Monday, January 31, 2011

Foundation Repair

Foundation repair is the most complicated and the most expensive type of repair your home will ever need. This is the reason why so many people go to school to get training specifically to become a foundation repair contractor. Foundation repair is not something most people like to think about. Foundation problems can be a stressful, potentially costly endeavor, filled with uncertainty, particularly if not done professionally. Foundation Repair is needed when your foundation begins to settle. This can be caused by building on expansive clay, compressible or improperly compacted fill soils, or improper maintenance around foundations. Mother Nature plays a big part in this also depending on the state you live in and how cold your winters can get.

Foundation repairs are usually quite expensive, but are an essential home improvement. Foundation repairs are often difficult and expensive, so its important to build the foundation correctly the first time. The Build A Better Home program from APA- The Engineered Wood Association is designed to provide builders and homeowners with the construction guidelines they need to protect their homes against damaging moisture infiltration. Foundation repairs aren't easily performed, so breathe deep, sit back and hope for the best. When your choices are few and far between, you need to find the best contractor for the job. The lowest price is not always the best way to go and if you choose to make your final decision on just that fact, be prepared to be disappointed most of the time.

Cracks that are buckling, bowing, sinking and other defects are commonly caused by the foundation settling, unstable or shifting soil, environmental conditions or even poor landscaping design. When left untreated, these seemingly minor problems can become a major headache and lead to serious structural damage. The earlier you catch this problem and try to fix it the better your chances of it not costing a fortune.

Foundation repair cant be ignored. The traditional answer to foundation repair has been to erect piers to jack up the foundation and raise it off the expansive clay soil. Piers have several distinct disadvantages and drawbacks. Foundation repair can be expensive and tricky. You'll want to shop around and get several bids from several different contractors as well as have a look at their experience in such matters. Foundation repair can be the most expensive repair that you will make to a property. One of the saddest things I've heard in the investment community are the stories of investors who have purchased a property, rehabbed it, and put it on the market only to have the buyer's inspector tell them there was a problem with the foundation.

Cracks and other damage can look unattractive, reduce the overall value of your home and lead to more serious structural problems. Steps can be taken to fix foundations to maintain the quality and value of most homes. Cracks usually develop in the floors and grade beams of buildings having an abnormal degree of differential settlement. The cracks in concrete are normal and could be a symptom of differential settlement and not the problem.

Foundation repair is critical to address as soon as you suspect a problem. For starters, the sooner you fix a failing foundation, the less damage it will cause. My best advice any professional contractor can give a homeowner in need of foundation repair is to remedy the problem as soon as possible before it gets worse and leads to several costly other repairs.

Monday, September 13, 2010

How does concrete crack?

Concrete is a building material made from a mixture of Portland cement, sand and water. It is used to construct floors, foundations and walkways in a variety of commercial and residential structures. Though this material is known for its strength and durability, concrete suffers damage because of high levels of abuse or improper installation. Concrete typically shows damage in the form of cracks, which can range from light surface fractures to holes that are large enough to make a structure unusable.

