basement waterproofing paint

A Beginner’s Guide to Basement Waterproofing: How To Do It Right

A wet basement can be a homeowner’s nightmare, leading to costly repairs, mold growth, and even structural damage. In our years of remodeling basements in Minneapolis, we’ve seen moisture cause fortunes of damage to our customer’s basements. Fortunately, with the right knowledge and tools, you can waterproof your basement yourself! In this comprehensive guide on basement waterproofing how to, we’ll explore the causes of wet basements, the various DIY waterproofing methods, and how to choose the right solution for your specific needs. Let’s dive in!

Short Summary

  • Understand the causes of wet basements and identify sources, such as hydrostatic pressure & inadequate waterproofing.

  • Evaluate specific basement needs to tailor effective protection solutions.

  • Prevent water infiltration through regular inspections, maintenance of drainage systems, sealing openings and professional exterior/interior waterproofing services.

Understanding the Causes of Wet Basements

basement waterproofing for a wet basement

Before you can effectively waterproof your basement, it’s crucial to understand the root causes of wet basements. The main culprits are hydrostatic pressure, poor drainage systems, and inadequate waterproofing. By identifying the source of your basement’s moisture problems, you can ensure that your waterproofing efforts will be both efficient and long-lasting.

Hydrostatic pressure occurs when water accumulates around your foundation, exerting pressure that can lead to leaks and cracks. Inadequate drainage systems may result in water pooling around your foundation, increasing the risk of basement leaks. And finally, insufficient waterproofing can stem from improper installation or use of low-quality materials, allowing water infiltration.

Hydrostatic Pressure

Hydrostatic pressure can have a significant impact on your basement’s waterproofing, causing water infiltration through foundation cracks and even shifting the foundation itself, leading to structural damage. To prevent hydrostatic pressure from wreaking havoc on your basement, ensure proper drainage around your foundation, install a sump pump, and apply waterproofing materials to the foundation walls.

Regular inspections and prompt repairs are essential in maintaining a dry basement and avoiding further damage from hydrostatic pressure.

Poor Drainage Systems

Poor drainage systems can lead to a host of basement problems, including water damage, flooding, and mold growth. To improve your basement’s drainage, consider the following options:

  • Installing gutter extensions

  • Restoring the crown

  • Reshaping the landscape

  • Repairing footing drains

  • Installing a curtain drain

Additionally, waterproof coatings and sealants can be applied to concrete walls to achieve waterproofing.

Inadequate Waterproofing

Inadequate waterproofing can not only result in water infiltration, but also contribute to mold growth and structural damage. Common sources of basement wall leaks include window wells, which can be addressed by using waterproof coatings and sealants. When applying a waterproof sealer to basement walls, ensure that the area is clean, dry, and free of debris for optimal results.

Efflorescence, white deposits that form on the surface of masonry walls due to constant moisture, can be addressed using muriatic acid.

Evaluating Your Basement’s Waterproofing Needs

Before diving into waterproofing solutions, it’s essential to evaluate your basement’s specific waterproofing needs. This involves identifying water sources, assessing humidity levels, and inspecting walls and floors for signs of water infiltration.

By understanding your basement’s unique situation, you can tailor your waterproofing efforts to ensure lasting protection and avoid costly mistakes.

Identifying Water Sources

Identifying water sources in your basement is a crucial step in addressing moisture issues. Check for wet streaks, cracks, and other signs of moisture on your basement walls and floors. Common water sources in basements include surface water, groundwater, and rainwater. To address these water sources, consider installing a sump pump, a French drain, or waterproofing your basement walls and floors.

Preventing moisture in your basement can be achieved by maintaining gutters and downspouts, grading your yard away from your home, and inspecting your basement regularly for signs of moisture.

Assessing Basement Humidity Levels

Maintaining proper humidity levels in your basement is crucial in preventing mold growth and ensuring a comfortable living environment. Ideally, basement humidity levels should be between 30% and 50%. To measure your basement’s humidity levels, you can use a hygrometer or perform an aluminum foil test.

