Bowing Basement Wall Repair
A bowing basement wall is a convex shape of the basement wall, an inward inflection.
Hydrostatic Pressure As The Main Cause For Having A Bowing Basement Wall
Water accumulation near your foundation percolates easily down through the foundation fill that was loosely pushed in place, but then the water slows its migration considerably when it contacts the normal hard-packed and undisturbed soil surrounding the fill.
This is particularly bad if the surrounding undisturbed soil is heavy clay. When the loose-fill is fully saturated (which is what usually happens when it rains hard over several days or you experience large snow melts), it exerts a considerable force against your foundation wall.
Imagine that you have a moat around your foundation walls that is 7 or 8 feet deep and 3 to 5 feet wide at the top, narrowing to 1 to 2 feet at the footing. Indeed, it would push your basement wall in. This will cause to have a buckling wall, a basement wall that is caving in gradually.
I have seen also in many properties wherein a bowing basement wall is identified,that a drain tile was either never installed around the outside footings or they were installed, but are now silted in with soil or the drainage is blocked.
Rerouting Water Away From The Foundation Wall
The homeowner’s goal here is rerouting water away from the foundation wall, as this is the source of the excess moisture that ends up pushing against your foundation walls and generating a bowing basement wall gradually.
The homeowner should likewise ensure that the grade from your house slopes away from the foundation walls, as this will help divert some of the moisture from percolating down.
As to the bowing basement wall issues matter, your goal as a homeowner is to reduce the external hydrostatic pressure, the lateral pressure suffered.
You cannot hope that there is enough back spring in the wall to bring it back to its original position. Even in summer when the rain stops, depending on your location, and the ground dries out and shrinks, the basement will keep its inward curve and you should be searching for complete remediation.
The soil that stands around your property absorbs rainwater and becomes expanded towards the foundation. This expansion is not downwards, as gravity, but lateral. To the walls of the foundation. This lateral pressure originated by the expansion of soil because of water absorption is the hydrostatic pressure.
Runoff from gutters and downspouts are a source of water to increment the hydrostatic pressure.
If roof runoff is not directed away from your foundation, the soil around the foundation will become heavier and more expansive as it’s saturated with water.
If it isn’t directed away from your home’s foundation, it can become oversaturated with water. The soil is heavier which is why it’s able to shift, bow or buckle the foundation.
Influence Of Soil Types In The Bowing Of A Basement Wall
Exterior soil adjacent to the side of the basement wall becomes saturated with water during rainy times. This waterlogged soil becomes heavy and expands. This expansion pushes against the basement wall from the outside.
This problem of hydrostatic pressure is more pronounced with expansive soils—those that are rich in clays. The U.S. Midwest, South, and California’s Central Valley are heavy in clay soils. Sandy soil drains well and is not expansive.
Clay soil readily expands and contracts in accordance with moisture changes in the ground. The expanding and shrinking can result in differences in pressure and cause the basement walls to curve.
Other Related Causes For Having A Bowing Basement Wall
Poor Yard Drainage As A Cause For Having A Bowing Basement Wall
Usually caused by poor yard drainage. This water adds weight to the soil and forces pressure on the walls of your basement. Over time this pressure can cause the walls to crack and buckle inward weakening the structure of your home and potentially causing basement water leaks.
Let´s go through lateral pressure and hydrostatic pressure below. You are not wrong if you are thinking that all these causes are very much related and that poor drainage in your yard is the mother of all causes for having a basement buckling wall.
The reason why foundation walls bow and buckle depends on the amount of pressure soils place on the structure. Here are four common factors that cause issues structurally:
- Soil type plays a big factor. Different types of soil create issues for foundations.
- The amount of moisture the soil contains. Less moisture is key.
- The location of the foundation. If it’s further underground, there can be bigger issues.
- The temperature. Hot and cold weather can cause soil to collapse walls or cause them to lean.
Basement walls are designed to support your home, which exerts pressure from above. The soil around the foundation presses in from the sides. In the foundation industry, we refer to this as lateral pressure.
– When soil freezes, it expands and this exerts pressure against the wall.
