Is it Better to Waterproof a Basement from the Inside or Outside?

A basement is much more than extra square footage for New Jersey homeowners — it is a vital part of their foundation and home. But a basement can quickly be ruined by water finding its way inside. Basement water can lead to mold, pest infestation, and even foundation wall damage.

Water has a funny habit of finding its way into basements. According to research from the insurance industry, 98% of homes in the U.S. will experience basement water damage. Places like New Jersey, which have high levels of humidity and clay content in the soil, are more susceptible to basement water damage.

That is why it’s essential to waterproof your basement. But how? You can waterproof your basement from the inside, outside, or both. Let’s talk about the right approach that best fits your basement.

Exterior Basement Waterproofing

When it rains outside, you carry an umbrella to keep yourself dry. Exterior waterproofing is like putting an umbrella on the outside of your basement walls. Except this umbrella won’t flip inside out on a windy day!

How Is The Exterior of A Basement Waterproofed?

Exterior waterproofing is applied to the outside of your basement walls. The exposed foundation exterior walls are cleaned, dried, and coated in a sealant. A waterproof membrane is then installed, followed by a drainage board. The excavated soil is backfilled to complete the installation. Exterior footing drains are also placed in the soil around the outer perimeter of the foundation.

Since the foundation needs to be exposed, exterior waterproofing is ideal for new construction when the foundation is still exposed. Unfortunately, for existing homes, exterior waterproofing requires digging a deep trench around your home to install the system, which may require removing landscaping, sidewalks, decks, and even HVAC systems.

“We do not recommend doing DIY waterproofing. Leave it to the professionals. DIY waterproofing systems are neither reliable nor long-lasting. Often, they can result in more water damage to your property and require expensive repairs. “

-Steve Karlik, Owner & Founder of Blue Umbrella Waterproofing

Advantages of Exterior Basement Waterproofing

Proactive Solution: Rather than waiting to remove water that’s already in your basement, exterior waterproofing is a proactive solution that prevents water from getting inside in the first place.

Structural Safeguard: With proper installation, exterior waterproofing can increase the life expectancy of your foundation walls. For existing homes, excavation allows for foundation inspection and repair of any existing damage.

Longevity: Professional exterior waterproofing requires little to no maintenance, making it an effective, long-lasting waterproofing solution.

Disadvantages of Exterior Basement Waterproofing

Landscaping Damage: Unless your home is currently being constructed, exterior waterproofing will require excavating around your home. OSHA standards state that for every foot you dig down, you must dig that far out from the foundation wall. This means digging a 7-10 foot deep and wide hole all around your home, disrupting any landscaping or property immediately around your home. Imagine an 8-foot deep by 8-foot wide trench around your house! Large machines, tons of mud, and upset neighbors

Disruptive Installation: Exterior waterproofing installation takes a lot of work. The excavation and application process is time-consuming and likely to disrupt your daily routine more than interior waterproofing solutions.

Lack of Protection from Seepage: Exterior waterproofing may help prevent the basement walls from getting wet, but it doesn’t take care of water seeping through the cove joint where the floor meets the wall inside the basement. Also, exterior waterproofing doesn’t solve the problem of water pushing up through the middle of the basement floor.

Clogging Issues: Exterior perimeter drains are placed outside your foundation walls during exterior waterproofing, but unfortunately, they can become clogged and stop functioning.

High Cost: Between the labor, installation time, and required materials, exterior waterproofing is much more expensive than other options.

Not Always Available: Not all homes have enough space around them for proper excavation, so exterior waterproofing will not be an option for all New Jersey homeowners.

Additional Exterior Solutions
On top of exterior waterproofing, there are additional measures you can take as a New Jersey homeowner to minimize the threat of water damage to your basement.

Gutters & Downspouts: Gutters and downspouts are your home’s first line of defense against heavy rainfall and snowmelt. Check your gutters regularly to ensure they’re clog-free and that all your downspouts are pointed at least four feet away from your house, preferably route them out to the street if your municipality allows

Property Grading: A negative grade in your yard will lead water toward your basement. Giving your lawn a positive grade will flow water away, reducing the risk of water pooling around your foundation and making its way inside.

Interior Basement Waterproofing

If exterior waterproofing is like putting an umbrella around your basement, interior waterproofing is like your house wearing a raincoat under its clothes. It keeps your basement dry from the inside and can also manage moisture levels. If water comes in, interior waterproofing makes sure it goes right back out. Interior waterproofing is the recommended solution for existing homes and properties.