If your basement’s humidity levels are consistently high, consider using a portable room dehumidifier or a whole-house humidifier system to address the issue.

Inspecting Basement Walls and Floors

Regular inspections of your basement walls and floors are essential in identifying potential water infiltration and structural damage. Look for cracks, efflorescence, and other signs of water infiltration during your inspection.

Additionally, bi-annual foundation inspections can help you address potential maintenance issues before they escalate into costly repairs.

Interior Waterproofing Solutions

basement waterproofing interior

Interior waterproofing solutions can be an effective way to protect your basement from moisture and water infiltration. These basement waterproofing methods include waterproof coatings and sealants, installing an interior drainage system, and addressing window well leaks. By implementing these interior waterproofing techniques, you can create a dry and comfortable living space in your basement.

Applying waterproof coatings and sealants to your waterproof basement walls can prevent moisture from seeping through, avoiding a wet basement. Waterproofing basement walls techniques, such as an interior drainage system, can help direct water away from your foundation and prevent basement flooding.

And finally, addressing window well leaks by installing a drainage system and a sloped window well cover can prevent water from entering your basement through your windows.

Waterproof Coatings and Sealants

Waterproof coatings and sealants are an essential component of interior waterproofing. These coatings can be applied to interior walls to prevent moisture from seeping through, protecting your basement from water infiltration.

Silicate-based concrete sealers, for example, penetrate and react chemically with the components of the concrete or brick, forming a hard, waterproof surface. Make sure to choose high-quality waterproof coatings and sealants, such as hydraulic cement, as they can significantly impact the effectiveness of your basement waterproofing efforts.

Installing an Interior Drainage System

Installing an interior drainage system in your basement can help prevent basement flooding by directing water away from your foundation. Here’s how it works:

  1. A drainage channel is installed beneath the basement floor.

  2. The drainage channel collects water that enters the basement.

  3. The collected water is directed away from the foundation.

  4. A sump pump is used to pump the water away from the house.

By installing an interior drainage system, you can protect your basement from water damage and keep your foundation safe.

The estimated cost of installing an interior drainage system is approximately $5,000, but its benefits in protecting your basement from water damage make it a worthwhile investment.

Addressing Window Well Leaks

Window well leaks are a common source of water infiltration in basements. To address these leaks, you can install a drainage system in the window well and apply a sloped window well cover to disperse rainwater away from your basement.

In addition, sealing the window with a caulk suitable for use on masonry can help prevent water from entering your basement through your window well.

Exterior Waterproofing Solutions

waterproofing a basement from the exterior

Exterior waterproofing solutions can also play a significant role in keeping your basement dry and protected from water infiltration. These solutions include foundation excavation and waterproofing, grading and yard drainage, and gutter and downspout maintenance. By implementing these exterior waterproofing methods, you can further safeguard your basement from water damage and create a dry, comfortable living space.

Foundation excavation and waterproofing involve digging around your foundation and applying a waterproof coating or membrane to the exterior walls. Grading and yard drainage help direct water away from your foundation, reducing the risk of basement leaks. And finally, gutter and downspout maintenance can prevent water from pooling around your foundation and causing basement leaks.

Foundation Excavation and Waterproofing

Foundation excavation and waterproofing can be a costly but effective exterior waterproofing solution. By excavating around your foundation and applying a waterproof coating to the exterior walls, you can protect your basement from water infiltration and potential structural damage. Liquid applied membranes are typically used as the primary waterproofing layer for foundation walls.

Although the process can cost between $10,000 and $15,000, the long-term benefits in protecting your basement make it a worthwhile investment.

Grading and Yard Drainage

Proper grading and yard drainage are essential in preventing basement leaks. By landscaping your yard to direct water away from your foundation, you can avoid water accumulation near the foundation or along basement windows.

