Should You Waterproof the Inside or Outside of a Basement or Crawl Space?

Ebonee Williams
Written by Ebonee Williams
Updated October 13, 2021
The basement of a house used as a playroom
Photo: Iriana Shiyan / Adobe Stock

Noticing moisture in your basement could be the early signs of a significant water issue and should be investigated quickly

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Keeping your basement or crawl space free of moisture is of the utmost importance. After all, excess moisture can lead to all sorts of problems, including mold and foundation issues, and even ruin game rooms and boxes of holiday decorations in the process. 

The best way to handle moisture problems is by implementing interior or exterior waterproofing methods. But how do you decide between them? We’ll cover everything you need to know to keep your home safe and dry.

Exterior Waterproofing Pros and Cons

Exterior waterproofing methods stop moisture from creeping into the walls from the outside. Waterproofing the exterior of your home involves removing the dirt around the basement and adding materials that act as a barrier to keep everything dry. Depending on the nature of the damage, exterior waterproofing may be best.

Exterior Waterproofing Pros

This method could be a winner if you’re like most homeowners and use your basement for storage. We recommend this method for homeowners who prefer to have work done outside of the home versus inside. Since everything is done outside, you’ll be able to keep your things in the same place. Pros will use French drains on the exterior, and this process can be an ideal solution to protect your home from flooding and water damage.

Exterior Waterproofing Cons

This method is the most expensive way to waterproof your home because it’s more labor-intensive. You’ll need to install drainage systems to keep water away and do lots of digging to set up the system. Although you won’t have to worry about moving indoor furniture, you may have to remove anything surrounding the perimeter. These systems aren’t a one-and-done installation. Over time, they can become clogged, so they require a lot of maintenance and upkeep.

Interior Waterproofing Pros and Cons

A worker waterproofing the crawl space of a house from the outside
Photo: MyrKu / iStock / Getty Images Plus / Getty Images

In the past, homeowners and many contractors preferred exterior methods to interior waterproofing because it seemed more secure. But now, some interior techniques can be just as effective and can save you money.

Interior Waterproofing Pros

Interior waterproofing is less expensive since it’s easier to access, has a quick installation process, and overall requires less labor. With interior waterproofing, you don’t need to do any intense digging or removing dirt from the exterior of your home. Pros can install devices like sump pumps to help remove water from crawl spaces and basements.

Interior Waterproofing Cons

You’ll have to remove furniture and any cabinets built into the walls for interior basement waterproofing. Sump pumps can be a great option. But they often get filled with rocks, dirt, and sand, which cause the unit to malfunction. A qualified local plumber can run a camera into your sump pit drain lines to see if a blockage or other issues is affecting the operation of your pumps.

It’s important to take care of water issues immediately as they not only cause structural damage to your home but can also be the cause of major health issues for your and your family. Moisture in your home can come from multiple sources, so make sure to check things like the air quality and humidity levels to ensure a safe home environment.

Exterior Waterproofing vs. Interior Waterproofing

Take a look at how exterior and interior waterproofing methods compare side by side.


Exterior waterproofing stops water from getting into your basement from the outside and protects your home’s foundation. Interior waterproofing removes water from your basement or crawlspace, but only after water accumulates.

Most durable waterproofing: Exterior waterproofing


Waterproofing your basement from the interior costs less than exterior waterproofing because it requires less work and fewer materials. In the long run, you’ll save money with exterior waterproofing because it’s more efficient.

Most cost-effective: Exterior waterproofing

Ease of Installation

Installing exterior basement or crawlspace waterproofing is more labor-intensive. It involves excavating the outdoor areas surrounding your home. You’ll probably want to hire local basement waterproofers to help with this process. Interior methods are less invasive, and pros can do this pretty quickly. 

Easier to install: Interior waterproofing

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