How To Waterproof the Interior of Your Basement

There are various approaches to interior waterproofing, but the most effective is a complete interior perimeter basement waterproofing system. A perimeter channel is dug below your basement floor, and a french drain (4-inch PVC pipe) is installed. The interior french drain captures any water and channels it to a sump pump, which pumps the water out of your home at least 10 feet or more away from the foundation. The whole system is covered and sits below your basement floor.

Advantages of Interior Basement Waterproofing

Quick Installation: With no major excavation or construction required, interior waterproofing can be installed quickly and efficiently. Most systems can be installed within one to three days.

Minimally Disruptive: The installation process is kept entirely to your home’s basement without disrupting your landscaping outside.

Cost Effective: With less required time, labor, and materials, interior waterproofing is a less expensive but equally effective waterproofing solution.

Easy Maintenance: Because interior waterproofing is installed inside your home, it is easier to access for any required service.

Disadvantages of Interior Basement Waterproofing

Reactive Solution: Interior waterproofing is reactive, which means it does not stop water from getting inside your basement. However, it removes any moisture and keeps your basement as dry as exterior waterproofing.

Maintenance: Some parts of interior waterproofing systems, such as sump pumps, may need to be maintained or replaced over time.

Installation Inconvenience: While minimally invasive, interior waterproofing installation requires temporarily relocating items away from the walls in your basement. Your basement will also be available once the installation is complete.

Additional Interior Solutions
You can add extra interior protections to your interior waterproofing system to keep your New Jersey home safe and dry. These include:

Backup Sump Pump: A battery backup sump pump is a failsafe for your primary sump pump in case of failures or blackouts. While not mandatory, a backup sump pump is a wise choice to increase safety, home value, and peace of mind.

Dehumidifiers: A french drain system removes water from your basement, but a professional-grade AprilAire dehumidifier removes moisture from the air. It is a crucial inclusion for full basement protection.

The Difference Between Exterior and Interior Basement Waterproofing

Both interior and exterior waterproofing are effective, reliable solutions. So, how do you know which is right for your New Jersey home? Let’s compare them directly.

Comparing Costs & Longevity

Generally, exterior waterproofing is 7 -10 times more expensive than interior waterproofing. Both interior and exterior basement waterproofing methods can protect your home for many years.

Making the Choice

For the vast majority of New Jersey homeowners and businesses with existing properties, interior basement waterproofing is the correct way to go. We strongly recommend choosing interior waterproofing if your house or property is an existing build. This will minimize cost, disruption, and inconvenience.

If you are building a new home, then exterior basement waterproofing is ideal while the foundation walls are exposed, but for ultimate protection, we also recommend an interior system for new builds since exterior waterproofing does not prevent cove joint water seepage or through the floor seepage issues. For new homes, you can use interior and exterior waterproofing for comprehensive protection.

FAQ About Exterior & Interior Waterproofing

Can I DIY basement waterproofing?

We do not recommend doing DIY waterproofing. Leave it to the professionals. DIY waterproofing systems are neither reliable nor long-lasting. Often, they can result in more water damage to your property and require expensive repairs.

How do I know if I need basement waterproofing?

Signs that water is finding its way into your basement include visible water puddles, foundation wall cracks, damp and musty odors, efflorescence, bowed walls, and bug infestations.

How much does it cost?

Waterproofing costs vary, depending on whether you choose interior or exterior waterproofing, the size of your basement, and the complexity of installation. In general, interior waterproofing is much less expensive than exterior waterproofing. Blue Umbrella offers free estimates for our waterproofing services to give you a more accurate expectation.

How long does waterproofing last?

When installed by a professional waterproofing contractor like Blue Umbrella, interior waterproofing systems can last for decades. Interior waterproofing systems do not require much maintenance at all.

Do I need a sump pump if I have exterior waterproofing?

Exterior waterproofing attempts to keep water from ever entering your basement. While a sump pump is not required, it can provide extra protection in emergencies.

Contact Blue Umbrella For Your Basement Waterproofing Needs

Whether you want to waterproof your basement from the inside or outside or need help deciding which is best for your home, contact Blue Umbrella today. With thousands of satisfied customers, our team of experts is ready to protect your New Jersey basement from even the slightest hint of moisture.