A Contractor's Guide to Precast Concrete Products and How to Choose a Supplier
This guide is designed to assist contractors throughout New Hampshire, Maine, and Massachusetts with selecting the best precast concrete manufacturer for their needs. It outlines the advantages of precast concrete; answers frequently asked questions about precast concrete products and suppliers; describes eight common products precast suppliers stock; and explores the benefits of working with a quality precast concrete supplier, including a checklist of questions to ask before hiring a precast concrete manufacturer.
Our five decades of experience with supporting contractors and septic system designers throughout New England has contributed thousands of successful commercial and residential construction and wastewater management projects.
Answers to 5 Frequently Asked Questions about Precast Concrete Suppliers & Products
What affects the structural integrity of precast concrete?
Key components that affect the structural integrity of precast concrete products include:
- Grade of steel: Grade 40 yields a min. 40,000 lbs./sq. in; Grade 60 yields min. 60,000 lbs./sq. in.
- Size and spacing of steel reinforcing bar (rebar): Sizes #3, #4, #5 , and #6
- Location of steel in concrete: In the top, bottom, and walls of a structure
How can a precast concrete supplier save a contractor time and money?
- Value Engineering – Experienced precast concrete manufacturers strive to learn the needs and goals of each project, and work to provide cost effective solutions or alternatives to enhance each project. For example, if the project plans specify all concrete chambers are 4-ft x 8-ft, a precast concrete professional may suggest using 8-ft by 8-ft units, to save the contractor approximately one-third of the cost. This type of value engineering enables contractors to lower their costs to earn more projects.
- Plan Analysis and Cost Estimation – Experienced precast concrete providers can greatly ease the burden on contractors by comprehensively analyzing project plans and efficiently itemizing all needed products and pricing.
What guidance & support can a precast concrete manufacturer provide to contractors?
- Education and guidance regarding products, process, and installation
- Plan analysis and value engineering of cost-effective alternative solutions
- Septic tank sizing guidance and tools
- Product drawings on USB or online with 24/7 access, in AutoCAD and PDF file formats
What is H20 and HS20 traffic-rated loading?
- H-20 Loading is defined by the American Association of Highway and State Transportation Officials (AASHTO) as a vehicle load with an 8,000 pound front axle and one rear axle weighing 32,000 pounds representing a 16,000 pound wheel load.
- HS-20 loading is defined as a vehicle load with an 8,000 pound front axle and two rear axles weighing 32,000 pounds each representing two 16,000 pound wheel loads.
What should a precast concrete manufacturer provide with a traffic-rated tank?
A precast concrete manufacturer should provide documentation of the tank’s testing and a diagram of the tank’s design, to verify that it can withstand HS-20 loading, and has been built with the appropriate rebar size, grade, lengths, bends, and placement to ensure reliable performance.
Why Precast Concrete is the Best Choice
13 Advantages of Precast Concrete Products and Septic Tanks
As detailed fully in our article about choosing the right septic system for a New England property, the section titled 13 Advantages of Precast Concrete underscores these reasons why precast concrete makes the most sense for New Hampshire, Maine and Massachusetts:
- COST EFFECTIVE
- RESISTS BUOYANCY
- FIRE RESISTANT
- CONTROLLED for QUALITY and UNIFORMITY
- NOT UV SENSITIVE
- ENVIRONMENTALLY FRIENDLY
- WEATHER RESISTANT
- INSTALLS QUICKLY AND EASILY
- READILY AVAILABLE
- LOW MAINTENANCE
Benefits of Working with a Quality Precast Concrete Manufacturer
Consistent High Quality 5,000 PSI Concrete
Quality precast concrete companies follow the Best Practices of the National Precast Concrete Association (NPCA) to develop long-lasting, effective solutions for modern wastewater treatment system construction.
Precast concrete is manufactured in a controlled environment, ensuring reliable consistency and quality.
Variety & Availability of Precast Concrete Products
In-stock availability of a wide variety of precast concrete products is critical to the success of many projects. It is beneficial for a contractor to partner with a precaster that regularly stocks in-demand products ranging from single compartment to two- and three-compartment tanks; to customizable manholes and concrete catch basins; to innovative technologies such as advanced treatment units.
Competitive Pricing and Value Engineering for Septic Systems
Dedicated precast concrete professionals make it their business to identify value-engineered solutions and alternatives that enhance a project and save time and cost. For example, when a designer specifies a product that isn’t locally used or available, or is cost prohibitive to custom-manufacture, an experienced concrete precast provider can suggest ways to modify a stock item, or to use an alternative structure.
