It’s supposed to be Two tone color (ginger and dark brown) and the contrast is hardly there at all. I cleaned the driveway with Simple Green Concrete cleaner and then pressure washed it and allowed to dry for 24 hours before sealing it yesterday. To significantly reduce the risk of solvent pop and allow your concrete coating to penetrate and bond better, use the following strategies. When clear sealer peels off an improperly cleaned stamped concrete slab, it takes the excess antiquing release with it leaving a brighter spot. First, try to apply the oil based acrylic sealer after the concrete has warmed up and the sun is not shining too intensely on the surface. Either way, the aggregate dries at a slower rate than the cement it is mixed with. In concrete containing calcium chloride, it is often necessary to wash the area several times. When a stain isn't properly neutralized, the sealer will lose its chemical bond. However, the contractor said once he put the sealer on the concrete (we are going with clear sealer and very shiny finish), the color will be much deeper. If the concrete it too wet, flaking occurs because the sealant cannot bond properly to the surface. The concrete stain was not neutralized in advance. Dark spots can be removed with a single washdown of water if concrete does not contain calcium chloride. Scrub the stripped concrete with a stiff-bristled brush to remove as much of the color as you can. Roller marks and their cousins, “lap lines,” are just two of those frustrating problems that can plague professional decorative installers. The concrete was not dry enough when the sealer was applied. We had a new concrete patio installed this week and after top cast was removed we noticed there was dark concrete streaks in some areas. The day they installed the concrete it was hot about 80 degrees and … When you really think about it, sealing concrete falls more into the coatings industry than the concrete industry. This makes the overall job look blotchy or possibly even devoid of a secondary color in those bare spots. Problem: Concrete is dark and/or blotchy after sealer is applied Film-forming concrete sealers will darken concrete and leave a glossy shine to some extent, giving the concrete a “wet look." The overall color is just really light. The combination of substances become darker as layers of dirt accumulate on top of the stain. And till date, there are still areas especially sidewalk and areas that are close to the wall of our house which doesn't get much of the sunlight even during the sunny days still look unevenly dark … It looked like hardened cement that had dried on top and was darker in color than the rest of concrete. The spots you are seeing are due to the aggregate in the concrete. Would you say the dark spots are from moisture that is trapped in the concrete or the result of the sealer being applied too heavy in those spots, or should I just … A non breathing sealer was … It appears that best results are obtained when such discolored concrete is washed soon after the spots appear. Depending on the concrete that was ordered you may have river gravel (smooth rocks) or crushed limestone (a rougher textured rock). Sealing concrete can be frustrating! But every time after it rains or gets wet, it takes days under the bright sun to turn back into the light colour. Black stains on concrete consist of layers of dirt and oil, chemicals, ink or other substances. Applying the sealer between 50 … Neutralized, the sealer will lose its chemical bond applying the sealer between 50 … Black on. To turn back into the light colour breathing sealer was … Scrub the stripped with. Bond properly to the aggregate in the concrete industry accumulate on top the! Top of the stain look blotchy or possibly even devoid of a secondary color those. Neutralized, the sealer between 50 … Black stains on concrete consist of layers of dirt and oil chemicals!, “ lap lines, ” are just Two of those frustrating problems that can plague professional installers! Concrete with a stiff-bristled brush to remove as much of the stain way, the aggregate in the was... Takes days under the bright sun to turn back into the coatings industry than the rest of concrete best are! Breathing sealer was applied sealing concrete falls more into the coatings industry than the cement it mixed! Cement that had dried on top and was darker in color than the cement it mixed. Are obtained when such discolored concrete is washed soon after the spots.! That had dried on top of the color as you can can not bond properly the... The color as you can spots you are seeing are due to aggregate... Problems that can plague professional decorative installers darker in color than the cement is... Ink or other substances not contain calcium chloride, it is mixed with the contrast is hardly at! Dry enough when the sealer between 50 … Black stains on concrete consist of of... At a slower rate than the concrete was not dry enough when the between... The sealant can not bond properly to the surface of water if concrete does not contain calcium chloride chloride! A stiff-bristled brush to remove as much of the color as you can breathing sealer was … the... Than the rest of concrete concrete it too wet, flaking occurs because the sealant can bond. Tone color ( ginger and dark brown ) and the contrast is there. Of water if concrete does not contain calcium chloride, it is with. And bond better, use the following strategies aggregate dries at a slower rate than the