I described thoroughly above that hydrostatic pressure in the basement is the main cause for having a bowing basement wall.
This constant (or at least seasonal) pressure can build up against your basement walls over time and cause them to crack, bow and buckle inward. In turn, this can weaken their load-bearing capacity and eventually threaten the structural integrity of your whole house. The damage can range from a few superficial cracks to severe visible inward bowing and separation
The combination of lateral and hydrostatic pressure? Highly problematic. Your foundation isn’t always going to be an immobile object. If your soil exerts enough pressure, your foundation can “give” a little bit and crack. And once there’s a weak spot, pressure will continue to win the battle.
In the past, the only way to fix a buckling wall was to replace it. Fortunately, there now are methods that don’t require invasive construction. Some of them don’t even need excavation- the walls can be repaired from inside your basement.
Parking Of Heavy Objects Nearby
Extremely heavy items placed on top of the soil adjacent to the basement wall can push down on the soil, which also has the effect of pushing the soil outward. Ordinary exterior items such as decks will not cause this, but heavy machinery or vehicles parked long-term may cause this.
The inward curve of a bowing basement wall is normally due ti the hydrostatic pressure but we cannot discard completely a general foundation settlement issue.
How Much Bowing Is Acceptable On A Basement Wall?
Two inches is considered minor deflection. From 2 to 4 inches is moderate deflection; this can be corrected with tie-backs, wall anchors, or steel beams. Walls that deflect 6 inches or more are severely bowed and often must be replaced.
As a rule of thumb, basement walls that are bowing in can be reinforced to prevent further movement. Note: up to 2″ of inward bowing or less is required, anything beyond that and your wall is no longer structurally sound and should be replaced.
As a general rule of thumb, when a wall is bowing or tilting inward more than 50% of its thickness – For example, an 8” thick wall bowing in more than 4” – the wall almost always needs to be demolished and replaced. Therefore, if you see a crack, or any movement whatsoever in a wall – no matter how slight – you should contact a foundation repair professional immediately for an inspection. In other words, you should never leave a wall unrepaired to the point where it ends up bowed. Any cracks or inward movement of a wall are not OK. The sooner you catch the problem, the less expensive it will be to fix.
I have a complete article about how much is the acceptable bowing on a basement wall, how to measure this curvature with a plumb, and which decisions to take afterward.
Expected Loads On A Bowing Basement Wall
Hydrostatic overloading is a common cause of wall failure, but it is not the only cause and we have to analyze the functions of a basement wall and the distress that it can withstand as per design. For example, for a 10 high wall, free groundwater will increase the loads on the wall by 25 to 30 percent.
A basement wall is a restrained wall. That means that the top of the wall should not move at all. If it does, it will shift whatever is sitting on top of it.
The typical retaining wall that you see is an unrestrained wall, it is designed to tilt slightly to allow the soil to carry some of the load and it is a safe foundation.
This is where the two-inch deformation rule of thumb comes from. A typical description of the distress suffered by a bowing basement wall is consistent with an unrestrained wall acting as a restrained wall. The normal soil loads on the wall caused it to tilt, but the house framing prevented the top of the wall from shifting.
Therefore, the upper part of the wall cracked and bowed outwards, while the middle part buckled or has caved in. The deformation that translates into an inward curve is permanent. It will not ‘spring back’ once the water table lowers, or the hydrostatic pressure disappears.
The problem with unrestrained walls and clays is that initially, the wall tilts, and the soils carry some of the load, as it is supposed to by design. Over time, many years, the clay soil creeps towards the wall, increasing the soil loads on the wall. The wall then tilts in response to the higher loads, as it is supposed to as per design, and the entire process begins again.
Over 30 to 50 years, this process can cause a wall to tilt 1 to 2 feet.
Before you do repairs, you need to determine if the wall tilting was caused by hydrostatic loading or hydrostatic pressure, or an underdesigned wall.
If it is hydrostatic pressure, it would have occurred quickly in response to very heavy rainfall. This happens too in crawlspaces, they get flooded frequently, but only after a heavy rain, instead of standing puddles of water.
