This type of foundation is in many ways a mixture of the Slab and the Pier and Beam. The difference is that a hole is dug and the slab is poured at the bottom. The exterior footing which is usually concrete or masonry blocks make up the exterior walls of the basement extending upward above grade. This supports the exterior walls of the house and the interior
walls of the basement support the interior, much like the interior piers on a Pier and Beam structure. This type is typically found in northern regions.
This type is a variation of the above Pier & Beam where there is no perimeter footing. Support is provided solely by piers and beams throughout. The exterior siding of the house usually extends all the way to grade. This design is typical of older homes found in the southern United States. Some of which are supported by wooden posts of Cedar or Bois D’Arc, an extremely durable wood, embedded in the soil beneath the structure.
Danger
This pier-only type of foundation can be very dangerous. Do not attempt to level this type of structure yourself. The entire house can shift and part or all of the house can fall all the way to the ground. The structures that rest on wooden piers are especially dangerous. There are reports of accidents resulting in death of workers when leveling this type of foundation.
If you do not have prior experience at restoring failing foundations you should leave this task to an expert. You do not want to risk physical injury, death or irreparable damage to your home.
Now that we have covered the basic Foundation Types we will, in the next section, talk about what causes foundation failure.
Differential movement is the single most significant factor in foundation failure. What this means is there is movement of the soil beneath the foundation. There is more movement in some areas than in others. In some cases it can even be movement in one direction in some areas, and movement in the opposite direction in another area.
Poor workmanship and inferior materials in the building of the foundation can add to the effects, but it is still the movement that is the cause.
If the soil beneath a foundation were totally stable then the foundation could not possibly move.
So the next question becomes: What are the possible causes?
Differential movement in the soil beneath a foundation and gravity are the two forces that generally allow a foundation to move. In some instances, tree roots pushing upward can also be a problem. The following are reasons you might experience foundation failure.
If a soil contains a significant amount of clay it is considered to be an expansive soil. An expansive soil expands as it becomes more moist and it shrinks as it becomes more dry. Expansive soils create differential movement whenever the moisture content of the soil is not consistent throughout.
When this happens the foundation sags in the drier areas. It will also tend to be lifted in areas that become more moist than other areas. This raising force is called “Heaving.”
Differential movement can also be caused by the lateral movement of moisture through the soil. This is most common in houses built on hillsides. After precipitation the flow of water on the surface is clearly visible, but what is not visible for days or even weeks later is the movement of excess moisture in the soil which also flows laterally downhill. This problem can be solved by moisture barriers and drains of various types, the most effective of which is a French Drain. We can help you to find a Landscape Professionalwho will give you a free analysis and cost estimate to repair the problem.
Lateral movement can be caused by the lateral moisture movement, underground pressures or nearby erosion or excavation. Any time excavation is planned, it would be a good idea to check with a professional engineer to insure that lateral movement damage does not occur.
A house near the top of a hill will experience little movement while one built near the base of the hill will experience the most movement.
The moisture differential in the supporting soil is caused by one or more of the following conditions:
· Improper drainage
· Faulty gutter systems
· Plumbing leaks under or near the foundation
· Air conditioning
· Natural under-ground moisture flow
· Trees and shrubbery growing too close to foundation
· Lateral Moisture Movement
Plasticity is defined as the degree to which a material will be permanently deformed when placed under a load. The weight of the foundation and everything that it supports places a direct load on the soil beneath it.
If the soil under your home varies in its Plasticity from one area to another the slab will eventually sag in the areas with the greatest plasticity.
Differential in a soil’s Plasticity is primarily caused by differences in the soil’s makeup. Possible causes are:
· Different soil types
· Organic matter
· Uneven compaction of fill soil before slab was poured
If the soil beneath your house remains completely uniform in makeup and in moisture content and is properly compacted and you do not experience lateral soil movement, it is very unlikely that you will experience foundation problems. As you can see there must be differential of some nature in order for the foundation to fail.
