Leaving concrete unsealed will leave it with a flat look. The color will remain flatter and dull, in addition to the concrete remaining porous and easier to damage. Sealing the concrete will enhance the colors and give it more of a marble or mottled look, smoother and with richer colors.
While you do not strictly need to seal your acid stained concrete, we strongly suggest doing so. Applying sealer will help maintain the appearance of your stained concrete. You can apply sealer once the stain has been neutralized, rinsed well and the surface is completely dry.
We recommend that all types of exterior concrete should be sealed including plain concrete, exposed aggregate, stamped concrete, stained concrete, integrally coloured concrete, stencilled concrete, engraved concrete and overlays.
Apply Finishing Sealer
Concrete sealers protect the finish of your stained concrete. Test before application. Use clear sealer to enhance the depth of color and to repel dirt, water and environmental wear. Choose a concrete sealer that offers the right amount of gloss and durability for your needs.
Concrete should be sealed to protect from mold and mildew.
Because concrete is a porous material, it has a tendency to absorb moisture. When this moisture doesn't dry and the surface is left wet for an extended period of time, mildew begins to form and mold begins to grow.
When you don't finish concrete floors, many things can occur such as wear and tear in high traffic areas, unwanted and unsightly cracks, higher associated costs, increased cleaning and maintenance, and water retention.
If your concrete is new, you'll need to let it cure; wait at least one month before applying sealer. Before you apply it, check the weather. Sealer needs to be applied in dry conditions because it won't adhere to damp concrete.
Few materials have the longevity of concrete. And because stains permeate the concrete to infuse it with permanent color, a stained concrete floor or pavement should last a lifetime when properly maintained (see How to Protect and Maintain Stained Concrete .
Sealers, particularly solvent-based sealers, will darken concrete. If unevenly applied, it will create light areas where there is less sealer, and darker areas where there's more. If applied by sprayer, it may appear like “stripes”. Uneven roller application may leave darkened roller marks.
Epoxy floors and polyurethane coatings will provide better chemical resistance and overall durability in these applications. Polished concrete floors generally cost $4-10+ a square foot to install, while grind and seal concrete floor installations can be as low as $1 a foot. Keep in mind that these are upfront costs.
Stamped concrete can fade over time due to exposure to the elements and lack of proper maintenance. If an adequate exterior seal is not applied and maintained, the color of the stamped concrete can fade as a result of direct exposure to sunlight, rain, and other weather conditions.
Sealing your concrete isn't really a labor-intensive, nor costly, job. By sealing your concrete every 2-5 years, as recommended by experts, you should keep your floor in good shape, preventing cracks, pitting, and additional damage.
Cons of Outdoor Concrete Staining
Transparent: The semi-transparency of most stains will fail to hide the existing imperfections in the concrete surface. DIY is not easy: Staining concrete is the not the easiest job for the amateur weekend warrior. Using a professional contractor ensure best results.
Low-maintenance: The same properties that make concrete floors so durable also make them easy to care for. Properly sealed concrete floors shrug off dirt, grit, stains, spills, and hard impacts. A little sweeping and damp mopping is all that's required to keep them looking like new.
Although concrete stain is permanent and won't flake off like paint, it penetrates only the top layer of the concrete surface and will eventually wear away as the surface is worn by traffic or weather exposure.
A clear sealer which turns frosty white in color has delaminated from the concrete surface. This is most likely due to the coating's inability to release water vapor trapped within the concrete quickly enough to prevent pressure buildup beneath the coating.
Water-based sealers do not change the color of the decorative concrete, but solvent-based sealers darken the color by several shades. This darkening effect is called color saturation. The color saturation remains as long as the seal coat is maintained.
Acid-stained concrete is easy to maintain and will last indefinitely. You just need to follow several basic principles: Dust mop or broom sweep weekly to prevent dirt accumulation. Damp mop monthly to remove smudging, scuffs and water marks, and to restore gloss.
Two coats are usually sufficient. Before resuming traffic on the surface, be sure the stain has dried for the manufacturer-recommended time. On exterior surfaces, you can apply a solvent-based, solid-color concrete sealer.
A hose or pressure washer can help remove mold, mildew or water stains from concrete patios and driveways. If staining persists, use a mold remover or bleach solution to treat the area. Then scrub the stain with a brush and rinse thoroughly with clean water.
Leaving concrete unsealed will leave it with a flat look. The color will remain flatter and dull, in addition to the concrete remaining porous and easier to damage. Sealing the concrete will enhance the colors and give it more of a marble or mottled look, smoother and with richer colors.
Wait at least 30 days before sealing a new concrete surface—whether indoors or out—so that it has time to completely cure first. For the best results, the concrete surface should be clean and dry.
Heavy coats of sealer, or a buildup of sealer applied numerous times over the years, will cause moisture to become entrapped under the sealer and, in time, the sealer loses adhesion from the concrete.