The recommended slope for yard drainage and grading is a minimum drop of two to three inches in every ten feet, with a maximum grade in a lawn not exceeding twelve inches for every four feet. Keep in mind that soil type, precipitation, and plant type should also be considered when assessing grading and yard drainage.

Gutter and Downspout Maintenance

Maintaining your gutters and downspouts is a simple yet effective way to prevent basement leaks. By cleaning your gutters and downspouts at least twice a year, and more frequently if there are numerous trees nearby, you can prevent water from pooling around your foundation.

Check for clogs in your downspouts and remove them, and inspect for signs of rust or damage, addressing these issues with a wire brush, rust-inhibiting primer, and paint. Regular gutter and downspout maintenance can go a long way in keeping your basement dry and protected from water infiltration.

Choosing the Right Basement Waterproofing Company

Although this guide focuses on DIY basement waterproofing, it’s essential to recognize when to call in the professionals. Choosing the right basement waterproofing company is crucial in ensuring that your basement remains dry and protected from water infiltration. To select the right company, consider their experience, reputation, and the quality of their materials and workmanship.

Ensure that the basement waterproofing company you choose is licensed, insured, and bonded, as this is a requirement for these professionals. The typical total cost of professional waterproofing ranges between $1,900 and $6,000; however, the investment in professional waterproofing services can save you from costly repairs and damage in the long run.

Preventative Measures for a Dry Basement

In addition to implementing the waterproofing methods discussed in this guide, it’s essential to take preventative measures to maintain a dry basement. Regular inspections, proper maintenance of drainage systems, and addressing any signs of water infiltration promptly can help prevent water damage, structural damage, and mold growth.

Improving outside drainage by installing gutters and downspouts, grading the soil around your foundation, and installing a sump pump can help prevent water from reaching your foundation. Sealing openings to your basement, such as caulking cracks in your foundation and sealing around windows and doors, can further protect your basement from moisture infiltration.

By taking these preventative measures, you can ensure a dry and comfortable basement for years to come.


In conclusion, basement waterproofing is a crucial task for any homeowner looking to prevent water damage, structural damage, and mold growth. By understanding the causes of wet basements, evaluating your basement’s waterproofing needs, and implementing both interior and exterior waterproofing solutions, you can protect your basement and create a comfortable living space. Remember to take preventative measures and seek professional help when necessary to ensure a dry and healthy basement for years to come.

Frequently Asked Questions

Can you waterproof basement DIY?

DIY waterproofing your basement can be a daunting task, and it should not be taken lightly. Depending on the extent of the damage, it may be more cost-effective to hire a professional who can identify all problem areas and ensure that everything is properly sealed.

Consider all options before attempting to waterproof your basement yourself.

How do I waterproof my basement from the inside?

For effective waterproofing of your basement from the inside, you should apply a masonry waterproofing product to the walls and then seal/coat the interior with a suitable masonry waterproof product. This will create a watertight barrier to prevent any water infiltration.

By following this simple process, you can effectively waterproof your basement from the inside.

Is it better to waterproof basement from inside or outside?

Based on the evidence presented, it is generally better to waterproof a basement from the outside rather than inside. Exterior waterproofing involves removing soil and installing a powerful sealant which ultimately provides the most effective protection from wet basements.

What are the main causes of wet basements?

Excessive water in the soil around a home is typically the leading cause of wet basements, resulting from hydrostatic pressure, poor drainage systems, and inadequate waterproofing.

These issues can cause water to seep into the basement, leading to mold, mildew, and other structural damage. To prevent this, homeowners should take steps to ensure their home is properly waterproofed and that their drainage systems are functioning properly.

How can I identify water sources in my basement?

Inspect the walls and floors for any visible signs of water, like wet streaks or cracks. Additionally, check for a musty smell or discoloration that can be indicators of long-term water damage.

By carefully inspecting these elements, you can determine where water may be entering your basement.