One of the most intimidating repairs to new house flippers and rehabbers are foundation problems. Foundation repairs can be expensive, but if you know what you issues to look for and know the possible solutions you can use foundation problems as an advantage to negotiate a better deal.
In this article we will discuss most common foundation problems and issues you will likely encounter when inspecting rehab properties and discuss the potential repairs and solutions to re-stabilize the home and make it appealing to new home buyers.
Common Foundation Issues
Foundation problems and issues can be classified into 3 categories:
Settling and heaving is caused by vertical movement upward or downward of the soils beneath the home's foundation. If all of the soil beneath a foundation shrinks uniformly or swells uniformly it is unlikely to cause a problem. However, when only a portion of the foundation heaves or settles, differential movement causes cracks in floors, walls and ceilings.
Most differential movement is caused by differences in soil moisture.
Heaving
Heaving occurs when a foundation or a concrete slab is forced upward by the expansion of soils beneath the foundation. A dramatic gain in moisture from wet weather, poor drainage, or even plumbing leaks can cause the soils to expand and 'heave' the slab and foundation vertically.
Settling
Settling occurs when a foundation or concrete slab falls downward due to the contraction of soils beneath the foundation. Settling is often caused by a loss of moisture that causes the supporting soils to shrink and the foundation to fall vertically.
Here are the most common causes of foundation heaving & settling:
Sloping Lawns – Sloping lawn can pile tons of heavy soil on your foundation, making your interior basement walls bow inward.
Wet Soils – Something as simple as the weather can create bowing basement walls. When the soil around your basement walls becomes saturated with water, either from general rainfall or runoff from clogged gutters, it becomes very heavy. This is turn introduces more stress on the basement walls, causing them to bow.
Leaky Pipes – Like with rainwater, plumbing leaks can saturate the soil around your foundation with water and cause wall bowing.
Trees – Roots from trees planted too close to your home will press against your basement walls and cause bowing.
Heaving and settling is often an issue in areas with varying soil conditions. For example one half of the foundation my sit upon expansive clay and the other half may bear on select fill or rock. Throughout the seasons the soils will move, expand and contract at different rates causing differential movement which may cause damage to the foundation & structure.
Signs of Vertical Movement
As you are walking through and inspecting your prospective rehab properties look for signs of vertical movement:
Cracks in Slabs or Uneven Slabs
Sagging or Uneven Floors
Cracks in Masonry Facade
Cracks in Drywall
Doors that Stick or Don't Open and Close Properly
Gaps around Window Frames or Exterior Doors
Counter Tops Separating from the Wall
Foundation Repair Solutions for Vertical Movement
There are a number of ways to repair foundation settling and heaving issues:
Step #1 Fix Water Issues & Exterior Drainage
Once you've resolved the water issues you need to raise the settled foundation back into place using piers or mudjacking.
Fix gutters and downspouts to ensure rain water is directed away from the foundation
Fix exterior slope so water flows away from your foundation
Install an exterior french drain around the foundation perimeter
Step #2 Fix the Foundation (Piers/Mudjacking/Foam Repairs)
Steel Piers - Steel piers are hydraulically driven into the ground below your foundation footing. Steep piers generally take less time and disturb less landscape than concrete piers. Steel piers can be installed either from the exterior or on the interior of the property.
Helical Piers - Helical piers are screwed into the ground below the foundation footing like a giant screw.
Concrete Piers - Concrete piers are piers that are dug-out under the existing foundation footing and poured in-place. Concrete piers require larger footings, more digging and disturb more landscape than steel piers or helical piers.
Mudjacking - Mudjacking is used to lift concrete slabs by drilling holes in the slab and pumping a slurry of mud (water, soil, sand & cement) under the slab to lift the slab back into place.
High-Density Polyurethane Foam - Similar to mudjacking, polyurethane foam can be injected underneath the slab to lift the slab back in place. Foam is quickly becoming a more popular solution than mudjacking because of it's affordability and speed of installation.
Exterior Pier Installations
Steel piers, helical piers or concrete piers can be installed from the exterior of the property to raise the foundation.
Exterior Pier Installations are generally best used when you have a finished basement that you do not want to disturb. Exterior Piers are generally more expensive than Interior Pier Installations due to the added excavation.
Step 1 - Raising a Foundation with Exterior Steel Piers
Step 2 - Raising a Foundation with Exterior Steel Piers
Step 3 - Raising Foundation with Exterior Steel Piers
Interior Pier Installations
Foundation piers can also be installed from the interior of the property.