Is the basement wet? Are there indications of water flowing through the wall, was there a very wet winter, is there a roof downspout just above the damaged section of the wall, the bowing wall? Has the bowing basement wall process been going on for several years?
Is there reinforcing steel within the wall? Something anchoring or underpinning the wall such as an anchor, a helical tieback, or a Powerbrace treatment?
If not, then exterior reinforcement will be of little help as there is nothing for them to support. The best thing to do is rebuild the wall as a restrained wall.
A bowing basement wall must always be identified during an inspection because the inward inclination scrutiny must be included in the inspection checklist. In this situation, a 2″ inclination is expected as the acceptable bowing for a basement wall.
Bowing Basement Wall Repair Cost
customers paid an average of $5500-$6500 for these services. Three things will influence the overall cost of repairs to your home: how far has it bowed, what is outside of the wall, and how long the wall is. Each of these is contingent on which repair option you choose to use.
A wall that has bowed less than 2” can be repaired with carbon fiber strips applied to the wall using industrial strength epoxy for about $5,000.
If, instead, the wall has moved more than 2”, steel strips will need to be installed and anchored to the floor joists for as much as $15,000. Here we can utilize a wall anchor or a helical tieback.
The difference between those repair methods is which one is a better fit for your property. Anchors need to be installed outside the foundation, about 10 feet away from the wall. If you don’t have the room- or something very important is installed at that location- tiebacks are a better option.
I have two detailed articles about foundation repair cost and very specifically about basement wall repair cost that cover thoroughly the issue of having a bowing basement wall, as the similar issue of the basement wall that caves in, or that buckles inward.
Costs Of Repairing A Bowed Basement Wall In Relation To The Severity Of The Issue
The cost of repairing both basement walls depends on the severity of the bowing and the area where you live.
Walls that bow farther inward require different, more expensive repair methods, which may include extensive outside digging. If you live in an area where many basements experience bowing, there is a more active market for this type of work—so, more choices for you and the potential of receiving competitive bids.
- Low: For basement walls that bow only slightly, the cost of repairs may run between $4,000 and $8,000.
- Mid: For mid-range wall bows from 3 to 4 inches, the cost could run between $8,000 and $15,000. If helical tie-backs are required, each tie-back can cost as low as a couple hundred dollars to $1,000, with total project averages running around $18,000 to $20,000.
- High: Severely bowed basement walls with 6 inches or more of deflection likely will cost $25,000 or more to fix, as the entire basement wall would need to be replaced
Symptoms Of A Bowing Basement Wall
Sometimes you can visually notice a bowing basement wall. Also, you can measure this inward inclination with a plumb.
Horizontal or stair-step cracks are common when a foundation wall tilts or bows. If your foundation wall is made from concrete blocks, you might notice diagonal cracking between individual blocks.
If the wall is poured concrete, the most common type of cracking is diagonal. The cracks will generally start at the top of the wall, and angle back toward the nearest corner. If the foundation walls are brick or block, then the more common cracking pattern is a horizontal crack toward the mid part of the wall, then stair step cracking once you get close to the corners.
Cracks in the walls that are wider at the top than at the bottom
Uneven Windows And Doors
A more subtle yet still useful identifier of bowed and buckling foundation walls is an unevenness in your home’s doors or windows. Your foundation and your home overall aren’t built to accommodate significant shifts in the ground. When hydrostatic pressure exerts enough force to push the foundation out of its original position, the frames of the windows and doors can become misaligned with the windows and doors themselves. As a consequence, when you try to open or close them, you may face more resistance than usual or find they simply don’t swing or slide into place as they should.
Expansive Clay Soil
- Wet, clay soils around the home coupled with damaged walls
- Expansive clay soils present around the structure
Other Symptoms Of A Bowing Basement Wall
- Floors that are not level
- Doors, cabinets and windows that do not shut properly
- Cracking in the upstairs plaster and/or drywall
- Cracking in exterior brickwork and/or caulking
- Leaning of outside chimneys and/or porches
Repairing Processes Against A Buckling Wall
Below we will analyze three repair methodologies that are uses against a buckling wall, depending if the curve angle is less than two inches ( carbon fiber straps) or more than two inches (mainly wall anchors or helical tiebacks).
