How To Seal The Outside Of A House Foundation?

A solid foundation is always important for any property. However, some foundations are susceptible to cracking. Failure to seal these gaps can lead to problems ranging from small issues like holes in the wall to serious concerns like structural failures. So how can you seal the exterior of your home’s foundation? We researched for you and consulted with industry experts to give you the following answer.

The exact steps to seal a house's outside foundation often depend on different factors, such as the design of the property. Still, many of these jobs will generally require these steps:

  1. Excavate the earth near the foundation’s exterior wall.
  2. Remove leftover debris from the wall.
  3. Seal the wall using the appropriate sealing agent.
  4. Apply a bed of gravel over the seal and the plumbing.
  5. Cover the gravel with soil.

Bear in mind that not every crack you see in your foundation demands extensive sealing or waterproofing operations. Some gaps in or near the foundation don’t warrant concerns. Keep reading as we talk about the types of foundation cracks that require immediate attention. We'll also discuss the steps to seal the outside foundation of your home in greater detail.

Repairing a crack in the wall using a white colored sealant, How To Seal The Outside Of A House Foundation?

How Much Foundation Cracking Is Acceptable?

A relatively small crack or fissure in a foundation may not usually be a cause of concern. Homeowners should still pay attention to the shape, pattern, frequency of growth, and other factors of the foundation crack. That way, property owners can identify the best solution for the current problems on their foundations.

Here are some types of cracks that you need to keep a close eye on to maintain the structural integrity of your home:

Vertical Cracks

Many foundation cracks often have vertical orientations. These gaps can either be relatively straight or at a slight angle of about 30 degrees from the vertical plane. Additionally, many vertical cracks aren’t unsettling and are repairable using beginner-friendly DIY solutions like epoxy seals.

Check out this basement crack repair kit on Amazon.

Horizontal Cracks

Unlike vertical cracks, horizontal gaps are more serious and usually require immediate attention. Foundation cracks that travel sideways generally mean that the home’s foundation is facing serious issues with its structural integrity.

Take note that horizontal cracks can come from different sources, including exterior soil pressure and excessive water pressure. Moreover, these formations usually occur in homes with brick or concrete foundations.

Diagonal Cracks

Diagonal cracks can vary concerning the sizes of their openings. Some of these fissures have the approximate thickness of a typical strand of hair, which is commonly known as hairline cracks. On some occasions, diagonal cracks can also become unsettlingly large, particularly when the property is on a hill or incline.

However, diagonal cracks are still generally easier to prevent than horizontal fissures. One solution is to install gutters to ensure rainwater moves away from the lot’s foundation.

Take note that foundation cracking can appear in different areas, which can include the basement ceiling. Find out the reasons for the cracks on your basement ceiling is one of our posts to help you deal with this problem.

How Do You Seal A House Foundation?

A worker plastering the wall

Take note that sealing the outside of a home’s foundation can be quite expensive. Therefore, if you’re experiencing problems like basement floods, ensure that the issue is with the property’s foundation. It’s because these concerns may also come from other sources, such as faulty windows and plumbing problems.

But upon further inspection that you see that the problem comes from the lot’s foundation, you can proceed with the following guide:

  1. Excavate the wall around the exterior of the foundation. You may need to remove some roots from surrounding trees, which might also be causing unwanted pressure on the foundation.
  2. Clean the footer and remove the leftover dirt and debris that might still be sticking near the exterior wall. You can use a vacuum cleaner or a leaf blower for this step.
  3. Seal the outside wall with the correct sealant. For example, use a concrete sealer if the foundation primarily uses cement. You can also apply your preferred product liberally to ensure a proper seal.
  4. Apply a fairly small gravel bed under the perforated pipe to help protect the plumbing.
  5. Cover the gravel bed with a soil separator.

This project may also require doing some repairs on the property’s plumbing system. For instance, you may need to redirect the sump pump’s discharge. That way, the water doesn’t go into your home. Instead, the discharged water should travel to a connected sewage line.

You might also see some hairline cracks in your basement walls. If so, read our post regarding that matter to help you solve that concern.

Additionally, you can watch the video below to see the steps mentioned above in action. The clip also shows extra information on how to ensure a proper seal to an outside foundation:

Check out this gravel bag on Amazon.

What Do You Use To Seal House Foundation?

Base your choice of sealant with the house foundation’s primary material. Use wood bonding agents for wooden foundations or concrete sealants for those using cement.

You can also use caulk to close relatively small cracks. Most reliable caulks should cure in about 30 minutes, allowing you to proceed with sealing the rest of the foundation without waiting for the substance to dry for a long period.

Check out this caulk on Amazon.

Can You Seal A Foundation Crack From The Inside?

A worker applying sealant to the plastered wall

You can seal an interior foundation crack by applying a patch job. The basic steps for this project are:

  1. Use a rotary chipping hammer to remove the concrete in and around the crack.
  2. Clean the crack with a brush and/or vacuum cleaner.
  3. Patch the gap with epoxy or urethane injection then let the substance dry and cure.

Another option is to use hydraulic cement, which can harden through a chemical reaction with water. But this substance is usually ideal as a short-term solution. This cement can still crack, particularly when the fill doesn’t take up the entire gap.

How Much Does It Cost To Seal The Foundation Of A House?

Repairing and sealing a foundation costs about $2,318 to $6,750 on average. The overhead may also increase or decrease, depending on the extent of the damage to repair. Expect to pay about $2,500 or more for each leak to plug up or approximately $620 or over to seal cracks.

What Happens When You Don't Seal Concrete?

A mason applying a sealant on the cracks of the wall

Unsealed concrete can expand rapidly, causing structural damage to the foundation and the house. Remember that concrete is a porous substance that can quickly absorb moisture. Adding an appropriate sealing agent can help protect short- and long-term damage, which can also include corrosion and stains.

What Is A Good Sealer for Concrete?

Lot owners have different options to seal their concrete foundations. Some of these choices are:

  • Solvent-based sealants: high-gloss finish
  • Water-based sealants: matte or semi-gloss finish
  • Penetrating sealants: minimal to no luster

Homeowners should exercise regular reapplication of sealants to ensure their concrete foundations remain structurally sound. Applying the sealer at least once every few years can help prevent many foundation problems from surfacing.

Also, here are some options on the market for you to inspect:

1. Armor AR350

This concrete sealer can cover broad surfaces. A single coat can help seal 1,250 to 1,625 square feet of dense, trowel-finished concrete surfaces. The result of applying this product is a wet yet matte look.

Check out this product on Amazon.

2. ToughCrete Concrete Sealer

An eco-friendly choice, this silicone-based sealer can penetrate deep into concrete surfaces. Users can also use a brush or spray with this product for it to pierce deeper into concrete than normal. But this product might not be ideal for properties in reasonably wet climates as it may not resist moisture as well as other selections.

Check out this product on Amazon.

3. Siloxa-Tek 8500

This product uses an industrial-grade formulation with different uses. Users can apply this product on house foundations and other surfaces made from other materials. Aside from using it in concrete, this sealant is also compatible with brick and masonry. However, it often requires additional coats to provide optimal results.

Check out this product on Amazon.

Final Words

Repairing a crack in the wall using a white colored sealant

Property owners can seal the outside of their house’s foundations by excavating the soil surrounding the perimeter. Applying the correct sealant is next, along with protecting the exposed plumbing with gravel and soil. If done properly, the applied seal can help prevent structural damage to the foundation.

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