How To Apply Concrete Sealer (With A Roller or Pump Sprayer)
Concrete sealer is an important component of any project that uses concrete, providing protection and maintaining its appearance. While these compounds are sometimes integrated into the concrete at the time it is poured, most sealing products are applied afterward.
These sealers are designed to either penetrate the concrete or to form a layer of protection. Homeowners looking to provide the best concrete protection need to understand how to apply these products properly.
Preparing Concrete For A Sealer
A clean surface is critical in order to make sure that the product is able to penetrate the surface or for it to bond securely.
Step #1: Sweep Up Dirt and Debris
The first step you should take is to sweep up any loose debris sitting on the concrete. This step will help you to save time as you proceed with further preparation.
Step #2: Remove Paint, Grease and Stains
Next, you need to remove materials that can not be removed with a broom of shop vac. This will include grease, paints, and stains that may be present. The products that you will need to use will depend upon the type of material that you seek to clean up. Make sure to follow the manufacturer's instructions to provide the best cleaning and to save yourself some time here.
Step #3: Clean Surface With Water
Once these stains have been cleaned, I recommend that you clean the surface with water. This extra step will help to remove extra materials that are still present in the concrete pores or debris that may still be lodged into depressions on the concrete surface. Removing these stains completely is critical as their presence will prevent the sealer from bonding on the concrete surface or inhibit them from penetrating into the pores.
Use A Wet Mop or Pressure Washer
You can use a wet mop to clean the surface or use a pressure washer to remove the remaining stains and cleaning supplies that you have used to remove them. A shop vac can be employed to pick up any water that remains standing and will help to speed up the drying process. You should make sure that the concrete is completely dry before proceeding any further.
If you have paint on the concrete that you need to remove, you can read my guide on how to remove paint from concrete for more information.
Step #4: Make Repairs
Finally, you will want to repair any surface damage before the sealant is applied. Cracks should be filled with the proper materials and it is important to allow for adequate drying time to make sure that they are ready to receive treatment. A fan can help you to speed up this process and will also promote extra ventilation in the area.
Removing Old Concrete Sealer
Before you put down a concrete sealer it will be important to determine if a protective layer has been previously applied. Pre-existing sealers can prevent the new concrete sealer from adhering to the surface or stop it from penetrating into the concrete's pores.
Choose Which Type Of Product To Use
Removing an old sealer will require either chemical products or equipment that can mechanically strip it away. Mechanical removal will require additional tools and the process has a greater chance of damaging the concrete surface, especially if it was made into a decorative form. For these reasons, most homeowners doing a DIY job will use chemical strippers to remove the old concrete sealer.
Don’t Let The Area Dry-Out
Follow all instructions provided by the manufacturer and make sure to keep the product moist. Strippers that dry before they are finished breaking down the sealer may not remove it completely from the surface. Covering the treated area with a moist cotton sheet will help to keep the stripper active and prevent it from evaporating.
Clean Area With a Mop or Pressure Washer
After you have removed the sludge that forms during the breakdown process, it will be necessary to wash the surface with a mop or pressure washer. This helps to remove the remaining material still present on the concrete as well as any chemicals that are still present. Again, make sure that the concrete is completely dry before moving on, using a fan if necessary.
Selecting An Application Method: Pump Sprayer vs Roller
Before you begin to apply the concrete sealer, you’ll need to determine what method will be used to apply it. There are a variety of ways to apply sealers, including various absorbing materials or tools such as a straight-edge. Two of the best methods to use for application are with a pump sprayer or a roller.
Using a Pump Sprayer
Pump Sprayers Are Easy To Use
Pump-up, or low-pressure, sprayers are easy to use and will require less work on your part when it comes to applying the sealer to your concrete. Using a pump sprayer allows you to provide maximum coverage with the least amount of waste. It can also save you time, as you will be able to cover a larger area with the nozzle than can be treated by a pass with a roller.
Choose The Appropriate Nozzle
Sprayers vary in their design and pressure available. You’ll want to review the operating manual in order to determine the nozzle settings as well as the distance required between the tip and the concrete surface. Following these instructions will allow you to apply the sealer evenly while making sure that it covers an area completely.
Use A Sprayer Made For Applying Chemicals
Make sure that the sprayer you plan to use will be not be damaged by the type of concrete sealer you plan to use. If the product is solvent-based, you need to make sure that the gaskets and hose are rated to handle the chemicals used. Fortunately, most sprayers can handle water-based sealants without any issue at all.
Using A Roller
Rollers Are Budget Friendly
A roller application will often be more budget-friendly than projects that require you to rent or purchase a sprayer. While a roller will require more time and energy, they can provide you with an even layer of sealant. Rollers are capable of applying either chemical-based or water-based products, but some rollers use materials that are better suited for the solvents used in chemical products.
Roller Length And Nap Size
While shorter rollers give you the best control during use, try to use a roller that is at least six inches in length. This will allow you to maintain even pressure while covering the concrete with fewer passes. Your sealant will dry evenly and quickly this way. You should also look for rollers that have a nap of between 3/8 and 1/4-inch so that they will hold enough product and will be able to penetrate the concrete pores.
My Favorite Concrete Sealers
Applying The Sealer
Various products have different characteristics when it comes to coverage and drying times. Follow the instructions provided in order to achieve the best results. Keep in mind that water-based products may require more coats than some solvent-based sealers, but they will often have shorter drying times.
Apply Sealant Coats Evenly
No matter what application method you use, it’s important to apply coats evenly. You should also apply a thin coating in a parallel pattern. Thin coats dry quicker and will offer you a consistent look. Working in the same direction as you make passes will also keep the product evenly placed and help to eliminate build-up or missed areas on uneven surfaces.
Apply At Least Two Coats
Keep in mind that concrete has pores, even on smooth finishes. You want to make at least two applications, possibly more depending upon the product that you use. It’s also important you allow for proper drying time between coats so that the layers bond properly.
Pro Tip: Using a fan will speed up this process and can add to ventilation.
Drying Time vs Curing Time
Think of dry time as the period needed for the surface of the sealer to dry, while cure time indicates the period needed for the sealer to dry completely through. Drying time will often be listed for hours, while curing time may require days.
Wait Between Coats (Dry Time)
Drying time will be provided by the manufacturer. More than likely, you will want to wait at least two hours between coats in order to create a strong barrier or allow for maximum penetration of the concrete surface.
Wait For Sealant To Cure Before Using (Curing Time)
Curing time should also be listed on the product's label. This is the amount of time needed before the concrete sealer is completely set. A fully cured surface can be walked on or driven on in the case of driveways or a garage floor.