If you want to know more about foundation crack repair, you’re in the right place. Find out what causes foundation cracks, the difference between structural and non-structural cracks, different foundation crack repair methods, and more.
What Causes Foundation Cracks?
There are two types of foundation cracks: structural and non-structural.
A structural crack is a foundation crack that threatens your home’s structural integrity. Structural cracks are caused by:
- Differential settlement – When a home is first built, it will naturally settle into the soil beneath it. This typical settlement is called uniform settlement and is very slight. Differential settlement is when sections of your home settle at different rates, creating sloping floors, bowing walls, sticking windows/doors, and mainly cracks.
- Hydrostatic pressure – Hydrostatic pressure is when water seeps into the soil surrounding your foundation. If you don’t have a proper drainage system to collect the gathered water, excess water will build up. The increase in soil volume pushes against the outside of your walls, forming cracks.
- Frost-heave – When soil freezes around your foundation, it can cause the dirt to rise. As the soil thaws, the dirt settles back down. The up-and-down movement will cause your walls to crack.
Structural cracks also form due to expansive soils, voids forming under your foundation, soil that can’t properly support a foundation, inadequately compacted soil, and improper grading that allows water to pool near your foundation.
Non-structural cracks are also called “waterproofing cracks” because they still allow water to seep into your home. A non-structural crack is a foundation crack that doesn’t pose a threat to your home’s structural integrity. They are usually found below I-beams, around windows, and in the corners of walls. Non-structural cracks are caused by:
- Concrete shrinkage – Concrete shrinkage is when a poured foundation dries too quickly, causing the concrete to shrink and form hairline cracks.
- Aging – Over time, homes can form foundation cracks simply due to aging. Foundation cracks formed by aging are small cracks less than 1/10 of an inch wide.
Structural vs. Non-structural Foundation Cracks
All foundation cracks are an indication something went wrong. Your main objective should be to find out whether your foundation cracks are structural or non-structural.
To tell if you have structural cracks, look for:
- Cracks wider than 1/10 of an inch.
- Cracks that look like stair steps in concrete block or brick walls.
- Cracks that run horizontally across your foundation walls.
- A series of vertical cracks running parallel to each other.
- Large diagonal cracks at the corners of your walls on both sides.
- Cracks running across your ceiling and down your walls.
To tell if you have non-structural cracks, look for:
- Cracks smaller than 1/10 of an inch wide.
- Vertical isolated cracks running from the top of your foundation wall to the bottom that do not change in size.
- Cracks found in a single block of concrete.
- Thin cracks near windows, corners of your walls, floors, or at longer sections of your foundation.
Foundation Crack Repair Methods
Below are the most commonly used foundation crack repair methods.
Structural cracks require more work than non-structural cracks. Repair methods include:
- Wall plate anchors – Wall plate anchors are used to correct bowing walls that cause horizontal cracks. These anchors consist of three parts: an inside wall plate, an outside anchor, and a high-strength rod that ties them together.
- Helical tieback anchors – Helical tieback anchors work the same as wall plate anchors except, they do not require an outside anchor or excavation. The helical anchor is drilled from the inside of your foundation and straightens your wall as the anchor twists.
- C-channel anchors – C-channel anchors are used for sheering block walls. A sheering wall is when the top of the basement wall has moved inward while the bottom of the wall stays put. C-channel plates help distribute the load across the whole vertical length of the wall. Instead of an inside wall plate, c-channel anchors use steel beams that are attached to the affected wall. Then, an outside anchor is connected to the steel beam using a high-strength rod. Lastly, the steel beam is anchored to your basement footer.
- Invisibeam carbon fiber straps – Carbon fiber straps are used to repair bowing walls which are causing structural cracks. First, the cracks must be sealed using an epoxy injection. Then, a galvanized bracket is installed to the top of your house frame. Third, the strap is attached across the wall and anchored to your foundation footer. Carbon fiber straps distribute the stress evenly and stop any bowing that may be occurring.
- Carbon fiber staples – Carbon fiber staples are used to repair both structural and non-structural foundation cracks. First, slots are grinded into the concrete to insert the staples. Then, they are fused into the concrete using a high-strength epoxy. Carbon fiber staples are usually used alongside epoxy injection.
- Steel push piers – Large structural foundation cracks are usually caused by differential settlement. Steel piers are pushed deep into your soil until they reach load-bearing soil. Then, using hydraulic jacks, your home is lifted back to the maximum practical level.
- Helical piers – Helical piers, also known as screwpiles, work the same way as push piers. Rather than being pushed into the soil, they are twisted like corkscrews. Read more about push and helical piers.
Although non-structural cracks don’t pose a structural threat, they can still allow water to seep into your home. Repair methods include:
- Epoxy crack injections – First, a surface patch is made using an epoxy bonder. Second, the crack is injected with a 2-part epoxy, waterproofing and reinforcing your foundation.
- Carbon fiber staples – Carbon fiber staples can also be used for non-structural cracks to ensure that they don’t grow larger. The staples are inserted using grinded slots and then fused with the concrete using a high-strength epoxy.
Foundation Crack Repair Cost
If your foundation cracks are non-structural and only require an epoxy injection, the price ranges from $500 to $900. If your cracks are structural, the price can be double the cost of normal crack repair, not including the cost of underpinning, carbon fiber repair, and wall anchors. Call a professional foundation crack repair company for the best estimate.
How To Prevent Foundation Cracks
Foundation cracks usually occur because water is draining toward your foundation. Poor drainage can lead to hydrostatic pressure, frost-heaving, differential settlement, and more. Learn how proper foundation drainage can help you.
The Real Seal
If you live in the Greater Chicago area and need foundation crack repair, who do you call? There are so many options out there. Who can you trust to provide quality service? You need the real deal, and you need The Real Seal. Call us today, and we’ll get you started with an in-depth inspection, free repair estimate, and a list of our finest solutions. We also provide basement waterproofing, crawl space encapsulation, crawl space repair, concrete leveling, and more.