Innovative Solutions and Product Alternatives
Examples of innovations and alternatives proven to save time and cost while increasing performance include:
- Built-in plastic risers ensure a watertight septic tank, from the top down
- Creation of 2 and 3-compartment septic tanks for better separation using fewer structures, to enable a smaller footprint and cost savings due to less excavation and plumbing
- Innovative installation and use of pump stations in a wide variety of tank sizes and combinations
- Fiber reinforcement built into every septic tank
- Construction with rubber flexible connections
- Advanced Treatment Unit (ATU) for use with a Norweco Singulair System, to accommodate small lots, waterfront lots, environmentally restrictive areas and high water tables
Flexibility of Design for Septic System Designers
Skilled precast concrete professionals provide septic system designers with flexibility. For example, flexible septic tank design enables designers to plan for the effluent to exit either from the side or end of the tank, via three inlets and three outlets.
Same or Next Day Delivery of Precast Concrete Products to Project Site
Rapid delivery of in-stock products eliminates wait times, and streamlines projects when contractors are ready for installation.
Comprehensive Guidance & Support for Contractors and Septic System Designers
Experienced precast concrete companies understand the importance of maintaining strong relationships with builders, contractors, and septic system designers.
Examples of how precast concrete professionals can comprehensively support contractors include:
- For new contractors – Provide educational services to help them establish their business. For example, walk through a project site; discuss septic system hole placement; and comprehensively review the installation process to ensure successful results.
- For experienced contractors – Analyze plans and provide value-engineered, cost-effective alternative solutions that streamline and enhance each project
- Provide septic tank sizing guidance and tools
- Provide a USB drive containing a product’s drawings, in AutoCAD and PDF file formats
- Provide no-cost online account activation, for contractors and designers to download AutoCad files
- Provide a Pump Station package with system dimensions, features, control panel and components
- Support designers by helping to specify the appropriate pump and accessories
Warranty on Precast Concrete Components of Septic Systems
Reputable precast concrete manufacturers will provide original purchasers with an exclusive limited warranty on the structural integrity of each underground concrete structure when installed in accordance with the manufacturer’s instructions. This warranty is typically against defective materials and workmanship for a period of one year from the purchase date. If a defect appears within the warranty period, and the purchaser informs the precast concrete company within a specified time period (typically 15 days), a reputable manufacturer will typically repair or replace the unit, with a value not to exceed the original purchase price, and excluding the liability of the removal and/or installation of the unit. Be sure to discuss other warranty terms and conditions before choosing to partner with a precast concrete company.
Experience with State Regulations in NH, MA, ME and VT
Each state has specific regulations and requirements regarding septic system design, products and installation. For example, it’s critical that a precast concrete supplier can custom-design precast concrete tank sizes to accommodate the specific requirements of the state of New Hampshire.
8 Common Products Precast Concrete Companies Stock
The best precast concrete companies understand the importance of having key products in-stock and ready to modify or deliver whenever contractors need them. Here are the eight most common products that contractors commonly request from their precast concrete supplier – including alternate names for each product, as well as typical applications and uses.
 H-20 Traffic Rated Septic Tanks
A precast concrete septic tank is a single or multi-compartment holding chamber that collects wastewater from drains and toilets. The treatment chamber is where the natural biochemical treatment of solid and liquid influent begins, and effluent is then discharged to a drain in an area covered by soil, below the surface.
Many projects call for precast concrete septic tanks to be installed below a vehicular traffic area, thus requiring that the tanks be manufactured to the specifications of H-20 or HS-20 traffic-rated loading.
Septic tanks designed to handle traffic-rated loads have thicker side walls and bottom and top slabs, and are ideally manufactured with quality high-strength 5,000 psi concrete using Type III cement. Specialized equipment is also required to handle the additional weight of traffic-rated tanks.
H-20 Septic Tanks are Also Known As:
- Traffic rated tanks
- Load-bearing tanks
- Traffic-bearing tanks
- Drive-over tanks
Applications and Uses for H-20 Septic Tanks:
- Commercial projects
- Convenience stores
- Decentralized wastewater treatment
- Gas stations
- Office or Shopping Mall projects
- Parking lots
- Shopping plazas
 Frost Posts
Precast concrete frost posts (also called deck footings, deck piers, frost piers and sonotubes) are often used to support decks and porches. For these applications, frost posts are installed in the ground below the frost line, exposing only the tops of each post. Quality frost posts are precast with high-strength 5,000 psi concrete mix using type III cement.
Benefits of Precast Concrete Frost Posts
The advantages of installing precast concrete frost posts instead of posts created onsite with ready-mix concrete include:
- Versatility – Precast concrete frost posts may be installed in all weather
- Quality and Dependability – Posts are produced with high-strength 5000 psi concrete mix
- Time Savings – Avoid the coordination and scheduling that ready-mix concrete demands
- Ease and Speed of Installation – Precast concrete frost posts come with footings and anchor cast
- Size Availability - Choose from three sizes: 8 or 10-inch square profiles, or a 10-inch round profile
Frost Posts are Also Known As:
- Deck footings
- Deck piers
- Frost piers
Applications and Uses for Frost Posts:
- Deck support
- Entrance Columns
- Farmer’s porch support
- New construction
- Pole barn
- Shed support
- Entrance Columns
 Concrete Chambers
The role of a concrete chamber (also called a flow diffusor, leaching chamber, or shallow dry well) is to effectively leach septic tank effluent into the ground. Long-lasting, reusable concrete chambers have reliably served as leach fields for more than 50 years.