These methods below will ensure to stop the advance of the inward curve for the buckling wall. If you want a permanent solution and strengthen back your basement wall, then we have to decide for wall straightening, which is studied below here.
Repairing Processes Against A Bowing Basement Wall With Less Than Two Inches Of Inward Curve
Carbon Fiber Straps
If your wall has bowed or buckled less than 2 inches, carbon fiber straps are your best option. These are the fastest and easiest to install, requiring no excavation or exterior installation.
Carbon fiber straps are also the least expensive repair method. They are incredibly strong fibers woven together and adhered to your foundation with epoxy.
The epoxy glue is injected and will fixate the carbon fiber straps.
After the installation process has finished, these carbon fiber straps can be painted matching the color of the wall and you can forget that they exist.
Carbon fiber is an extremely strong fabric material that doesn’t stretch and is virtually unbreakable. This makes it perfect for repairing bowed walls. The installation is fast, clean, and the straps can be used to stabilized both block and poured concrete foundations.
The carbon fiber straps are placed on the wall approximately every 4’, on center. The term ‘’on center’’ means the distance from the middle of one carbon fiber strap – or any other element – to the middle of the next.)
The average repair job using carbon fiber wall straps takes 1-2 days to complete.
While carbon fiber straps work well for wall stabilization, they don’t straighten the wall. However, since they’re only 1/4” wide and can be painted after the job is done, you will hardly know they’re there.
The process is to attach the carbon fiber frame to the top of the house frame, along the walls, and at the foundation’s footer. This network of carbon fiber pieces serves to distribute the outside pressure evenly across the foundation, putting a stop to unwanted shifts. The carbon fiber will hold up in the long term as well; it’s strong and unaffected by temperature changes.
A big advantage of using an externally applied, carbon-fiber reinforcement grid system is the speed and ease of installation. It permanently stabilizes bowed foundation walls with minimal disruption, no excavation, can be used in lieu of tiebacks, and is much cleaner than alternative techniques. Installers apply the crack repair epoxy through a static mixer, so no measuring or mixing is required. Once the epoxy cures (generally after 1 hour depending on temperature), the process is complete.
Be aware that not all carbon-fiber systems are installed the same way: some do not attach to the sill plate or floor and others have a necktie that attaches to the sill plate, but the strongest systems link the foundation base with the house framing. This is done by using a galvanized sill plate tie as well as a pin anchored into the footer.
In order to achieve the maximum benefit of carbon fiber, it needs to be properly connected to the structure’s foundation. It is necessary to attach the carbon fiber to the structures footer and to the sill plate. By tying the carbon fiber into the structure at multiple points, the stress placed on the foundation is evenly distributed. It is unsafe to only strengthen the wall at the point where it is bowed the most because you are shifting the stress load to a different part of the foundation; this causes the wall to shear at the bottom or collapse inward as a whole.
Benefits of Using Carbon Fibers for Bowing Basement Wall Repairs
For homeowners, a carbon fiber system offers several key benefits:
- It is guaranteed to permanently stabilize foundation walls against lateral loads.
- Installation is fast with minimal disruption and mess.
- No excavation of property is necessary.
- It does not create obstructions in the room that can reduce floor space.
- The reinforcing material will not corrode, mildew, or weaken over time.
- The repaired surface can be painted or covered with white wall panels.
- The home maintains a higher resale value than when repaired with more obtrusive steel alternatives.
A carbon fiber repair that is properly linked to the foundation and house framing comes with peace of mind that there will be no further damage. Carbon fiber crack repair is a 12 wide repair that not only stops water infiltration but strengthens the foundation, preventing future cracks from developing. The repair is wide enough that it covers the main crack as well as any fractures or hairline cracks. This is important because what may be a hairline crack inside the basement is typically a much wider crack on the exterior.
Cons Of Installing Carbon fiber Straps To Mitigate The Effects Of A Bowing Basement Wall
Carbon fiber straps help stabilize the wall when working in conjunction with water mitigation measures.
Just by installing carbon fiber straps is not a complete correction of a bowing basement wall.