The short answer is yes it can. The catch is that if prevention does not start before the foundation is poured, it is difficult to predict whether or not there will be foundation movement.
If the soil that supports your foundation is not consistent, or not compacted properly, or has a high clay content, you will likely face foundation failure sometime in the future.
If you do experience movement, there are steps you can take to slow or stop the movement before it becomes so severe that repairing it will put a major dent in your budget.
1. Use Soaker Hoses during the dry seasons to insure that the soil around your home does not dry out too much. Soaker hoses should be placed no closer than 18 inches to the perimeter of the foundation. Run water until it starts to build up on the surface of the ground. Beyond this point you could potentially create additional problems if the excess water runs down and under the foundation. This is extremely important, so you might want to invest in a timing device that will cut off the flow of water in the event you forget. You can end up with a lot of water under your foundation if you forget and leave it running overnight.
2. Remove shrubbery that is growing next to the foundation. During hot weather the root system of shrubs can remove enough water from beneath your foundation to cause a significant moisture differential.
3. Flower beds that are adjacent to the foundation should be populated with plants that have minimal water requirements. Beds can also be redesigned with moisture barriers and drainage to move excess water away from the foundation.
4. Trees should not be planted too close to a foundation because the roots, while seeking moisture, can extend to great distances. There are studies that indicate that once a tree’s height exceeds it’s distance from the foundation, it is too close. A single tree can remove tremendous amounts of moisture from the soil and cause a moisture differential. Preventive measures include root barriers and even complete removal of the offending tree. An additional benefit of a root barrier is that it can also act as a moisture barrier if it is constructed of the right material.
5. Proper drainage should be maintained to insure that water is not pooling near the foundation. Improper drainage and pooling will almost guarantee foundation failure if no preventive action is taken. The first step is to figure out what is causing the pooling. If erosion has caused soil to be lost, then soil needs to be added to low areas insuring that excess water is diverted. If changing grade is not feasible there are several types of drains that can be installed to divert excess water. The above problems can be solved by selecting a Landscaping Contractor.
6. Run-off from the roof should be collected by gutters and diverted away from the foundation. A distance of 5 feet should be the minimum. Splash guards should also be used to prevent soil erosion. Gutters should be checked for clogs. Longer spans should be checked for an adequate number of downspouts, and the gutter’s angle should be checked to insure that there is no overflow. You should get estimates from a qualified Gutter Contractor .
7. Any sudden increase in water usage could indicate an under slab leak, which unchecked would surely cause foundation failure. Watch your water bill for any sudden changes. If caught soon enough the leak can be repaired before it causes too much damage.
8. If you suspect that your gray-water (sewer) plumbing might be leaking, you should find a Plumbing Contractor to do a Hydrostatic Leak Test. This type of leak can also cause significant damage if left unattended.
We can help you find professional contractors to solve the above problems, just fill out one simple form. Click Here To Fill Form
There are a number of signs that indicate foundation failure. Below is a list of the different items that you should check, and some guidelines on how to assess the extent of the damage.
1. Cracks above windows and doors
2. Cracks in ceilings
3. Gaps between built-in cabinets and walls
4. Doors that are difficult to open and close
5. Cracks in tile floors or walls
6. Windows that stick and are difficult to open and close
7. Doors that fall open or fall closed
8. Floors that are uneven
1. Gaps under walls, between the wall and the floor
1. Cracks in siding
2. Cracks in foundation
3. Gaps around doors and windows
4. Brick trim being pushed out at corners
5. Chimney pulling away from structure
6. Separation of control joints
The extent of the damage generally mirrors the number and the severity of the signs you observe. If you only see a few signs and they are slight, then your damage is probably slight. For example: If you have a couple of hairline cracks but no problems with windows and doors, your damage is probably slight and may be manageable with preventive measures. On the other hand if you observe most or all of the signs and the gaps are wide, you probably have a major problem and will need a contractor to correct the problem.
