Dealing with a flooded basement is a challenging and costly experience. Waterproofing your basement is a proactive solution to avoid flood damage, mould growth, and structural problems caused by excess moisture.
When it comes to basement waterproofing, homeowners often wonder whether it’s best to waterproof from the inside or the outside. This guide will help you understand the options available, the pros and cons of each, and how to make the best choice for your home.
Let’s get straight to the point.
Waterproofing your basement can be done inside or outside, depending on your water issues. Interior waterproofing is more affordable and quicker, addressing water that enters the basement through cracks or leaks.
It involves installing drainage systems like sump pumps and sealants to manage water. Exterior waterproofing stops water before it reaches your foundation, using membranes and drainage tiles, but it is more costly and labour-intensive.
Exterior solutions are better for frequent flooding or pooling, while interior fixes can manage minor leaks. Combining both methods provides the most protection.
Interior Basement Waterproofing
Waterproofing the inside of your basement is one of the most effective ways to protect your home from water damage. This method seals the basement from the inside, preventing water from entering the living space.
How Interior Waterproofing Works?
- Trenching and Drainage System: The first step is to dig a trench around the perimeter of the basement floor. A sump pump is usually installed inside this trench to divert water that accumulates below the foundation, preventing it from seeping into the basement. The trench is then sealed with concrete.
- Concrete Sump Pumps: Installing a sump pump is important for managing potential floodwater. In a flood, the sump pump can efficiently remove large volumes of water, safeguarding your home from severe damage.
- Sealants and Coatings: Interior waterproofing may involve applying concrete sealants or coatings to the walls and floors. These products help block moisture from entering the basement.
- Dehumidifiers: Dehumidifiers can be a valuable addition to your basement in humid climates. It can lower humidity levels by as much as 50%, reducing the risk of mould growth and improving air quality.
Advantages Of Interior Waterproofing
- Cost-Effective: Interior waterproofing is generally more affordable than exterior waterproofing. Sealing interior cracks might cost a few hundred dollars, while exterior work can run into the thousands.
- No Weather Limitations: Unlike exterior methods, interior waterproofing can be done at any time of year. There’s no need to wait for dry weather or deal with frozen ground.
- Quick Installation: Installing an interior system is typically faster because it doesn’t involve digging around the foundation, which requires extensive labour and time.
- Long-Lasting Solutions: Interior waterproofing methods offer long-term protection, such as injecting polymers into foundation cracks. These materials can expand and contract with temperature changes, reducing the likelihood of future leaks.
Disadvantages Of Interior Waterproofing
- Doesn’t Address External Sources: While interior waterproofing effectively manages water that enters the basement, it doesn’t stop the water from reaching your foundation in the first place.
- Limited to Managing Symptoms: This method handles the water that enters but doesn’t address the underlying issues outside the house that may be causing water to pool near the foundation.
Exterior Basement Waterproofing
Exterior basement waterproofing focuses on stopping water before it reaches your foundation. This method is more comprehensive but requires more effort and expense.
How Exterior Waterproofing Works?
- Water Redirection: The first step is to direct water away from the house before waterproofing the foundation. Gutters, downspouts, and proper grading around the house ensure water flows away from the foundation.
- Membranes and Drainage Tiles: A waterproof membrane is applied to the foundation walls, creating a barrier between the soil and the structure. Drainage tiles or pipes are installed along the foundation’s base to channel water away from the home.
- Grading and Slope Adjustments: Ensuring the ground slopes away from the foundation prevents water from pooling near the house. You may need to regrade the landscape or install additional drainage to keep the water at bay.
Advantages Of Exterior Waterproofing
- Stops Water Before It Reaches the Basement: Exterior waterproofing’s main benefit is preventing water from contacting your basement walls. This reduces the risk of long-term structural damage to the foundation.
- Prevents Mould and Mildew: Exterior waterproofing helps prevent mould, mildew, and condensation inside the basement by keeping water away from the foundation.
- Ideal for Severe Water Issues: If your home has persistent water problems, such as significant flooding or pooling water near the foundation, exterior waterproofing is the most effective solution.