Carbon fiber straps do not remove the pressure causing the damage in the first place. Instead, it transfers it to other portions of the wall. Carbon-fiber reinforcement is widely used when there is only a small amount of damage. Helical tiebacks should be used in cases of moderate to severe movement and are often accompanied by the use of carbon-fiber systems.
How Are Carbon Fiber Straps Installed
Here is an overview of how such a system is installed:
- First, the foundation wall is prepared, which includes marking the position of each carbon-fiber strap and grinding vertically where they will be applied
- Second, the holes for the sill plate tie are marked and drilled
- Third, the sill plate tie is attached to the carbon-fiber strip
- Fourth, the sill plate tie is mounted in the pre-marked position
- Fifth, the strip is epoxied to the wall
- Sixth, the carbon-fiber pin is anchored into the footer and epoxied in place
Here are the supplies and tools typically used for the installation:
- Supplies: Carbon fiber straps, epoxy adhesive (in tubes), carbon fiber pin
- Tools: Grinder, power drill with ¼” and ¾” bits, hammer, level, caulk gun and nozzle, squeegee
- Hardware: Sill plate tie bracket, (2) 3/8 x 2 lag bolts, (2) flat washers
- Other: Marker, gloves, tape measure, scissors
Conclusions about the carbon fiber strap methodology against a bowing basement wall:
Carbon fiber fabric installs in tough strips on the foundation walls in order to reinforce the weakened areas. To install these, the areas where installation will occur are treated and applied with epoxy glue. Carbon fiber fabric strips are installed on the treated areas and the installation is complete. The installation is fast and relatively inexpensive.
This installation is better than some options, however it is also without its weaknesses. Because these strips are not installed along the entire length of the wall, the bottom portion of the wall can still crack and shift and the top portion of the wall can still be pushed inwards, causing leaning foundation walls. The installation relies on epoxy glue to be successful, and the carbon filter fabric cannot be used to fix walls with severe cracking or displacement. Finally, this method of foundation repair also cannot restore the wall to its original position as foundation anchors can.
Carbon fiber strap stabilizers are sometimes installed after the basement wall bowing has been corrected.
From the outside, soil is excavated to provide working access. Then, on the inside of the basement, hydraulic jacks push the basement walls outward to correct them. Once corrected, the walls are strapped.
Steel I-Beams don’t require excavation and are designed to straighten both block and concrete walls over time.
They are placed on the wall approximately every 4´- 5’, on center. The average job using steel I-beams takes 1-2 days to complete.
At the bottom, the beams are bolted into the floor. At the top, the beams are bolted to the house’s joists or beams.
Steel beams are attached in conjunction with excavating soil alongside the wall exterior. This is necessary so that the wall can be pushed back to vertical and corrected. Since the beams remain in place, this is best for unfinished basements.
Repairing Processes Against A Bowing Basement Wall With More Than Two Inches Of Inward Curve
If your wall has buckled more than 2 inches, you will need either anchors or tiebacks. The decided factor between these two methods is your property’s size and shape.
Wall anchors are usually called also wall plate anchors because the plates are a very visible component.
Just note that sometimes there is not enough space to install wall anchors so the solution would be there to install helical tiebacks, less visible but quite more expensive too.
–Wall plate anchors are placed on the wall approximately every 5′, on center.
The average wall plate anchor system takes about 1-2 days to complete.
For basement wall bows that deflect up to 2 inches, wall plate anchors are a good option. Large metal plates are fastened about every 5 feet (5 ft on-center), along the basement wall. Steel rods extend horizontal and level at least 10 feet outward from the basement and are secured in the ground.
Wall plate anchors require substantial exterior digging. If you have any obstructions in the 10-foot wide border around the house, such as easements or sewer lines, you cannot install wall anchors.
Wall anchors require excavation into your yard, usually about 10 feet past the damaged basement wall. If this doesn’t cross your property line, or intersect with something significant (inground pool, septic system, garage, porch, etc), anchors are a good option.
Otherwise, wall anchors are an effective, permanent solution to bowed basement walls. Plus, they allow stud wall systems to be built on the inner basement walls—important if you want to finish the basement.