Tuesday, August 17, 2010

Inspecting a Foundation

Whatever their construction, (concrete, brick, concrete blocks, etc.), foundation walls crack because of lateral force, settling, heaving or uneven loads (more weight than designed on a specific section of the foundation), of the foundation walls. Natural forces such as earth quakes can also be a contributor in earthquake regions.
To begin your inspection, use a pad and pencil while observing the exterior foundation. Make notes of cracks and their locations. When inside the lower level, you will want to try to locate them on the inside. If the crack goes entirely through the foundation it may be a red flag. Small hair-line cracks that do not go through the foundation wall are common and nothing to worry about; they may have been caused by shrinkage of the concrete or mortar joints.
A found crack sometimes has a similar type crack on an opposite wall of the foundation. Similar cracks on opposite walls may have the same cause, with the exception of horizontal cracking caused by a lateral force.
Types of Cracking
Vertical and 45 degree cracking is usually caused by settlement and heaving. Horizontal cracking is commonly caused by side pressure on the foundation, such as hydrostatic pressure (a lateral force). Surface cracks that do not go entirely through the wall and with no signs of displacement are not normally a structural defect. Isolated vertical cracks that do not extend to the lower edge of the foundation wall are usually shrinkage cracks. They are caused by the concrete shrinking during curing.
Causes of Horizontal Cracking
The foundation should act as a retaining wall, resisting lateral pressure of the soil on the outside of the basement or crawl space. If the foundation does not provide enough lateral support, the walls will deflect inward and create horizontal cracking. Some of the causes are foundation walls that are too thin or do not have, (or not enough), reinforcement, such as rebar in the concrete foundation, backfilling the foundation too soon before the foundation has a chance to fully cure, or during back filling if big stones or hard frozen chunks of ground were dumped against the foundation.
Causes of Heaving Foundations
Heaving cracks in foundations made out of brick, blocks, or stones,(not concrete), will generally have cracking in the form of a step, called "step cracking". Step cracking usually follows the mortar joints in these materials.
In concrete foundations, cracks from heaving are usually vertical and are wider at the top of the crack than at the base.
Some areas of the country have expansive soils, which increase in size when they absorb water, causing heaving cracks. Moisture added to dry expansive soils, say from a sudden down pour, will drastically change the volume of the soil and cause serious heaving problems as well as structural damage in some cases. When the expansive soil dries, the shrinkage can also cause a pulling effect on the foundation. The method of prevention is to maintain the soil moisture content, by keeping the soil as dry as possible along the foundation. This can be achieved by proper grading around the perimeter.
Causes of Foundation Settlement
Settling of the soil under the foundation is usually the cause of settlement cracks in the foundation walls. Cracks caused by settling resemble cracks caused by heaving, except the crack is wider at the lower end of the crack.
If a crack is active the crack may still be moving, (getting bigger, etc.) To identify an active crack, it will have sharp edges, clean inside of the crack and sometimes with bits of concrete still in the crack. Old cracks will have dust, dirt, paint and insect parts in the crack.
To determine the severity of a crack or its cause, it may need to be evaluated by a geotechnical engineer. Large cracks 3/8" wide should be carefully examined. Cracks can be measured by the engineer, to determine if it is moving or if it is stabile. Many times Home Inspectors call on the services of an engineer, to be sure the foundation is sound. As a past Home Inspector, I have been surprised several times to find questionable cracks were sound without a concern. I was always glad it was verified for the sake of the buyer or yourself in your case.
What to look for inside the house structure:
Doors and windows that are stuck and misalignment (gaps)
Foundation settlement can cause doors and windows to be come misaligned. This can be seen when observing the edges around the windows or doors, where they close. Look for gaps larger on one side than the other. This can help determine where the settling is occurring.
Cracks in the walls
Settlement will usually cause wall cracking. Settlement cracks are wider on one end than the other. Let it be known wall cracking can also be caused by the house expanding and contracting through its seasons. If there is no evidence of foundation defects and there is wall cracking, it, more than likely, is caused by the latter.
Sloping or tilting floors.
I have learned during my home inspection career that most people will not notice sloping less than 1/8" slope per foot. 3/16"slope per foot is noticeable to most people. A family living in an older home for a long time might not notice sloping even if severe. We tend to adjust to gradual sloping over time.
If there is doubt, use a level to determine if the floor is level. Floor elevations should be recorded for future reference in the inspection.
Unless the sloping is substantial or extensive remodeling is planned, the best repair would be to stabilize the foundation. Extensive re-leveling in an older home may cause more than expected damage to the interior walls, ceilings, doors, windows and cabinetry.
If the home has been stabilized and future movement is unlikely, buyers will often accept the uneven floors.

Monday, September 14, 2009

SUBSIDENCE
DEFINITION: Subsidence - The sinking down of land resulting from natural shifts or human activity, frequently causing structural damage to buildings in the form of Foundation Cracks, Concrete Cracking, Doors and Windows Sticking, Wall cracks, and other problems.
STOP the damaging effects of foundation settling! A shifting foundation may result in structural damage to your home and a loss of your investment.
WE HAVE THE SOLUTION TO YOUR FOUNDATION PROBLEMS
Building Foundation Repair
Our foundation support systems utilize end-bearing helical anchors, installed per engineered specifications. This innovative approach offers a superior and cost-effective alternative to other stabilization methods.
The concept is founded on the principle of turning a screw anchor into stable soils, then attaching adjustable brackets to the base of your foundation thereby transferring the weight of your home to the screw anchors. In the process, foundations, walls, and floors are repositioned, and restrained from further movement.
Screw anchors can be used in a myriad of applications from the underpinning of structures; tie-backs for lateral wall or slope support; to alleviating soil subsidence problems.
Foundation Lifting and Leveling
Along with limited access capability, our method eliminates much of the unnecessary damage created by other forms of underpinning by producing far less disruption and distress during the installation process.
Chris M. Cobb Construction Services, Inc. has been involved in numerous, successful projects throughout southern California. Should you find yourself dealing with a foundation problem, please contact us. We're confident you will be impressed with our systematic and organized approach.
We have years of experience correcting problems throughout Southern California (Orange County, Riverside County, Los Angeles area, Ventura County, and San Bernardino County) such as concrete cracking, foundation and drywall cracking, windows and doors sticking, and much more.