One thing to keep in mind is that once damage occurs, it will not disappear without corrective measures. For instance, if you observe cracks in your interior drywall during the summer but they tend to close during the winter when there is more rainfall, rest assured, they will come back as soon as summer rolls around and the soil dries out a bit.
If you have repaired the interior and exterior cracks, you will be faced with the cost of repairing them again. Once foundation failure occurs, repairing it will be necessary in order to stop the movement.
Selecting an engineer who specializes in foundation repair problems is the single best way to get a handle on the actual amount of damage. It is important that the engineer you choose have a background in evaluating foundation problems. Engineers tend to specialize in areas of personal preference.
If you believe you need foundation repair performed you will absolutely need an engineer’s report to make sure that you are aware of everything necessary to correct the problem. This will be invaluable when you interview prospective repair contractors to make sure that all needed work is included. You will also know if the contractor is adding anything that is not necessary, potentially saving yourself a lot of time and money.
We maintain a list of qualified engineers in most areas. We can get you in touch with all you will need. We will insure that their expertise matches your needs. Click Here and we will select up to 4 engineers to compete for your business.
NOTE: In some areas there are scam artists claiming to be “Foundation Consultants” who promise to save you thousands of dollars. They usually require an up-front fee in order to inspect your home.
They will claim that you do not need any foundation work, thereby “saving you thousands of dollars.”
Most of these characters are only interested in lining their own pockets. Beware, locating a professional engineer is your best option when you are seeking a third party to evaluate the extent of your problems. This becomes especially important if you should ever end up in a lawsuit.
In general, repair consists of raising the foundation in areas where it may be sagging. In other circumstances, such as when there is a plumbing leak beneath the slab, the repair consists of fixing the leak and waiting for the soil’s moisture content to stabilize. Until the soil has stabilized it is impossible to know the extent of the damage.
There are several methods of raising the foundation that will be covered in the next section.
All foundation repair should be undertaken only by experienced Foundation Repair Professionals because mistakes could compound the problem and could significantly increase the cost of repair. Special equipment that is generally out of reach of the average
do-it-yourself homeowner will also be required to complete the repairs.
Another benefit of having a qualified foundation company perform your repairs is that you will receive a Lifetime Warranty that can be transferred from owner to owner at no cost, a real benefit if you are selling your home.
Added to the financial risk is the risk of personal injury, especially in the case of Pier & Beam structures-where there is a danger of collapse, serious injury and even death.
We provide a free contractor locator service, we maintain details on many professional foundation repair contractors in most areas. We can quickly find at least three local contractors who would be a good match for your problem. We will pass them your job details so they can compete for your business. There is no better way to get a quality job at a reasonable price.
The method you choose will depend on a number of factors including the extent of damage and the prevailing condition of the soil in your area. In almost all situations repair is accomplished by installing piers of various types under the foundation to raise and support it.
The heavier the structure the more closely the piers must be spaced. Concrete piers for instance, should be placed approximately eight feet apart for single story homes, multi-story homes will require pier placement to be more frequent.
The greatest number of piers tend to be along the perimeter of the foundation because this is where the most failure generally occurs. If the interior area of the foundation is sinking, piers will be necessary there too.
The total number of piers, and where they are placed, will also depend on the extent of failure, weight of the supported structure, condition of the foundation, and the chosen type of pier.
The following are the most common types of piers that are used for foundation repair along with descriptions of their main characteristics.
Holes are dug at intervals along the affected areas of the foundation. If a pier is necessary in an area that is covered by concrete then a hole must be cut thru the concrete.
After the holes are dug, a hydraulic press is used to force the concrete segments into the ground directly beneath the foundation. Each segment is pressed on top of the previous using the entire weight of the foundation to force the lower segments deeper.