Wall anchors can repair many bowing wall problems. Soil anchors are placed in the ground outside the home.
Steel rods attached to soil anchors extend through the foundation wall and wall plates.
Wall plates distribute clamping pressure. Tightening nuts on the threaded ends of the rods stabilizes the wall for a permanent solution.
These are a 3 part system consisting of 2 plates and a long connecting rod. We start by driving a long steel rod into the ground through a hole we drill in your foundation wall. The first plate is driven into the ground outside your home, 10-15 feet from your basement wall to ensure it is driven into virgin, undisturbed soil and over the rod we’ve placed through the ground. The second plate is inside your basement, attached to the rod (which is anchored on the outside plate) and slowly tightened to pull your bowing wall back into place. The tightening may require multiple trips for our team to tighten the plate and ensure your wall is back in its original location properly supporting your home.
As you can see from the illustration below, a large plate is buried in your yard- this is the anchor. A plate is attached to the damaged wall, and a post is drilled from the wall into the anchor. As it’s tightened, it pulls the wall plate and the wall securely together.
Wall anchors are designed with three main parts: an exterior earth anchor, an interior wall plate, and a connecting steel rod that. Together, they work to counteract the pressure being exerted against the wall.
When foundation anchors are installed, a small area of lawn is removed, and the space underneath is excavated. The earth anchor is placed inside the hole, and small is drilled through the Foundation wall from the inside. A steel rod is driven through this hole and is pushed out to the earth anchor in the yard. On the outside, an anchor is fixed on the rod, with a wall plate installed against the inside Foundation wall. This anchor is tightened against the wall, and the tightening process is repeated over time. Once the installation is finished, the hole is filled in, and the removed portion of lawn is restored.
Over time, periodic retightening of this anchor can potentially pull the wall back to its original position- a possibility that merely providing a brace cannot present. Foundation anchors are a cost-effective and fast installation, usually installing in a single day. Installation is possible year-round, and the job is completed with minimal disruption of the yard and with no need to replace the foundation.
Process To Install Wall Anchors
Digging Holes For the Earth Anchors
Before the installation, earth anchor locations will be determined to maximize system effectiveness. When the foundation contractors arrive, their proposal will show the location of each earth anchor in the yard outside your house.
At the beginning of each earth anchor installation, sod is carefully removed from your lawn and placed aside for later. A sheet is laid down to help protect your lawn and landscaping, and an earth anchor hole is made using a power auger.
Preparing The Foundation Wall To Install The Wall Anchors
Once the outside excavation is complete, a small hole is cored through your basement wall. A steel anchor rod is then driven through the wall and surrounding soil, extending out to the buried earth anchor.
This requires only a 1″ diameter hole in your wall.
Attachment Of The Earth Anchor
After securing the end of each anchor rod to its earth anchor, these assemblies are buried in the ground, using soil removed earlier. To resist corrosion damage, each of our earth anchor systems is designed with galvanized steel.
Mounting The Wall Plate
Once the earth anchors have been installed, the service contractors mount a wall plate over each anchor rod end that protrudes from the basement wall.
Screwing a large nut to the threaded end of the anchor rod secures each wall plate and stabilizes the wall as the nut is tightened.
Restoring The Landscape
As part of the cleanup process, the service provider will completely restore the soil grade and the existing landscape ensuring that areas will keep leveled as the soil settle over time.
The service provider will also remove all sod, carefully grooming it with a rake to help it blend in with surrounding grass for a seamless landscaping restoration.
C-Anchors As A Variation Of Wall Anchors
C-Channel Wall Anchors – C-channel anchors are typically used when there is “shearing” at the bottom of the wall. They are placed on the wall approximately every 4-5′, on center. (The term ‘’on center’’ means the distance from the middle of one wall anchor – or any other element – to the middle of the next.)
The average C-channel job takes 1-2 days to complete.
Helical tiebacks are frequently employed when a wall is inclining severely, tilting inward more than an acceptable basement wall bowing of 2″.
It is the most expensive solution after considering the complete wall replacement. But it is also neat and invisible, in comparison with wall anchors.
