Foundation Repair Terminology
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 having to re-level more frequently, plus the headaches and costs of repeated cosmetic repairs over the long run.
Over the years, as fewer and fewer companies repair the Pier and Beam type of foundations, a lot of the expertise retired with the men who specialized in this system. Consequently, some of the terminology has also been lost, or confused with some of the newer method's terms.
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".
Types of Foundations
Slab-on-Grade
Forms are placed, rebar laid, and moisture barriers are installed directly on top of the soil. Then concrete is poured, usually 4 inches thick. The perimeter and interior load bearing walls are supported by grade beams, approximately 18 inches deep. There is no crawl space, and the water table is too high in Houston for basements.
Block and Base:
The entire structure is raised, usually about 14 - 30 inches above the soil, and is totally supported by concrete blocks, called Base Assemblies, Piers, or Pier Stations. On top of the Base Assemblies, 4" X 6", or 6" X 6" wood beams are installed, 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, landscaping, and the 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. This perimeter beam supports the brick or stucco veneer, and stiffens the structure's load bearing capacity. Vents are usually added in the exterior veneer to allow good air flow, keeping the soil moisture content low.
In newer homes, moisture control systems like Encapsulation Plus may have been installed, which represent the newest technology for reducing the moisture content of the soil.
Foundation Components
Crawl Space:
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.
Base Assembly: Can be called Piers, or Pier Stations. Consists of 4 parts:
1) |
Bases
- Concrete unit, solid, usually 16" X 16" X 4" thick.
- Set 6 inches deep in concrete underlay material.
- Provides larger load bearing capacity to blocks.
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2) |
Block
- Concrete unit, hollow or solid, usually 8" X 8" X 12" or 8" X 8" X 16".
- Set on top of bases. Can be connected to each other with rebar inserts, and filled with concrete grouting.
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3) |
Termite Shields
- Pre-cut, galvanized metal sheeting installed directly on top of the highest block, to help prevent termite infestation.
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4) |
Shims
- Preferably steel (3" X 5" sections), used to complete and fine tune the leveling process.
- Other shim materials common in the past (but not recommended)- wood shingles, old wood boards, broken concrete blocks, rocks, logs or other miscellaneous material.
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Beams: Can be called Sills, Girders, or Trusses
- Usually Treated 4" X 6" or 6" X 6" wood material, in 16 foot lengths.
- Girders usually refer to Steel 'I' Beams.
- Trusses are pre-made supports for sub-floors, and are almost exclusively used in new construction, replacing standard 6" X 6" treated wood beams.
- Beams are placed on top of the Base Assemblies, and support the wooden floor joists. |
Shaker Beams:
Same material as original Beams or Sills, but added later to provide extra support when needed. One of the evidences that shaker beams are needed is when dishes or other glassware rattle, or 'shake' when walking across the floor. Reinforces main original beams and greatly enhances load bearing capacities and foundation life.
Joists:
Usually 2" X 8" or 2" X 10" wood planks, set on end, that support the sub-floor.
Sub-Floor:
Usually 1" X 4" or 1" X 6" tongue-in-groove or shiplap boards.
Finished Floor:
Usually oak hardwoods supporting the living area.
Access Door:
Allows access to crawl space. Can be located through the exterior veneer, and/or through an interior portion of the floor and sub-floor.
Vents:
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 -
Encapsulation Plus is the ultimate moisture control system available. The technology behind it represents the latest research, and utilizes the most modern techniques in maximizing foundation longevity.
By keeping the soil under a structure dry, the foundation components are prevented from settling, reducing repeated foundation leveling costs. The ROI, Return On Investment, far outweighs the installation and maintenance costs over a relatively short time span. Other benefits include minimizing mold and insect problems, reducing energy costs, and ease of access by other services personnel.
The 4 main components of Encapsulation Plus:
1) |
Landscaping Corrections - including proper grading of the soil, French and Yard Drain Solutions, and gutters to control excessive rain water. |
2) |
Insect Prevention - Debris removal and soil grading under the structure will help prevent standing water, and to eliminate insect breeding areas. Installing Termite Shields. |
3) |
Encapsulation -
Insulating and sealing off all walls, vents and sub-floors.
Installing special moisture barriers over the soil and walls.
Bonding all agents together. |
4) |
Moisture Removal - De-humidifiers are installed to further reduce moisture content, which can help 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.
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Support Systems For Perimeter Grade Beams
Deep Drilled Bell Bottom Piers
The most important step in this method is the initial soil testing and design by a Geotechnical Engineer. Once the pier size and depth are determined, workers drill 9" to 12" shafts to depths of up to 12 feet deep. They then bell out the bottom of the shaft to circumferences of 20" to 36" wide. Steel rebar is placed in the shaft and 3000 PSI concrete is poured. After a 2 - 4 week concrete curing period, workers return to raise and level the grade beams.
Pressed Pilings:
Workers dig under the perimeter grade beams, and using the weight of the structure, press 6" or 8" pre-made concrete cylinders into the soil. Depending on the type soil in the area, and the load to be supported, some depths can exceed 25 feet.
The most important component of this system is the connection method of the concrete cylinders. The straighter the pilings are driven into the ground, the better the soil-friction they will develop. Properly connected and tensioned pilings, driven to depth-of-refusal, have less than 1/2 of 1% maintenance requirement over the first 10 years.
Special Services
House Raising:
Block and Base houses are raised by installing 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 grade additional soil, creating a higher area in the center of the structure, helping prevent water from collecting underneath. Raising the structure higher off the ground also helps to prevent termite infestation.
Crowned Floors:
Wood floors in a heaved or bubbled condition.
Bowed Floors:
Wood floors in a sagging condition.
Utility Dis/Re-connection:
When houses are raised, all utilities including plumbing, gas, and electrical lines must be disconnected and then reconnected properly to adjust to the new elevation. Vulcan provides this service.
Drainage Solutions:
Installing French drains or Yard drains to prevent standing water from ponding under, or adjacent to the structure.
French Drains:
Installing 4" inch perforated pipe connecting 12" X 12" pre-formed hard plastic or concrete catch basins with removable grates. Trenches are filled with 1" inch river rock or equivalent. The system is connected to a 4" inch line to the street or field line.
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Yard Drains:
Same as French Drains, but without the perforated pipe and rocks.
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Root Barriers:
Workers dig trenches 30" to 36" deep, cutting all tree roots. Hard plastic or rubberized sheeting material is then installed in the trench and the soil is re-packed.
Root Barriers prevent roots from growing under structures, de-hydrating the soil, and causing settlement.
Moisture Barriers:
Similar to Root Barriers, rubberized or hard plastic walls are constructed to keep water from flowing under a structure. Usually buried 18" to 24" deep, and sometimes installed in conjunction with a French Drain System.
Plumbing Repairs:
- Plumbing refers to the supply lines, which are usually in the attic.
- Sewer lines are the under-house drain lines.
Leaks in these systems can cause water to collect under the structure, creating mud, which undermines the foundation components and causes them to sink, lean, and crack. Vulcan has plumbers who provides sewer testing and repair.
Please review our Company Comparison Checklist for more information on the services available by Vulcan Foundation Repair.
Vulcan Foundation Repair - A trusted name for over 30 years.
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