If you don't seal a concrete floor, it becomes highly porous, leading to permanent stains from spills (oil, grease), moisture damage (mold, mildew, freeze-thaw cracking), dusting (surface breakdown into powder), and premature wear, significantly reducing its lifespan and curb appeal, while increasing maintenance needs. Unsealed concrete acts like a sponge, absorbing contaminants and weakening structurally over time.
If concrete is left unsealed, a number of issues can occur over time: Surface staining from oil, grease, dirt, or rust. Moisture damage including cracking, spalling, and weakening. Mould and mildew growth, especially in damp or shaded areas.
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.
Increase the durability of your floors by having them properly sealed. A sealed concrete floor will be protected from the elements, preventing cracking, scaling, and other common concrete problems. Sealing your concrete floors prevents damage – no matter how regularly your floors are used.
Don't do it... Here's why... unsealed concrete is porous. It will help wick water away, for example coming in from a rainy day. Once you seal it the water will just stand there and collect dirt and you will track it in your house. Once you seal it there is NO going back.
Concrete sealers have disadvantages like creating slippery surfaces, requiring frequent reapplication (maintenance cost), potentially discoloring or staining, trapping moisture (causing blisters), and using harsh chemicals (VOCs), with application issues like bubbling arising from poor preparation or wrong product choice. While offering protection, the cost, labor, and upkeep for maintaining the desired look can be significant drawbacks for homeowners.
The 10-20-30-40 concrete rule is a rule of thumb for mix proportions by volume: roughly 10% cement, 20% water & air, 30% sand, and 40% gravel/stone, aiming to use as much cost-effective aggregate as possible while the cement paste binds it. This ratio creates a strong, well-graded mix where smaller particles fill gaps in larger ones, reducing void space and cement needs, making it economical and durable for general construction.
Common Signs It's Time to Reseal Your Concrete Floor (Driveway, Basement, Patio)
Concrete is incredibly durable, but if it isn't sealed properly, it can chip or show wear in certain situations. A quality, professionally installed sealant reduces wear and tear, thereby extending the life of your concrete driveway.
Yes, you can skim concrete over existing concrete for resurfacing, often using a thin concrete overlay or microcement, but success depends heavily on proper surface prep: thoroughly clean the old concrete, repair cracks, and apply a strong bonding agent to ensure the new layer adheres well and lasts, preventing issues like peeling or cracking. Skim coating, also called micro-topping, provides a new, updated look for floors, patios, and even vertical surfaces.
Late winter, early spring, and fall offer the most suitable conditions for sealing concrete in the Southeast, with temperatures ranging from 50° F to 80° F (10° C to 27° C). Sealing your concrete during this time allows for proper curing and maximum protection.
Unsealed concrete can generate dust particles that may irritate respiratory systems. However, properly sealed and polished concrete eliminates this concern and can actually improve indoor air quality compared to carpet and other traditional flooring materials.
Applying a high-quality concrete sealer can protect the surface from moisture, freeze-thaw cycles, and environmental damage. Sealing helps prevent the concrete from absorbing water, which is a common cause of cracks in cold weather when water freezes and expands within the concrete.
Unsealed concrete faces a high risk of staining from liquids and chemicals. Its porous nature allows substances like oil, grease, and harsh solvents to seep deep into the surface. This penetration causes permanent discoloration and weakens the material over time.
Concrete floors should be finished just like the walls in your house. We don't leave just the drywall. We prime and paint to protect them and make them look good.
Basic cleaning: Use a broom, dustpan, mop, buckets, warm water, and mild detergent (such as dish soap or Castile soap). Specialized cleaning: Super Blue Concentrated: for tough stains or deep cleaning (only for unsealed or uncoated concrete)
A properly sealed floor can reduce water vapor transmission, protect against staining, and extend the lifespan of both the concrete and any flooring materials above it.
Longevity: With proper maintenance, polyurethane sealers can last 5-10 years or more. Aesthetic Options: They come in various finishes, including high-gloss and satin.
Cost of Sealing Concrete Per Square Foot
Its average price ranges from $0.20 to $0.60 per square foot , excluding labor. However, with labor expenses, concrete sealing costs $2 and $3 per square foot . In the table below, we consider the multiple sizes of floor and their concrete sealing rate according to 2023 data.
The "90-minute concrete rule" was a standard guideline (ASTM C94) requiring ready-mix concrete to be discharged from the truck within 90 minutes (1.5 hours) of mixing to ensure workability and quality, but this rule has been updated, allowing for custom time limits to be set by the purchaser and producer, acknowledging modern admixtures that extend working time, though the original principle of limiting time to maintain quality remains crucial.
Generally, a driveway needs to be resealed every 2 to 10 years. The amount of time ranges so greatly because the frequency depends on a few things: How your driveway is used.
Testing for 7-days helps to identify potential issues with the concrete mix or curing process early in the construction phase, allowing for timely corrective measures. If the 7-day strength is significantly below 65%, It might indicate problems with the concrete mix, curing, or other factors that need to be addressed.
The process should take about 15 minutes, which is the longest time needed for 30 SECONDS Outdoor Cleaner. Ironic, we know. But brick and concrete are porous and rough. On the bright side, 30 SECONDS is safe for lawns and landscaping and provides great results!
Understanding Grades of Concrete
The grade of concrete is understood in measurements of MPa, where M stands for mix and the MPa denotes the overall strength.
Dry Volumn Concrete = Approximate 54 % to 57 % more than Wet Volumn Concrete. so, considering the factor of safety ranging from 1.54 to 1.57 to counter that shrinkage. i.e., Volume of dry concrete = 1.54 to 1.57 times Volume of wet concrete.