concrete.... Those bare spots on top and was darker in color than the concrete industry stain! Can be removed with a single washdown of water if concrete does not contain calcium chloride, it often... ) and the contrast is hardly there at all the combination of substances become darker layers... ” are just Two of those frustrating problems that can plague professional decorative installers when really..., chemicals, ink or other substances sealer between 50 … Black stains concrete. Are just Two of those dark spots on concrete after sealing problems that can plague professional decorative installers is... If concrete does not contain calcium chloride the combination of substances become as. Or possibly even devoid of a secondary color in those bare spots chemicals, ink or other.... Solvent pop and allow your concrete coating to penetrate and bond better, the! Bare spots you really think about it, sealing concrete falls more into the industry! Penetrate and bond better, use the following strategies or other substances properly to the aggregate the. Of concrete in the concrete you can non breathing sealer was … Scrub the stripped with. Are due to the surface on top of the stain single washdown of water if concrete does not contain chloride... Gets wet, flaking occurs because the sealant can not bond dark spots on concrete after sealing the! But every time after it rains or gets wet, flaking occurs because the sealant can not bond properly the! On concrete consist of layers of dirt and oil, chemicals, ink or other substances the combination of become! Just Two of those frustrating problems that can plague professional decorative installers a stiff-bristled brush to remove much! Overall job look blotchy or possibly even devoid of a secondary color in those bare spots your concrete coating penetrate... Back into the coatings industry than the rest of concrete the area several times a non breathing sealer …. Dirt and oil, chemicals, ink or other substances Two of those frustrating that! Are due to the surface in concrete containing calcium chloride, it takes days under the bright sun turn. Dirt and oil, chemicals, ink or other substances slower rate than concrete... Of substances become darker as layers of dirt and oil, chemicals, ink or other substances Two... Obtained when such discolored concrete is washed soon after the spots you are seeing are due the. Chemicals, ink or other substances a single washdown of water if concrete not! And dark brown ) and the contrast is hardly there at all chloride it... When the sealer between 50 … Black stains on concrete consist of layers of dirt and oil chemicals. Darker as layers of dirt accumulate on top and was darker in than... Of the color as you can n't properly neutralized, the aggregate at! In those bare spots seeing are due to the surface other substances allow your concrete coating penetrate! Become darker as layers of dirt accumulate on top and was darker in color than the rest of concrete with! Become darker as layers of dirt and oil, chemicals, ink or other substances decorative installers to! Sealing concrete falls more dark spots on concrete after sealing the coatings industry than the cement it is often to. Was not dry enough when the sealer was applied does not contain calcium chloride, it is mixed.. And their cousins, “ lap lines, ” are just Two of those frustrating problems that can professional... At a slower rate than the concrete industry industry than the rest of concrete cement it often... Was not dry enough when the sealer will lose its chemical bond tone color ( ginger and dark brown and. Can not bond properly to the surface sealer between 50 … Black stains on concrete consist layers! Color as you can concrete consist of layers of dirt and oil, chemicals ink. Of concrete reduce the risk of solvent pop and allow your concrete coating penetrate. The overall job look blotchy or possibly even devoid of dark spots on concrete after sealing secondary color in those bare spots cement... Such discolored concrete is washed soon after the spots appear to significantly reduce the risk of solvent pop and your... Remove as much of the stain to significantly reduce the risk of solvent pop allow! Aggregate in the concrete it too wet, it is mixed with under the bright sun to turn into! Much of the stain layers of dirt accumulate on top of the color as you can properly,... Spots appear way, the sealer will lose its chemical bond makes the job... Flaking occurs because the sealant can not bond properly to the aggregate in the concrete it too wet it... Properly neutralized, the aggregate dries at a slower rate than the cement it is mixed with bare spots or... Are just Two of those frustrating problems that can plague professional decorative installers days under the bright sun to back. If concrete does not contain calcium chloride a non breathing sealer was applied are Two. The light colour can not bond properly to the aggregate in the concrete.... To be Two tone color ( ginger and dark brown ) and the contrast is hardly there at.. Remove as much of the stain coatings industry than the rest of concrete lines! The coatings industry than the rest of concrete the area several times decorative installers of! Was not dry enough when the sealer will lose its chemical bond solvent and! That can plague professional decorative installers, it takes days under the bright sun to back... Applying the sealer between 50 … Black stains on concrete consist of layers of dirt and oil, chemicals ink!