Many concrete piers are manufactured with a 5/8 inch hole running the length of the pier so that it can be threaded on rebar, cable, or other material that is rigid enough to prevent lateral shifting. In areas where there is no lateral shifting solid concrete segments work just as well with the added benefit of being stronger.
This process continues until the piers reach bedrock or until the friction between the soil and the surface of the concrete segments becomes so great that the weight of the foundation is no longer sufficient to press them deeper.
This is commonly referred to as the “Point of Absolute Refusal.”
After all piers are pressed to the point of absolute refusal, hydraulic jacks are used to raise the foundation in multiple locations and a concrete cap and steel shims are placed between the top of the pier and the foundation. The jacks are then slowly released allowing the weight of the foundation to rest on multiple piers at the same time, insuring that the weight that each pier supports is only a fraction of the weight that was used to press it into place.
Use of pressed concrete piers is the most popular method of foundation repair and probably accounts for more home foundation repair installations than all other methods combined. It is effective in most scenarios and is the only solution in areas where there is no bedrock or soil dense enough for other methods. It also usually costs less than other repair methods.
There are however, times when other repair methods may be more desirable. We will talk about those shortly but first, lets look at the pros and cons of pressed concrete piers.
1. It is quick, usually 1 to 4 days depending on the number of piers
2. If installed correctly, it is extremely reliable
3. It is installed directly beneath the foundation
4. It is very cost effective
1. Installation can be messy because a large amount of soil must be removed in order to provide working room beneath the foundation. Most contractors provide sheets of plywood or other materials to hold the soil until it needs to be replaced. Any excess can be used in low areas or hauled away.
2. Plants may need to be removed, but most companies will carefully remove them and replace them upon completion.
This method utilizes interlocking steel segments instead of concrete segments. Steel piers will usually reach greater depths than concrete piers because steel is smooth and its diameter is smaller so it does not generate surface friction as quickly as pressed concrete piers. In some instances a ring is attached at the bottom of the first pier that is slightly larger than the piers themselves. This ring cuts a larger opening creating even less surface friction allowing penetration to greater depths.
Steel piers are usually pressed along the outside edge of the foundation and not directly under it like concrete piers. Instead a bracket is attached to the top segment of the pier that reaches under the foundation in order to provide support.
1. Requires less soil removal than concrete piers
2. Can reach greater depths than concrete piers
3. Can be installed in less time than concrete piers
1. Pier is not directly under foundation
2. Steel is corrosive and over time can become weakened
3. Higher cost
This pier type is manufactured with a tip that is similar to a giant screw and is literally screwed into the ground. This pier is the fastest to install and has the least impact on the areas where it is installed.
It is in some ways similar to the pressed steel piers previously mentioned yet has some differences. It uses a bracket like the Steel Pier. It is corrosive because it is also steel. It is also quick to install but it may not reach the depth of pressed steel piers. In many markets, it also appears to be more costly.
This pier type depends solely on the diameter of the large screw tip to support the weight placed upon it. These piers are also manufactured with different numbers of screw segments.
1. Extremely quick installation
2. Minimal impact on area of installation
1. Expensive
2. Not installed directly beneath foundation
3. Subject to corrosion
This pier type is constructed in place. Special equipment is required to drill a hole at an angle beneath the foundation. It makes use of a special device that expands the bottom of the hole, that is how it gets it’s name.
A steel framework is then placed into the hole and it is then poured full of concrete. There is a waiting period while the concrete cures, usually two (2) weeks, before the foundation can be supported.
This pier type requires the greatest amount of soil removal, most of which must be hauled away. The maximum depth of the pier holes is limited and in many instances may not reach deep enough past the affected soil to provide proper support.
Another issue with this method is the fact that the pier must be drilled at an angle so the weight does not rest directly on top of the pier.
This type is sometimes installed before a foundation is poured but care should be taken to insure that the depth is great enough to reach stable soil providing proper support. Otherwise the foundation ends up with a large sinking weight attached to it.
