How Serious Is A Crack In The Foundation?

By Mike Holmes

Mike’s Advice / Buying & Selling Your Home

Monday, November 21st, 2022 @ 9:15am

How To Tell If Crack In Foundation Is Serious

When talking about foundation cracks, we mean vertical AND horizontal cracks found in the walls or floor of your home. Most of the common basement foundation cracks occur around basement windows and doors as it’s a “void” in the foundation wall. A well-designed foundation supports the house and diverts water away from the structure. And what do I always say about water? It’s your home’s #1 enemy. 

When concrete cures or dries, it can crack. If you’ve just laid a new foundation and see a few small cracks, don’t panic. Mark them with tape, and check back in a few months. If the cracks aren’t growing, they can usually be filled with an epoxy injection or expandable foam.


Mike Holmes inspecting a big vertical foundation crack on the inside of a home.

Inspecting a big vertical foundation crack on the inside of a home we worked on.


Foundation problems are one of the most expensive issues to repair when it comes to your house. Here’s a guide on how to fix cracks in your foundation.


Types of Foundation Cracks

Horizontal Cracks in Your Foundation

Horizontal cracks are serious, and I want you to look into repairing your foundation if you have a horizontal crack. These are caused by the soil [mainly clay] constantly expanding and contracting. This puts the basement walls under a lot of pressure. You may even notice some walls bowing. 


Cracks In Your Floor

Generally speaking, foundation floor cracks are caused by the building settling, poor drainage of the surface, or leaks coming up through the floor. You will need to look into your drainage systems and pumps, and weeping tiles




What To Do If My Basement Floods

Cracks In Your Foundation Walls

Damage to foundation walls can be caused by a few different things. It could be shoddy construction, water damage or settlement. You will likely need to apply sealants, epoxy injections, and/or hydraulic cement, and provide drainage and waterproofing to stop any more damage.


Mike Holmes Foundation Crack

Structural Foundation Cracks

A structural crack is where the foundation wall feels uneven or the width of the crack is about ¼” or wider. If you have a structural foundation crack, you may need an engineer’s specifications to do a basement foundation repair. 


Why Is Foundation Crack Repair Important?

I always say when it comes to your house, fix it from the outside in. It is VERY important to inspect your foundation for cracks. All cracks are not serious, and I’m going to get into that as well.

Any damage to your home’s foundation is not good. If left untreated, foundation cracks can become bigger and bigger, and compromise the structure of your home. 

The bigger the cracks are, the more they can compromise the integrity of your structure and the more expensive they will be to repair. 


Signs of Foundation Problems

These red flags may indicate you have a problem with your foundation:

  • Windows and doors that once operated properly now stick, rub, or do not open or close properly.
  • Floors that have noticeable dips
  • Cracks appearing at the corners of door frames and window frames
  • Gaps appear between the base moulding and the floor covering


What Does It Cost To Repair A Foundation?

You are looking at around $4000-$5000 to repair a structural basement foundation. Cost can be higher if the foundation repair requires the involvement of machinery and engineers. Depending on the scope of the project, it could cost you $10,000-$20,000. 

That’s why I am always talking about doing seasonal home maintenance and catching these types of things earlier. 


Any damage to your home’s foundation is not good. If left untreated, foundation cracks can become bigger and bigger, and compromise the structure of your home. 


Exterior Waterproofing

When my son was renovating his home, he found some major cracks in his foundation and big repairs became a necessity. If you can fit a coin in any of the cracks, it’s time to waterproof it from the outside.

rcc waterproofing

Exterior waterproofing is a process that waterproofs and seals foundations by bridging cracks or faults caused by movement. The company we use (RCC Waterproofing) uses a commercial-grade product, Hydro Guard. It is typically a two-layer application method. This costs $200-250 dollars to cover 20 feet.

This is a commercial-grade waterproofing product, so RCC can actually offer a 50-year protection against water penetration. Talk about peace of mind!

waterproofing on the exterior


Benefits of Exterior Waterproofing:

  • Makes the foundation of your home stronger
  • Peace of mind that your home’s structure is sound
  • Reduces moisture in your basement. Excess moisture leads to mould, rot and indoor air quality issues.


Can I Repair My Basement from the Inside?

Worried about hairline cracks on your foundation walls? Not all foundation cracks are serious and it is possible to fix a leaky basement from the inside. Hairline cracks can happen because of minor settlement of the house or just seasonal expanding and contracting. 



House Foundations Explained


What is the Best Foundation Crack Repair Kit?

Big cracks in your foundation might be a sign of a serious issue. It’s best to call a professional to take a look and assess the work needed. However, smaller vertical cracks are common due to the shift and movement of your home’s foundation —but they still need to be fixed as part of your regular home maintenance.


Mike Holmes With Sika Foundation Crack Repair Kit

Love this Sika Foundation Crack Repair Kit. It comes with everything you need inside the box to get small cracks repaired.


If you’re a seasoned DIYer or handyman or even a contractor, I recommend the Sika Foundation Repair Kit. This product is great and simple to use, and it provides you with everything you need inside the box to do a foundation crack repair. That includes injection tees, quick-setting cement, and a polyurethane injection foam. Plus, you can scan the QR code on the box and watch a video of the installation —it’s that easy to Make It Right!



How do you know if a foundation crack is serious?

Hairline cracks are not an indication of a major issue. If the cracks are large, you should have an expert come out to check them. The National Association of Home Builders (NAHB) standard for cracks in interior slabs requires repairing cracks that exceed three-sixteenths inches wide or high (vertical displacement).


To be honest, only a professional can determine what cracks need repairs and which ones you don’t need to worry about. 


When Should I Hire a Foundation Repair Company?

Some foundation problems are simple cosmetic problems, others require the services of a professional foundation repair company.

A good foundation repair company will restore your foundation walls and floors back to a strong and structurally sound state. This means free from any cracks or defects that will allow moisture to enter your house.


Be mindful of the products used for waterproofing your home. I’ve seen some companies advertising waterproofing services, but what they are actually using are damp=proofing products (which are cheaper for them). I recommend RCC Waterproofing for exterior waterproofing jobs. We have worked with them for several years, and in my opinion, they are thercc waterproofing best in the business.


In exterior damp-proofing, a liquid asphalt-based product is applied thinly to your foundation. As there is no rubber, damp proofing does not provide any crack-bridging capabilities. Typically, damp proofing is only done to meet the minimum building code requirements. And you know I always build above minimum code. 



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