worker applies material for waterproofing the foundation

Here is a fact for homeowners: exterior basement waterproofing products are effective in stopping water from coming in. This way, you are keeping your basement dry while ensuring your foundation is structurally solid.

Why should you seal the exterior?

Heavy rainfall can be dangerous to a building with an unprotected exterior. And if you live in a flood-prone area, there is a number of ways water can breach into your house.

A wet basement exterior will definitely lead to wood rot, weakened foundations, and sagging floors.

But when you set up barriers against water, protecting your home from costly water damage is possible. 

Of course, sealing water effectively requires good waterproofing products.

Understand that when the exterior of your home is not waterproofed, moisture would likely seep into your basement, causing mold and mildew growth. This is dangerous to your health. 

How you should seal

When trying to stop water from coming in with exterior basement waterproofing products, there are several factors to consider. 


  • Identify the source


First, you have to know the cause of the water invasion. This requires identifying potential areas water can penetrate your building. This means purchasing waterproofing products to seal the external cracks and joints. 

Then you have to identify other potential leakage areas—installed light fixtures, wires or cables, for example—that can create gaps for water penetration. 


  • The proper outdoor drainage system


Installing an effective drainage system is your first line of defense against water damage.

From sloping your yard to divert water from your basement to installing window wells and French drains, proactiveness is key to your dry basement solution.

A clog-free drainage system is worth every penny. A good drainage system alleviates pressure on the walls and keeps your basement dry.

Likewise, your gutter system is critical to every exterior waterproofing goal.

The last thing you want is water pooling around your building and destroying your basement.

A terribly slopped or clogged gutter is a recipe for this disaster. 


  • Exterior French drains


Invented by Henry Flagg French, an exterior French drain is an important waterproofing product.

To install this drain, you need to drill a trench or hole in the concrete foundation.

Then you have to install a drain and sump pump to take water out.

By diverting excess water and protecting your exterior basement walls, a French drain is a reliable basement waterproofing product.

Along with French drains, vinyl sheets can be installed to keep water out. However, they are not always dependable and may slip off.

Amazon recommended French drain: Flex-Drain 51510 Flexible/Expandable Landscaping Drain Pipe, Perforated with Filter Sock, 4-Inch by 25-Feet


  • Downspout extension

Downspouts are vertically installed pipes that carry rainwater from your rain gutter. Because these pipes extend to the ground level, correctly positioning your downspout is vital to stopping water from coming in.

By installing a proper downspout drainage system, you can prevent leaks in your basement by reducing hydrostatic pressure against your building’s foundation. 

Amazon recommended downspout extension: Flex-Drain 85010 Downspout Extension, White


  • You might need to excavate 


Waterproofing your house is a job that begins on the outside. To protect the interior of your basement, you need quality exterior basement waterproofing products.

You might also have to excavate the perimeter of your building to use some of these products.

Exterior basement waterproofing is often best done during the construction of a new building, but older buildings can be waterproofed when the foundation is dug up.

By exposing the brickwork or concrete that makes up your exterior walls, you see the structural cracks or gaps. Remember to backfill the foundation. 

  1. Waterproof coating, sealers, and membranes

Coats, sprays, and membranes (rubber-based, asphalt-based) are great for waterproofing the exterior of your basement. These coats serve as a kind of waterproofing jacket for the basement exterior. These products serve as an added layer of protection you cannot do without.

Sealing the basement exterior with a coating is important because the exterior walls weaken over time. Purchasing the best sealer available in the market is crucial. 

An exterior waterproofing membrane creates an impermeable water barrier while creating structural integrity. By installing a drainage system along with this membrane, you are protecting your house. 


  • Hydraulic cement


Hydraulic cement, because of its expanding and restoring properties, is great for waterproofing. With hydraulic cement, you will be getting structural stability and reducing permeability. 

Amazon recommended hydraulic cement: Sakrete of North America 112611 10LB WTR Stop Cement


  • Epoxy injection


Hydraulic cement does a good job of filling cracks in the exterior walls. An epoxy-injection system can do a better job of giving you permanent protection. 

From pasty to ultra-thin, these crack injections come in a range of viscosities to fill cracks of different sizes.

Just understand that wider cracks require thicker injections.

Epoxies have this great compressive strength as well as a slow-curing property. This gives it time to fill up the tiniest crevice. On the downside, when epoxies are applied, it leaks out easily before curing. 

Amazon recommended epoxy filler: PC-Products PC-11 Epoxy Adhesive Paste, Two-Part Marine Grade, 1lb in Two Cans, Off White 160114


  1. Polyurethanes

Polyurethane foams, however, are fast setting and cure quickly. While polyurethane does not offer structural repair, it is a great waterproofing product. When injected crack, the foam effectively fills the void.

Amazon recommended polyurethane: RadonSeal Concrete Foundation Crack Repair Kit (10 ft)

  1. Sodium bentonite

Sodium bentonite, a clay material, can help fill cracks and absorb water. However, this product is not en vogue because it can clog outdoor drains. 

Amazon recommended sodium bentonite: 50 Pound Benseal Bentonite Drilling Mud Water Well Pond Foundation Seal Waterproof Baroid Grouting Wyoming Sodium Bentonite

Don’t wait for water damage

If your basement needs exterior waterproofing, getting the right product is crucial. If you are experiencing water damage, you have to act now.

Exterior basement waterproofing is a great form of defense when you have the right products. Investing in these products can save you a lot in basement waterproofing cost. 

  1. What a thorough article, unfortunately people often wait till the damage is done before even considering waterproofing their home. When I read that I may need to excavate, I’m not going to lie, I got a little nervous!


  2. Great article about waterproofing basements. I live in Ireland and we get a lot of rain, so not many new houses have basements. Tanking a base is very expensive here. You have good information regarding DPM and other waterproofing materials. I guess if you are considering taking on this kind of project you should consult a expert. Someone like you. All the best for the future and thank you for sharing this valuable information.

  3. Now I understand why my last place was always damp in the basement. I just thought it was because it was concrete lol

    I have learned a lot from this post. So thorough, not like my last builder. I will have my information ahead of time if there is a next time.


    • Hi Jo,

      It’s tough if your basement is always damp as this can cause many problems, including mold which can seriously affect your health.

      Take care,


  4. Very informative and beneficial content.
    Our house basement was damaged last year, and my father and I went through a lot of effort and money to fix it. I hope it never happens again.

    Thanks for this.


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