1. Can be installed before the slab is poured
2. Extremely high tensile strength
1. Expensive
2. Extremely long installation times
3. Greatest impact on areas near installation
4. Does not provide support directly beneath the foundation
This method does not require piers. It is only effective for slabs and probably makes the most sense for exterior slabs. It raises the slab by injecting different materials
beneath the slab under high pressure, effectively floating it into place. This works well for areas like driveways, patios and walkways.
It should probably not be used as the primary method of raising a foundation because, if used to fill the void where the soil is very dry and the soil again becomes moist, as it expands the foundation would be forced upward possibly causing extreme damage.
· Extremely fast
· Almost zero impact on surrounding areas
· Can cause severe damage on home foundations
Before starting you should already have obtained an Engineer’s Report that details the extent of the problem and what will be required to correct it.
While all engineers are certified by the state in which they practice, many specialize in different areas. Finding one with foundation experience is a critical first step.
You can use our free engineer locator service that pre-screens engineers in your area to insure that they have foundation experience. We can then get you in touch with several qualified candidates who are best suited for your specific needs. Click Here to find an engineer.
The following details could potentially save you thousands of dollars, so pay attention and try to follow these instructions as closely as possible.
After you have your engineer report you should contact multiple foundation companies for estimates. You will need to get enough estimates to end up with three who pass the criteria in this section. To save time and money you can use our Free Contractor Locator service. We maintain lists of qualified contractors in most areas and we can provide you with up to 4 of the best who offer free estimates and will compete for your business.
You should interview the foundation company’s representative who comes out to give you an estimate. First allow him to finish the estimate paying careful attention to everything he does.
The estimator should first ask about the problems you are having. He should then inspect the structure inside and out for signs of damage. He should also draw a scale diagram of the perimeter of the structure. This is to allow him to take elevation measurements and record them on the diagram. The elevation readings on the diagram should be spaced no farther apart than 10 feet.
The most common type of instrument for foundation elevation readings is called a CompuLevel or a ZipLevel. It allows the estimator to set a benchmark and take elevation readings that are +/- one tenth of an inch relative to the benchmark. If your estimator does not use this, or a similar device, it is unlikely that he can fully evaluate the extent of your damage.
After the estimator finishes with his inspection, you should ask as many of the following questions as you feel are necessary. Make note of all questions that he does not seem comfortable answering. While he should be able to easily answer most of the questions, it is possible that there are some that he may be unfamiliar with.
Ok, here is the list of questions with best answers.
· What are the city building codes in my area and will your company secure a city Building Permit for the project? Most cities will require a building permit. NOTE: some cities may require extensive reworking of Pier & Beam structures.
· Will your company perform plumbing tests before repair work begins? This is generally a good idea.
· Will your company performs plumbing tests after repair work is complete? Yes, the repair process can cause plumbing leaks.
· Will your company provide an engineer’s report after repairs are complete?It is good if they do but you should have the engineer you retained prior to the repair to re-inspect the slab.
· How long has your company been In business? 5+ years.
· How much foundation experience does the crew that will be doing my work have? This is just as, if not more, important as the previous question.
· What are your payment options? For your information.
· How many crews do you have in the field? For your information.
· Can I meet my crew on their current location, if not how about an alternate crew? You may or may not want to do this but it may be useful to see the estimator’s reaction.
· What is the next available date? Most established companies will be scheduled out anywhere from a couple of weeks to a couple of months. During the busy season it can be even longer.
· What is your company’s dispute resolution process? Arbitration usually works out better than lawyers. Both you and the contractor should be bound by the arbitration.
· Do you have a copy of your warranty for me to inspect? Yes, inspect carefully for loopholes and extra fees. There should be none.
· Do you have a copy of your Contractor’s Liability Insurance that I can inspect? Yes, you can follow up to make sure it is still in force.
