What exactly is a Pier and Beam Foundation in San Antonio?
Homes in San Antonio with pier and beam foundations have a system of perimeter concrete grade beams which support the hefty outer 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.
The two common foundation types for homes in San Antonio Texas are: pier and beam or concrete slab. There are advantages to both types of foundation. What you need to understand is the kind of foundation that your home has so that you adequately sustain your home foundation.
Common Pier and Beam Foundation repair problems
pier and beam foundations in Texas. Often has a variety of issues that affect pier and beam foundations that you should be keenly aware of so that you can be repair your damaged foundation as soon as possible to prevent further damage.
- 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.
Block and BaseThe 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 BeamThe 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.
Crawl SpaceThe 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.
Base AssemblyCan be called Piers, or Pier Stations. Consists of 4 parts:
JoistsUsually 2X8 or 2X10 wood planks that support the sub-floor.
Sub-FloorUsually 1X4 or 1X6 tongue-in-groove or shiplap boards.
Finished FloorUsually oak hardwoods supporting the living area.
Access DoorAllows access to crawl space. Can be located through the exterior veneer, and/or through an interior portion of the floor and sub-floor.
VentsOpenings 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.
House levelingLifting 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.
Encapsulation
Crawl spaces are sealed off from outside moisture using 4 main components:
Pier and BeamThe 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.
Crawl SpaceThe 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.
Base AssemblyCan be called Piers, or Pier Stations. Consists of 4 parts:
- Base
- Concrete unit, solid, usually 16X16X4 inches thick.
- Set 6 inches deep in concrete underlay material.
- Gives larger bearing capacity to blocks.
- Concrete unit, solid, usually 16X16X4 inches thick.
- Block
- 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.
- Concrete unit, hollow or solid, usually 8X8X12 or 8X8X16.
- Termite Shields
- Pre-cut, Galvanized metal sheeting installed on top of the last block, to help prevent termite infestation.
- Pre-cut, Galvanized metal sheeting installed on top of the last block, to help prevent termite infestation.
- Shims
- 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.
- 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.
- 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.
JoistsUsually 2X8 or 2X10 wood planks that support the sub-floor.
Sub-FloorUsually 1X4 or 1X6 tongue-in-groove or shiplap boards.
Finished FloorUsually oak hardwoods supporting the living area.
Access DoorAllows access to crawl space. Can be located through the exterior veneer, and/or through an interior portion of the floor and sub-floor.
VentsOpenings 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.
House levelingLifting 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.
Encapsulation
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.