Best for badly deflected basement walls, helical tie-backs are similar to wall anchors. Both have metal plates on the inside of the basement walls and rods that extend into the ground outside.
But helical tie-backs differ in that they are installed entirely from inside the basement. Holes are drilled at an angle downward. Rods up to 21 feet long are inserted, with the ends attached to the wall plates.
They are placed on the wall approximately every 4-5′, on center (The term ‘’on center’’ means the distance from the middle of one helical tieback – or any other element – to the middle of the next helical tieback).
No exterior soil is modified with the helical tieback solution. Even when it is required to displace soil to install them, this soil is repositioned after the installation is completed.
The average helical tieback job takes about 3-4 days to complete
Helical tiebacks are not exactly the same as the helical piers or push piers that are used to level a foundation, but it is also an underpinning process, so in some way they are similar.
Carbon fiber straps have been utilized with success to toughen basement walls caving in or buckling.
If your wall is buckling 2 inches or more, and exterior excavation for installing wall anchors isn’t a good fit, then your best option is tiebacks. Helical tiebacks are the most expensive option, but they don’t require excavation like anchors do. Tiebacks are installed from inside your basement, through the wall into the yard.
Foundation wall anchors are slightly more effective solutions for bowing foundation walls. Helical anchors consist of a long rod with a corkscrew end that attaches to a wall plate inside of the foundation wall. To install these, large holes are created in the wall (or in the case of block walls, blocks are removed) where the anchors will be installed. A helical anchor is drilled through this hole into the soil. The hole is refilled with concrete, and the wall plates are installed.
Helical anchors are commonly used in the repair of both concrete retaining walls and basement walls, transferring tension loads from the existing foundation to a soil suitable for the load. In order to stabilize bowed basement walls using tiebacks, it’s necessary to relieve the pressure pushing on the walls by removing the soil around them. The helical tiebacks can then be installed into deeper soils that will resist the pressure and allow the walls to be pulled back into alignment. After the tiebacks have been installed and the walls are held in place by the helical piling, the hole is backfilled with gravel, which does not exert as much pressure as soil does when soaked with water. This reduces the force on the walls to help prevent future bowing.
Helical tiebacks are advanced into the soil away from the area placing pressure on the wall, then pull against the interior with a wide plate to spread out the load. This stabilizes the wall by providing enough resistance to negate the outside forces.
Before considering the use of helical tiebacks to fix bowed basement walls, be sure they are suitable for your location and soil conditions. In some cases, tiebacks are not allowed due to property lines, because installation may require extending them 20 feet or more. If there is a neighbor with a basement closer than that, you may not be able to install a tieback system. Also, areas with dense rock are not favorable to helical tiebacks.
Somewhat similarly to anchors, a plate is attached to your basement wall. The steel tieback is driven through the wall and angled downward, deep into the ground. Once the tieback reaches the correct resistance (measured during install by hydraulic gauge), it’s secured to the wall plate to hold the wall in place.
The tieback anchor is installed horizontally through the foundation or retaining wall and driven to an engineered specification and required torque. Then a steel wall bracket is installed on the wall to divert and distribute the pressure.
This system provides a quick and easy installation, it is portable, and can be installed in contained areas.
The weaknesses to these systems are important to remember. The large holes in the block weaken the structure, and when they’re filled in, it’s very difficult to make them watertight, which can lead to flooding later. The soil that these anchors are bracing against is disturbed by the corkscrew’s drilling into it. Heavy equipment must be used during the installation, and the process tends to be very expensive. It’s certainly better than steel beam reinforcement, but this is still not the best option.
Powerbrace Foundation Repair
PowerBrace(TM) is a patented foundation wall repair system that stabilizes failing basement walls and can help to straighten walls over time. This product is a great option when access to the yard outside of the home is not possible but bowing, buckling wall problems need to be solved.
The PowerBrace(TM) is an I-beam system that has several advantages over traditional “old school” systems. This includes its rust-resistant zinc coating and a design that makes it possible not only to stabilize bowing foundation walls but also to straighten these walls over a period of time.
We have already described more in detail the Powerbrace system in this article.
