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Last updated: March 27, 2024 • Home Improvement

Comparison Between Interior and Exterior Basement Waterproofing

Unpleasant, damp, and cold basements often need to be more stable or limited to storage. Even the most minor threat of water intrusion frequently hinders homeowners from using their basements to their total capacity. Floods will remove everything from a dream home or any building. Moreover, structural integrity is prone to severe damage. Studies reflect that the need for basement waterproofing is increasing daily. 

This blog will help explore two crucial basement waterproofing methods: interior and external. A comparison analysis is drawn to help identify the better option available. Lastly, it will be concluded with a detailed description of factors contributing to final decision-making.

Table of Contents

Interior Basement Waterproofing

inside basement waterproof

As the name implies, interior waterproofing includes any work within the walls of basements. Numerous methods can be used to waterproof the basement internally.

  • The applied waterproofing method includes coating specific waterproof materials on the basement walls. Dry lock paints are used for this purpose. Such paints are formulated using a breathable formula that treats even the moisture trapped in the walls and provides full coverage against mold.
  • Moreover, crystalline solutions are applied to block larger cracks in the wall as these are an effective source of water intrusion. These solutions penetrate concrete walls and block the openings. However, concrete crack fillers are appropriate for small cracks. Let us assure you these materials are elastomeric. Thus, they can effectively seal the area.
  • The sump pump is another helpful method installed in the basement to pump the accumulated water to a place where it cannot harm.
  • Vapor barrier membranes are applied to the walls and floors to block liquid. They ensure good air quality in the basement. These membranes come in a wide variety, including polythene sheeting, foil-faced insulation, spray foam insulation, and many others. Depending on the wall’s condition, any type can be used.
  • Moisture often compromises the quality of air, which can be treated with the help of dehumidifiers. A good quality dehumidifier not only keeps the environment dry but also prevents the wooden structure of the basement from wrapping or rotting.

What Are the Pros of Interior Basement Waterproofing?

  • It is a cost-effective method of basement waterproofing as it does not require heavy digging or construction work involving labor and costly building materials.
  • It can be carried out at any time without any disruption to the neighboring property since it is done on the inside of the property.
  • It applies to all buildings or homes irrespective of the proximity of the neighboring property. Secondly, it reduces the requirement for the local authorities to prepare the necessary paperwork.
  • It can be installed at any time of the year as the work has to be carried out internally. Thus, it helps in executing the plans on time without any delays.

What Are the Cons of Interior Basement Waterproofing?

  • We warn you it is not a preventive measure. Instead, it can be applied once water has entered the basement, compromising the building’s structural integrity.
  • Humidity levels rise as the methods are being used internally to manage water. This leads to an extra cost of installing dehumidifiers to maintain air quality.
  • The interior techniques being applied require regular home inspection and maintenance to ensure their functionality.
  • It only addresses the current symptoms and does not cater to the cause of water intrusion. It does not eradicate the chances of occurrence from the source.
  • These methods depend on electricity availability and may fail in case of power outages.

Exterior Basement Waterproofing

exterior basement waterproof

House foundation problems can be extremely perplexing. Exterior basement waterproofing primarily covers the outer side of the foundation. It aims to keep water away from the foundation by using various strategies mentioned below:

  • One method is wrapping, which involves digging a trench around the foundation. Then, a plastic membrane is wrapped around the exterior wall to protect the basement.
  • Another method is exterior French drains, which redirect water away from the foundation. The gravel-free type is now applied using synthetic aggregated materials to replace gravel stone.
  • The guttering system of any home or building plays a vital role in waterproofing. An appropriate guttering system should be installed to divert rainwater away.
  • Slopes outside the foundation are necessary. This process, called grading, involves building a gentle slope around the foundation to ensure that the ground level is not equal to the foundation.

What Are the Pros of Exterior Basement Waterproofing?

  • First and foremost, the benefit is that the structural integrity is maintained with the help of exterior waterproofing. It refrains water from penetrating inside the boundaries.
  • The sources, instead of the symptoms of the issues, are identified and treated correctly. This protects the building or house from recurrent water damage and the additional cost of repairs at monthly intervals.
  • It protects from mold or mildew growth as the foundation from all sides is covered and prevents water intrusion.
  • Helps maintain the air quality as the basement is being covered from the outside, so the humidity levels inside the basement will remain low.
  • Since it is a permanent solution without frequent updates, it enhances the property’s resale value.

What Are the Cons of Exterior Basement Waterproofing?

  • It tends to be more expensive when the cost is concerned due to the extensive labor and materials involved in excavating the whole land around the foundation.
  • It can only be done during the initial construction as it can disturb your property’s landscape and the neighboring property.
  • Adverse weather conditions might delay the exterior waterproofing process, as everything has to be done under the sky. It cannot be planned for months in areas with extreme weather conditions, worsening the moisture situation.
  • It is a less feasible option for all types of properties as it requires ample space for excavation, which will not be possible with properties with limited space between buildings.
  • The structural obstacles also make it a less feasible option. Exterior waterproofing is always recommended during initial construction, allowing you to plan all the underground utilities or tree roots accordingly. Otherwise, this whole process will result in an additional cost.

Which Are the Main Decision-Making Factors?

direct decision making

All the factors regarding interior and exterior basement waterproofing are discussed above in detail. However, the clever homeowner must analyze the area around the foundation while making the final decision. They can also take in a few home improvement ideas from professionals. In the case of exterior waterproofing, there should be ample space around the foundation for excavating. 

Another factor to consider is the intended use of a basement. Suppose the cellar is used excessively for living purposes rather than storage. In that case, we recommend opting for exterior waterproofing, which will provide comprehensive coverage. 

Consider invasiveness!

The degree of invasiveness is another factor that should be considered when choosing an option. The interior waterproofing method requires the basement to be cleared before any procedure. In contrast, exterior waterproofing can be done without disrupting daily activities in the building. The basement clearance will be an added expense as extra labor will be required to move along with rented extra space to store everything for a limited time. 

It also depends on the nature of the issue the property owner faces. Suppose you’re only looking for a quick fix to the symptoms. In that case, interior basement waterproofing is the best option. If source identification is required, we suggest opting for exterior basement waterproofing

Reach Out to a Certified Waterproofing Expert!

written certified card

A professional should thoroughly examine the foundation’s condition before choosing any method. The interior waterproofing method can provide limited coverage against issues. At the same time, selecting an exterior waterproofing method is recommended for structural problems. It will treat issues like mortar joints, porous concrete, etc., more comprehensively, resulting in fewer to no foundation issues in the future.

The cost-benefit analysis is another deciding factor. If the homeowner has an excessive budget, they must go for exterior waterproofing, providing quality coverage from the source. Consider this cost an investment because it enhances the property value and reduces the cost required for frequent repairs. Nowadays, everyone knows the benefits of basement waterproofing and prefers owning such a property.


Ultimately, the choice between interior and exterior basement waterproofing depends on factors such as the nature of the water issue, budget considerations, and the desired level of protection. There are several factors to consider when deciding on home maintenance

It would be best to evaluate upfront costs, the system’s lifespan, ongoing maintenance costs, and how long it will remain effective. Generally, exterior work (except window wells and guttering) will last longer and need less ongoing maintenance than interior solutions. However, they will also be considerably more expensive, especially wrapping. 

A professional assessment can provide tailored recommendations based on your property’s unique characteristics.


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