How To Seal Concrete Floor From Moisture: DIY 10 Steps [Total]

Last Updated on January 20, 2023

When it comes to protecting your concrete floors from moisture, sealing is essential. Sealing your concrete floor can help keep it looking new and prevent water damage from occurring. It’s important to choose the right type of sealer for your needs and use it correctly in order to get the best results.

To do this, you need to thoroughly stir or shake the sealer, test out different brushes or rollers for even application, start at one corner of the room and make sure to get full coverage, apply more than one coat if needed and let each coat dry before applying the next. Finally, make sure to do a final check over once all coats are applied. 

How To Seal Concrete Floor From Moisture: DIY Steps

How do I stop moisture from coming through the concrete floor

To stop moisture from coming through a concrete floor, you’ll need to seal the concrete with a waterproofing sealer. This will create a barrier that locks out water and prevents it from entering the concrete and affecting the integrity of the structural components. The sealer should also contain an additive that provides extra protection against moisture intrusion.

Before applying the sealer, you’ll want to prep the surface of the concrete by cleaning it to remove any dirt or debris. Once this is done, you can apply a primer which will help create a bond between the substrate and sealer. Then, either brush or roll on your chosen waterproofing product in accordance with manufacturer instructions. 

Necessity of moisture-proofing concrete floors

Moisture-proofing concrete floors is necessary in order to protect them from water damage that can cause cracking and erosion over time. In addition, harsh weather conditions such as snow, rain, or high humidity can also contribute to deterioration if not properly sealed.

Sealing with a waterproof sealant helps create a protective layer around the floor that prevents moisture from seeping into cracks or crevices where it can cause long-term damage. 


Before beginning any work on the floor, it is important to properly prepare it for sealing. This includes thoroughly cleaning all dirt, grease, grime, oil, and other contaminants that could interfere with adhesion of the sealant later on. 

Cleaning the Concrete Surface 

The first step in preparation should be cleaning the entire surface of any dirt or debris using either a broom or vacuum cleaner depending on how much material needs to be removed. Make sure all fine particles have been cleared away so they won’t interfere with adhesion later on. 

Sweeping The Floor

Once larger pieces have been removed with either a broom or vacuum cleaner it’s important to use an actual broom for sweeping up finer particles like dust and dirt which can remain even after initial cleaning efforts are complete.

Be sure to use one with soft bristles so as not to scratch or otherwise damage the surface before applying any sealant materials.  

Scraping Off Any Oil Grease And Other Contaminants

After sweeping up fine particles any remaining oil grease and other contaminants should be scraped off manually using either a plastic scraper tool or putty knife being careful not to scratch or otherwise harm the surface during this process either.

Doing this will help ensure strong adhesion once you begin applying your chosen sealant material later on during this project .  

Using A Degreaser To Further Clean The Surface

If you find that further cleaning is needed after manual scraping then use an appropriate degreaser solution such as TSP (trisodium phosphate) diluted in warm water according to manufacturer guidelines . This solution should be applied directly onto any greasy spots left behind then scrubbed into those areas with either a stiff brush or coarse cloth such as burlap . Once done allow enough time for these areas to dry completely before proceeding any further .  

Washing The Floor

To ensure maximum cleanliness prior to applying your chosen sealant wash down all surfaces using plain water preferably using something like an outdoor power washer but at least using some sort of garden sprayer nozzle attachment connected directly onto your hose . Make sure you get all surfaces evenly wet before allowing time for everything including nooks and crannies too dry completely prior going onto next step in preparing your floor for sealing .  

Letting The Surface Dry Completely

It’s very crucial let each area dry thoroughly before attempting apply any kind adhesive backing material otherwise risk having weak bond between these two components resulting greater chance having problem down line somewhere along way when dealing something has do moisture prevention.

Allow plenty time drying process occur naturally without assistance artificial means such fan air heater etcetera allowing every last bit contained within wet area due course eventually fully dry out its own therefore no worry about consequences detrimental effects happening future doing certain things hurry rather than waiting patiently allowing nature take care itself during this phase construction project .

Checking for Cracks in the Concrete Surface

Checking for Cracks in the Concrete Surface

Assessing whether any small cracks are present

Once the surface has been cleaned, it is important to check if there are any minor cracks on the concrete surface. These cracks can be caused by weathering or just general wear and tear over time. It is important to identify these cracks as they can cause water seepage, weakening the sealer’s effectiveness.

To assess these small cracks, a flashlight or other bright light should be used to inspect all areas of the floor for hairline cracks and other imperfections. If any crack is found, it should be filled with an appropriate filler such as epoxy before applying a sealer. 

Filling In Any Large Cracks With An Appropriate Product

Before filling any large cracks with an appropriate product, it is important to make sure that all dust and debris are removed from within them. Using a vacuum cleaner or air compressor with a brush attachment can help keep large voids free of dust particles before filling them in with an appropriate product.

Once all debris has been removed, apply a concrete patching compound into the crack using a trowel or putty knife. Allow this compound to dry overnight before moving on to sealer application. 

Priming The Concrete Surface Before Applying Sealer

Priming is an important part of prepping concrete surfaces for sealers because it increases adhesion between both surfaces and creates strong protection against water penetration. Before applying primer onto the surface, make sure that all dust and dirt particles have been removed by vacuuming or sweeping it up with a broom or wet mop using detergent solution specifically designed for cleaning concrete surfaces.