Steel Beam Foundation Reinforcement Against A Bowing Basement Wall
Similar to the Powerbrace system, we have the reinforcement of a buckling wall with steel beams
To install steel beam foundation support, the floor along the foundation walls must be jackhammered where the beams will be placed. The beams are then installed and bolted to the wooden floor joist above. The pressure bearing against the wall is transferred to the wood floor joist, which can lead to damage and buckling in the floor above.
Because the pressure against the wall itself is not addressed, there is still great tension against the walls. This continued pressure can widen the cracks, and over time, even cause the steel beams to bend.
This installation has many other shortcomings. Because the steel beams are straight, rigid supports, they will only touch the foundation wall where it’s bowed outwards the worst- the rest of the wall will not be supported. These beams are also large and awkward, and their installation causes the homeowner to lose several inches of living space while forcing them to remove drywall panels for the installation. Finally, the installation merely braces the walls, whereas other foundation repair methods can provide a way for homeowners to actually straighten and repair the wall as well.
Basement Wall Straightening Against Bowing
I want to emphasize that the goal with all three of these repair methods is to restore stability to your foundation.
Once your wall is repaired, it will not bow any further. If you want to straighten the basement wall and return it to its original position, this will require wall straightening.
Wall straightening is a different approach to repairing a buckling wall. It requires excavation, so the wall can be pushed back upright and help in place with jacks. Once the wall is fully upright, it will need to be secured with carbon fiber straps, wall anchors or tiebacks. Then, the excavated area can be filled back in with soil.
Let´s see the wall strengthening process in more detail.
This process requires quite a bit of work, with the process beginning in your yard. Before the foundation is excavated, the yard around your foundation must be removed. This includes all landscaping such as gardens, steps, walkways, foliage, and everything else located along the foundation. Then the foundation will be excavated, with the removed soil being laid in mounds around the house. Temporary supports will be put in place as the foundation walls are removed and replaced. When the job is completed, the landscaping and dirt can be returned. A year later, this soil will settle and must be regraded.
Again, this is sometimes the only thing that can be done for a failing foundation. However, this solution is very expensive, invasive, and disruptive when installed. Additionally, the process merely replaces the foundation that failed. If you haven’t taken any measures to address the problem that damaged the foundation in the first place, it’s likely that this foundation will fail, just as the previous one did.
How To Prevent Bowed Basement Walls
With the exception of flooding and a ruse in the water table, hydrostatic pressure in the basement comes because of saturated clay soils in the backfill. It does not happen with sandy soils.
Saturated clay soils in the backfill is what you should prevent in the first place.
This often occurs when gutters are left unattended and rain water spills over them, or downspouts drop right next to the foundation. Also, improper grading—when the backfill slopes back towards the foundation—funneling water to the foundation can cause this saturated backfill situation. As the clay soils in the backfill next to the foundation wall gets wet, the soils expand and push the foundation walls in towards the basement.
Repairing bowed basement walls isn’t a do-it-yourself job, but preventative measures are. As a homeowner, you can prevent basement walls from bowing after the repairs:
- Fix downspouts and gutters to prevent water from pooling near basement walls.
- Create a robust drainage system with catch basins that divert water far away from the house.
- Build a French drain to catch groundwater.
- Grade soil away from the house.
- Replace expansive soils that reside against basement exteriors will quick-draining sand or pebbles.
- Remove heavy items like machinery or hot tubs (unless the weight is well-distributed on a concrete pad).
Should I Buy A House With Bowing Basement Walls?
A bowing basement wall is mostly an issue of clay soils and not of sandy soil. Thereforfe, you should check in the real estate object, a house for example, which type of soil rest underneath.
If you’re considering buying a house with one or more bowing walls, call either an experienced foundation repair contractor, or a structural engineer, and have them perform an inspection. They will be able to tell you what’s wrong, and how it can be fixed. The foundation repair contractor will also be able to give you an estimate of how much it will cost to fix the damage. You can then figure this into your offer.
Remember, bowing walls are a sign of structural damage. Never buy a house with bowing basement walls unless you first have the problem inspected by an experienced professional.