and maintenance. Sealers prevent spills and debris from staining the surface and make it much easier to clean. They also enhance the surface and depending on the type of sealer chosen, a natural matte finish or rich colour can be achieved.
Outdoor concrete sealers are not only worthwhile but necessary. Experts who recommend having a concrete surface sealed are doing their customers a big favor. Without this extra layer of protection, concrete will absorb moisture and may begin to crack, spall, flake, and discolor, among other things.
When the sealer is applied too heavily, the air displaced through the surface can't escape, and it forms a bubble in the sealer surface. Bubbling of a sealer can also occur if application is done in hot weather, or if the concrete is in direct sun.
The culprits of blotchy concrete after sealing
When you find yourself staring at discolored concrete that has already been sealed, there are usually three potential sources of blame: The sealer was applied poorly. Not enough sealer was applied. The concrete itself had varying absorption rates.