Disadvantages Of Exterior Waterproofing
- Costly and Labour-Intensive: Excavating around the foundation, installing drainage systems, and repairing landscaping afterwards can be expensive. It’s also a more labour-intensive process than interior waterproofing.
- Weather-Dependent: Exterior waterproofing requires dry conditions, which can delay the project. Frozen or overly wet ground can complicate the excavation process.
- Damage to Landscaping: The excavation required for exterior waterproofing can damage your landscaping, fencing, driveways, and decks. Once the waterproofing is complete, additional time and expense may be needed to restore these features.
When To Choose Interior Waterproofing?
Interior waterproofing is generally the best option when:
- Water Enters Occasionally: If you only notice water during heavy rain or snowmelt, interior waterproofing can handle these occasional leaks effectively.
- You Have a Finished Basement: If you’ve already invested in finishing your basement, interior waterproofing protects your investment without requiring major structural work.
- Foundation Cracks Are Visible Inside: If cracks or leaks are visible inside the basement walls, sealing these from the inside can solve the problem without the need for costly excavation.
When To Choose Exterior Waterproofing?
Exterior waterproofing is recommended when:
- You Notice Frequent Flooding or Pooling Water: If water regularly pools near your foundation or you experience significant flooding, exterior waterproofing will address the root cause of the problem.
- Basement Walls Show Signs of Water Damage: Discoloured walls, mould, and condensation indicate water penetrating your basement outside. Exterior waterproofing is essential in these cases to prevent structural damage.
- You Plan to Build or Renovate: If you’re building a new home or planning a major renovation, installing exterior waterproofing during construction is the best way to protect your foundation from future water damage.
Signs You Need To Waterproof Your Basement
If you’re unsure whether you need basement waterproofing, watch for these warning signs:
- Water Puddles: Any water pooling on your basement floor indicates a problem.
- Discoloured Walls and Floors: Water damage can appear as stains or discolouration on walls or floors.
- Condensation on Windows: Excess moisture can cause basement windows to fog up.
- Mould or Mildew: Mould or mildew suggests moisture is present and should be addressed immediately.
- Musty Odours: A persistent damp smell in the basement often indicates water seepage.
- Cracked or Warped Doors: Swollen or warped doors can result from high humidity levels in the basement.
Conclusion
Whether you waterproof your basement from the inside or outside depends on your situation, if water enters occasionally and the issue is relatively minor, interior waterproofing is a quicker, more affordable solution.
However, if you experience frequent flooding or significant water damage, exterior waterproofing is essential to prevent future problems. In some cases, combining both methods may be the best way to protect your home fully.
Regardless of your chosen method, working with a reputable waterproofing professional ensures the job is done correctly, protecting your home and investment for years.
FAQs About Waterproofing Basement
What Can Be Used To Waterproof Basement?
A masonry waterproofing product should be applied to the bare interior basement walls. If your foil test showed that water is soaking through your basement walls and leaving them wet, seal the interior of the walls with a high-quality waterproof paint.
How Do You Waterproof A Concrete Basement Floor?
Two of the best options for waterproof basement flooring are epoxy paint and sealed concrete. Both are affordable and durable and allow for adequate waterproofing. Epoxy paint dries thick and hard, providing the necessary durability for maintaining a basement floor.
Is Rubber Flooring Good For Basements?
Additionally, rubber is one of the best floors for basements that flood. It’s water-resistant and easy to clean and replace. Features of Rubber Flooring for Basements: Durable and shock-absorbing, it is Perfect basement flooring for home gyms.
Should I Waterproof My Basement From The Inside Or Outside?
Though labour-intensive and expensive, waterproofing your basement from the outside is the most efficient way of preventing water and moisture build-up around the house’s foundation.
Can You Use Flex Seal To Waterproof A Basement?
Flex Seal Liquid is thicker than paint and dries into a strong, rubberised coating. It can also help seal out air, water, and moisture and is chemical—and mildew–resistant, making it a great choice for your basement walls. Start by taping off the walls; you will waterproof them with blue painter’s tape.