Once clean, use a roller brush specifically designed for concrete surfaces to apply bonding primer in thin coats over the entire area allowing enough time between coats to dry properly (roughly 15 minutes). Once dry, move on towards sealer application following manufacturer’s instructions carefully depending on type used (water based versus solvent based).  

Sealing Process

Sealing concrete floors from moisture is a common job for many contractors and individuals. It can be an intimidating task that requires the right tools, supplies, and knowledge to get the job done correctly. If you’re looking to seal your concrete floor yourself, it’s important to understand each step of the process, so you can create a strong barrier against moisture that will last for years to come.

In this article, we’ll discuss how to properly choose an appropriate type of sealer based on your needs, apply it correctly, use different brushes or rollers for even application, start at one corner of the room, make sure to get full coverage, apply more than one coat if needed, let each coat dry completely and do a final check over once all coats are applied. 

Choosing an Appropriate Type of Sealer Based on Your Needs

When selecting a sealer for your concrete flooring project it is important to determine what type of protection you require and what type of finish you would like it to have. A water-based sealer will provide better protection against water penetration but may give off fumes during applications that may require additional ventilation.

An oil-based sealer will provide excellent resistance to oil stains but can be harder to clean up if spills occur during application. There are also specialized products designed for specific uses such as grease repellent or anti-slip properties that should be considered when selecting the appropriate type of sealer for your project. 

Applying the Sealer Correctly

Once the appropriate type of sealer has been chosen for your project there are several steps involved in applying it correctly: 

1. Stirring or shaking it thoroughly: 

Make sure that the sealant is mixed according to instructions before application by stirring or shaking it thoroughly in order to ensure an even distribution and proper adhesion when applied.  

2. Testing out different types of brushes or rollers:

Different types of brushes or rollers can be used depending on the desired look and feel of your floor surface after sealing. Brushes work best on smaller floors while rollers work better on larger surfaces but both must be tested prior in order to achieve even coverage without leaving any streaks or blotches behind. 

3. Starting at one corner of the room:

When applying the sealant begin at one corner and work outward in a crisscross pattern until all areas have been covered evenly without missing any spots. This will help ensure consistent coverage across the entire floor surface with no gaps left exposed.  

4. Making sure to get full coverage:

Take special care around corners and edges as well as high traffic areas such as hallways and entryways where foot traffic often occurs which may require additional coats for adequate protection from wear and tear over time.  

5. Applying more than one coat if needed:

Depending on how much protection is desired multiple coats may be necessary in order for full coverage which should always be allowed ample drying time between applications so that each layer adheres properly with no runs in between them once complete.

6 . Letting each coat dry completely:

Once all layers have been applied allow adequate drying time before walking on them or replacing furniture back into place so that they don’t stick together which could cause staining or discoloration over time due to trapped moisture beneath them when disturbed later down.

7 Doing a final check over once all coats are applied: 

Lastly conduct a thorough inspection once finished making sure there are no missed spots where water could seep through unchecked upon completion.

Definition of Concrete Floor Sealing

Concrete floor sealing involves applying a waterproof sealant to a concrete surface in order to protect it from water damage. This type of sealing helps prevent moisture from seeping into the concrete and causing cracking, erosion, or other destructive effects.

It also helps make cleaning easier by creating a barrier that prevents dirt and debris from collecting in the concrete. Sealants generally come in two forms clear acrylics for general protection or elastomeric coatings for extreme protection against water damage. 

Why is my concrete floor always wet?

There can be many causes for why your concrete floor may be wet – some of these include groundwater seeping into your basement, condensation due to high humidity levels in your home or maybe even high indoor temperatures causing sweating of pipes underneath your floor slab.

In order to determine what is causing the moisture on your concrete floor, it’s best to carry out some tests such as using a moisture meter which measures how much moisture is present in each section of your basement floor. This can help identify where exactly the problem lies so that you can take steps to address it directly. 

Does Really concrete sealer stop moisture?

Concrete sealers are designed to protect against penetration of water vapor into concrete substrates and help keep excessive amounts of moisture outside surfaces and away from structural materials like wood framing or steel reinforcing bars. Waterproofing sealers provide an added layer of protection against unwanted elements when applied correctly and correctly maintained over time.

While there are various types available on the market, they generally work by creating an impermeable barrier between inside and outside surfaces, preventing water from entering and damaging underlying structures beneath them. 

Can you seal a wet basement floor?

Sealing a wet basement floor is possible depending on how saturated it is with water – if there’s too much standing water then you won’t be able to effectively apply most sealers as they’ll simply run off without adhering properly if applied too thinly.

However, if there’s only a small amount of excess moisture present then you can usually proceed with sealing after proper preparation has been done – this includes cleaning off any dirt and debris from the surface using degreasers before using a dehumidifier to dry things out completely up until all liquid has evaporated away at least 24 hours prior to application (or longer if needed).

You can then choose a proper solvent-based epoxy or polyurethane sealant (following manufacturer instructions) which will help form an effective waterproof layer over your basement floor while also providing additional protection against chemicals leaking into or through the existing foundation material beneath it.


In conclusion, properly sealing your concrete floor can help make it last longer while protecting it from water damage. To ensure this is done effectively, be sure to choose an appropriate type of sealer based on your needs; stirring or shaking it thoroughly; testing out different types of brushes or rollers for even application.

Starting at one corner of the room and making sure to get full coverage; applying more than one coat if needed; letting each coat dry completely; and doing a final check over once all coats are applied. With these steps in mind, you can be confident that you’ll have sealed your concrete floor properly so that it stays protected from moisture for years to come!

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