The process of an Interior Pier Installation requires the interior slab on grade to be cut-out every 6 to 10ft (according to the Structural Engineer's recommendation) in order for the piers to be installed below the footing.
Interior Pier Installations are best suited for unfinished basements that won't be affected by the installation.
Step 1 - Raising a Foundation with Interior Steel Piers
Step 2 - Raising a Foundation with Interior Steel Piers
Bowing Walls & Cracks (Horizontal Movement)
As discussed above, soils can expand vertically causing vertical heaving, but they can also expand horizontally causing pressure on your walls which can cause your foundation walls to bow, lean or crack. This horizontal expansion again is caused by excessive moisture in expansive soils.
Sloping Lawns – Sloping lawn can pile tons of heavy soil on your foundation, making your interior basement walls bow inward.
Patios and Driveways – Brick and concrete are extremely heavy, and if placed near your basement walls, can cause them to bow.
Rainy Weather – Something as simple as the weather can create bowing basement walls. When the soil around your basement walls becomes saturated with water, either from general rainfall or runoff from clogged gutters, it becomes very heavy. This is turn introduces more stress on the basement walls, causing them to bow.
Leaky Pipes – Like with rainwater, plumbing leaks can saturate the soil around your foundation with water and cause wall bowing.
Trees – Roots from trees planted too close to your home will press against your basement walls and cause bowing.
Settling and heaving is caused by vertical movement upward or downward of the soils beneath the home's foundation. If all of the soil beneath a foundation shrinks uniformly or swells uniformly it is unlikely to cause a problem. However, when only a portion of the foundation heaves or settles, differential movement causes cracks in floors, walls and ceilings.
Signs of Horizontal Movement
As you are walking through and inspecting your prospective rehab properties look for signs of vertical movement:
Bowing Foundation Walls
Cracks in Foundation Walls
Sagging or Uneven Floors
Cracks in Drywall
Doors that Stick or Don't Open and Close Properly
Gaps around Window Frames or Exterior Doors
Counter Tops Separating from the Wall
Foundation Repair Solutions for Horizontal Movement
There are a number of ways to repair foundation settling and heaving issues:
Step #1 Fix Water Issues & Exterior Drainage
As mentioned previously, most foundation issues are caused by excessive moisture in the soils around the foundation, so the first issue that needs to be repaired is the water drainage around the property.
Fix gutters and downspouts to ensure rain water is directed away from the foundation
Fix exterior slope so water flows away from your foundation
Install an exterior french drain around the foundation perimeter
Step #2: Stabilize & Support the Foundation Walls
As mentioned previously, most foundation issues are caused by excessive moisture in the soils around the foundation, so the first issue that needs to be repaired is the water drainage around the property.
Steel I-Beams
Steel I-beams can be installed every 5 to 6 feet along the interior of the foundation wall and attached to the existing floor framing to stabilize the wall and prevent further bowing.
4" I-Beam Restraint & Crack Injection
4" I-Beam Restraint Installation
4" I-Beam Restraint Installation
Carbon Fiber Beams
Similar to steel i-beams, carbon fiber strips can be laminated to the foundation wall to stabilize and support the wall and prevent further bowing. Carbon fiber strips provide the strength of an I-beam, but can be used in narrow spaces that don't have the space for a 4 to 6" I-beam.
Carbon Fiber Crack Repair
Crack Repairs (crack injections)
Foundation cracks can be stabilized by injecting the cracks with epoxy or polyurethane. Epoxy injections are used for structural crack repairs where polyurethane injections are used more for waterproofing solutions.
Epoxy or Polyurethane Injections
Repair Solutions for Water Issues
Water intrusion is another common problem in basement foundations. Water intrusion can cause a number of issues in your basement including dampness, flooding, wood & drywall rot, and mold.
Step #1 Fix Water Issues & Exterior Drainage
Again, the first issue that needs to be addressed is the water drainage around the property.
Fix gutters and downspouts to ensure rain water is directed away from the foundation
Fix exterior slope so water flows away from your foundation
Install an exterior french drain around the foundation perimeter
Step #2: Waterproofing & Drainage
Once the water issues have been resolved you have several different options waterproofing your basement:
Interior Drain Tile System
Exterior French Drain or Curtain Drain
Waterproofing Block Foundations - Interior Drain Tile System
French Drain - Removing Water with Bad Grading
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