The two common foundation types for homes in Texas are: pier and beam or concrete slab. There are distinct advantages to both types of foundation. It’s important to understand the type of foundation that your home has so that it can be properly maintained and repaired.
What is a Pier and Beam Foundation?
Homes with pier and beam foundations have a system of perimeter concrete grade beams which support the heavier exterior walls. Unlike slab foundations which totally sit on the ground, the interior portion of pier and beam foundations are supported by a series of concrete blocks. This creates a cavity, or crawl space under the structure, usually 14 – 24 inches tall. When interior portions settle, it is much easier to crawl underneath and shim the blocks.
Pier and Beam Foundation Issues
Well-crafted pier and beam foundations tend to have fewer overall issues and less expensive repairs than other foundations. However, there are certain issues that affect pier and beam foundations that home owners should be aware of so that they can be repaired quickly.
- Moisture: If there is insufficient drainage under the house, water can accumulate after heavy rains and cause mold or sinking.
- Rotting wood: compromised wood pieces need to be replaced
- Sagging: If the beams were not properly spaced during construction, the weight of the house becomes too heavy and leads to sagging.
If you notice sagging floors, gaps between the floor and interior walls, cracks in the drywall, or unleveled door frames, it is important to have a pier and beam foundation expert inspect your home and discuss your repair options.
Pier and Beam Foundation Repair Professionals
Over the years, as fewer and fewer companies repair the Pier and Beam type of foundation, a lot of the expertise went away with the craftsmen who specialized in this system. Consequently, some of the terminology has also been lost, or confused with some of the newer method’s terms.
Vulcan Foundation Repair uses the “Old Fashioned” way to repair Pier and Beam foundations, and that’s why our repairs tend to last 3 – 4 times longer than lesser methods. This translates into saving thousands of dollars not having to re-level more frequently, plus the headaches and costs of repeated cosmetic repairs over the long run.
The following is a list of the terminology. We hope it proves useful as you gather estimates, and look for the most knowledgeable and experienced craftsmen to repair your foundation the “right way”.
Block and Base
The entire structure is raised, usually about 14 – 24 inches above the soil, and is totally supported by concrete blocks, called Base Assemblies, Piers, or Pier Stations. On top of the Base Assemblies are treated 4X6 or 6X6 beams, (or Sills), which support the sub floor and main floor. You can look under the house and see all the way to the other side, if lattice work, landscaping, and height off the ground permit.
Pier and Beam
The middle of the structure is supported like a Block and Base, but the perimeter is supported by a concrete Grade Beam, usually 20 – 24 inches deep, and about 12 inches wide. The exterior veneer, usually brick or stucco, rests on this beam, as does the perimeter sill.
In older homes, there are usually vents in the exterior veneer to allow air flow under the structure, to attempt keeping the soil moisture content low.
In newer homes, moisture control systems like Encapsulation Plus* may have been installed, to further reduce the amount of moisture in the soil.
The area under the structure between the soil and the bottom of the beams or sills, (usually 18 inches or greater). Allows workers to service utilities located under the structure, and easier access to Base Assemblies should re-leveling ever be needed.
Can be called Piers, or Pier Stations. Consists of 4 parts:
- Concrete unit, solid, usually 16X16X4 inches thick.
- Set 6 inches deep in concrete underlay material.
- Gives larger bearing capacity to blocks.
- Concrete unit, hollow or solid, usually 8X8X12 or 8X8X16.
- Set on top of bases. Can be connected to each other with rebar inserts, and filled with concrete grouting.
- Termite Shields
- Pre-cut, Galvanized metal sheeting installed on top of the last block, to help prevent termite infestation.
- Preferably Steel (3″ X 5″ sections), used to complete the leveling process. Sometimes wood shingles, old pieces of wood, broken concrete blocks, or other miscellaneous material laying around has been used, and should be replaced with steel shims.
Can be called Sills, Girders or Trusses.
- Usually Treated 4X6 or 6X6 wood material, in 16 foot lengths.
- Girders usually refer to Steel ‘I’ Beams.
- Trusses are pre-made supports for sub-floors. They are almost exclusively used in new construction, to replace standard 6×6 Beams.
- Beams are placed on top of the Base Assemblies, and support the wooden floor joists.
Same material as original Beams or Sills, but added later to provide extra support when needed, evidenced by dishes or other items that rattle, or “Shake”, when walking across a floor area. Reinforces main original beams and greatly enhances load bearing capacities and foundation life.
Usually 2X8 or 2X10 wood planks that support the sub-floor.
Usually 1X4 or 1X6 tongue-in-groove or shiplap boards.
Usually oak hardwoods supporting the living area.
Allows access to crawl space. Can be located through the exterior veneer, and/or through an interior portion of the floor and sub-floor.
Openings in the exterior veneer to allow air flow under the structure, attempting to keep the soil moisture content low, preventing standing water, and settlement of the Base Assemblies.
Encapsulation Plus: A Vulcan Exclusive
Ultimate system of moisture control, utilizing the most modern techniques, and representing the latest studies in maximizing foundation longevity. Encapsulation Plus was designed to minimize mold and insect problems, reduce energy costs, and increase the life of the foundation components.
Crawl spaces are sealed off from outside moisture using 4 main components:
- Landscaping corrections including French and Yard Drain Systems, and gutters to control rain water.
- Insect prevention by grading soil under structure to prevent standing water areas, and by installing termite shields.
- Soil and wall areas are sealed using specialized encapsulation materials and sealants to control ground water.
- De-humidifiers are installed to further reduce moisture content, which can prevent mold and mildew, reduce heating and cooling costs, protect the wood members of the foundation, and create a safe work area for service personnel.
Lifting the entire structure and adding additional blocks, usually in 8 inch increments. Enlarging the crawl space greatly enhances foundation life by improving air flow, keeping the soil dry. We are then able to add and grade soil to create a “crown” effect in the middle of the structure, so that any water penetration flows out, away from the foundation system, instead of inward to the middle. Raising the structure higher off the ground also helps to prevent termite infestation.
external link raisedfloorliving.com