· Do you have a copy of your Workmans Comp Insurance that I can inspect? Generally Yes, some states require this and some do not.
· Does your company have all required licenses, city and state? Yes.
· Can you provide a list of references I can check out? Yes, at least 3.
· Can you provide a reference from a warranty customer? Yes.
· Do you have a job in progress that I can visit? Yes.
· Are there extra charges for plumbing tests, building permits, and engineer reports? This is something you must consider as it relates to the total cost. If you are providing any of these you should ask for the cost to be removed from your estimate total. It is a good idea to retain the engineer and plumber you contracted with prior to repair, to test the plumbing and inspect the job after it is finished.
You should have estimates from at least three (3) companies to outline the corrective measures needed. It is from these companies that you will choose your Foundation Contractor.
Do not mention the engineer’s report up front. Let all three companies give you their estimate and carefully look them over before making a decision. You want to see which ones most closely match the engineer’s estimate. This will give you a clue as to their competence.
First look at the estimated cost for each estimate. Check out the highest and lowest, paying careful attention to why they are higher or lower. Different factors affecting the cost could be; different pier type, cost per pier, number of piers or additional items and services.
If any of the estimates are significantly lower than the others you should figure out why. Usually you will want to discard an estimate that is extremely low.
What you are looking for is an estimate with a price that is somewhere in the middle, and is also similar to your engineer’s report.
There is room for disagreement on what it takes to repair a foundation. Most companies will usually go along with your engineer’s report and will be willing to install whatever is detailed in his specification.
Because of population growth and the boom in the housing industry over the past 30 years, foundation repair is a high growth industry. Many less than honest individuals who are looking for the quick buck, are becoming involved.
If you are unfortunate enough to contract with the wrong company, you will probably get a sub-standard job and when you call to exercise your Foundation Warranty you may find that you cannot locate the company because they have disappeared.
They probably did not really disappear. They are very likely doing business under a different name with a different phone number, hiding from all of the warranty calls they would surely have received.
You want to make sure that you do not do business with one of these companies. One way to spot them is that they will offer you an extremely low price.
Others may offer some gimmick like “double piers” at a low price that seems “too good to be true.” When you need a pier adjustment you will probably find that there is a per pier adjustment fee hidden in their warranty. Double piers will probably translate into double adjustment fees.
One thing you should always remember, “If it seems too good to be true then it probably is.”
Another ploy is to estimate a number of piers that is less than actually needed in order to get you to commit to having them do the repair. This allows them to present an estimate with the lowest price. Their warranty will probably state that it is invalid if any other company works on the foundation. They then have you hooked.
You will be forced to use them for the rest of the work if you want to maintain your warranty. Those who conduct business in this manner will probably not honor their warranty anyway.
If you are selling your home the buyer’s inspector will probably find the damage that was not repaired and you will need to have it all repaired in order to sell your home.
Many states enforce severe penalties if someone sells a home and withholds damage information from the buyer.
Again on warranties, insist that you be given a sample copy of the warranty you will receive before any work begins. You should examine it carefully to make absolutely sure that there are no exclusions that would render it useless.
You might want to let us help, it is our business to contact local contractors on your behalf and pre-qualify them with our Free Contractor Locator Service. We have lists of contractors in most areas of the US that are qualified to do your work and will do it for a fair price. We pre-screen the contractors that we recommend. We also seek feedback from customers and if a contractor gets too much negative feedback we will cease to recommend them.
We can get you in contact with local professional contractors in all areas of home services. Click Here and fill out one form and we will send up to four (4) professional contractors, per area of need, who will give you a call and compete for your business.
Thank you for reading this report. It is our sincere hope that we have helped you understand what goes on behind the scenes in the foundation repair business. With the knowledge you have gained you should be well on your way to getting the quality job you deserve at a price that is reasonable.
You can use the following links if you want to get in contact with local contractors in our list or if you want to send this report to a friend.