Not all precast concrete manufacturers produce concrete chambers, so it’s an important question to ask when choosing a precast concrete supplier. Contractors prefer to partner with a precasters that regularly stock and supply concrete chambers – often in large quantities, on short notice. For example, large commercial projects such as shopping mall parking lots can demand upwards of 100 traffic-rated concrete chambers, on a tight schedule.
Benefits of Concrete Chambers:
The advantages of installing precast concrete chambers instead of alternate designs such as pipe and stone include:
- Enables Vehicular Traffic – (H-20 tanks are rated to withstand vehicular traffic)
- Footprint Reduction – Allow for leach field size reduction in NH & Maine, versus pipe & stone design
- Effective Design – Side holes allow for liquid to seep out of the chamber sides as well as the bottom
- Size Availability – Common sizes of concrete chambers include:
- 8' x 8' x 13"
- 4' x 8' x 13"
- 4' x 8' x 18"
- 4' x 8' x 13"
- 4' x 12' x 13"
Concrete Chambers are Also Known As:
- Flow diffusors
- Flow diffusers
- Leaching chambers
- Shallow dry well
Applications and Uses for Concrete Chambers:
- Absorption field
- Dispersal field
- Drain field
- Leach field
Bulkheads (also called bulkhead steps, precast basement entry steps, and precast or pre-made basement entry stairs) are precast concrete staircases that enable access to a basement. Installation of bulkheads requires precision and skill to ensure a watertight fit. Therefore, not all concrete manufacturers are willing or able to produce bulkhead steps, so it’s important to ask a precast concrete supplier if they provide bulkheads in several standard industry sizes before you choose to partner with them for your projects.
Bulkheads are Also Known As:
- Basement entry steps
- Precast basement entrances
- Precast basement stairs
- Pre-made basement stairs
- Precast concrete stairwell
Applications and Uses for Bulkheads:
- Basement access
- Basement entry
- Retro-fit basement access
 Catch Basins
A catch basin (also called a drop inlet, drainage inlet, storm drain, or storm water catch basin) is a square box precast concrete structure placed below-ground, with a horizontal square opening. Catch basins are typically stocked as set-size items, ready for quick-modification to the required size specifications for each hole.
A slotted or perforated metal grate is often set into the top of a catch basin, to bring it to ground level and enable water to enter the structure. In a heavy rainstorm, water will drain from the surface into the grate openings of the catch basin, and then into a storm water pipe that is connected to the catch basin. Many storm drains can be linked with pipe, creating a system of gravity-fed drainage points.
Benefits of Precast Concrete Catch Basins:
- Enables Vehicular Traffic – Precast concrete catch basins are H-20 rated to withstand vehicles
- Time Savings – A precast concrete catch basin is quick and easy to install, with tight pipe-to-structure connections
- Quality and Dependability – Produced with high-strength precast concrete
- Ready to Install – A drop inlet catch basin is produced to be ready-for-installation. (Catch basins are typically made to order; however, a quality precast concrete manufacturer will stock “blanks” that can be custom-cored to create holes at required heights and elevations based on project specs
- Several Sizes Available for Various Design Parameters:
- Flat top cover sizes range from 1 to 4 ft.
- Riser sizes range from 1 to 4 ft.
- Base sizes range from 2 to 5.5 ft.
Catch Basins are Also Known As:
- Drainage inlet
- Drop inlet
- Storm drain
- Storm water catch basin
Applications and Uses for Catch Basins:
- Catching ground water
- Detention pond outlets
- Gas stations
- Parking lots
- Shopping malls
Precast concrete manholes (also called pump stations, sanitary manholes, sanitary sewers, and storm water manholes) are a key component of a wastewater treatment system. They are produced in a controlled environment, which ensures consistent quality and consistency. When properly designed and installed, precast concrete manholes provide durable, watertight performance. Manholes are typically stocked as set-size items, ready for quick-modification to the required size specifications for each hole.
Manholes are Also Known As:
- Pump station
- Sanitary manhole
- Sanitary sewer
- Storm water manhole
Applications and Uses for Manholes:
- Diverting effluent water to treatment plant
- Wastewater management systems
- Town sewer system
 Grease Interceptors
The role of a precast concrete grease interceptor (also called a grease trap, gravity interceptor, passive interceptor, and precast interceptor) is to remove grease from the waste stream before water is discharged into a septic system. A grease interceptor/trap is a septic tank customized to settle the water and grease, enabling the water to cool down before it is released into a leach field.
Benefits of Precast Concrete Grease Interceptors:
- Strength and vehicular load-bearing capacity
- Quality watertight solution
- Ease of maintenance, with available monitoring system
- Resistance to Buoyancy
- Environmentally Safe
Grease Interceptors are Also Known As:
- Grease trap
- Gravity interceptor
- Passive interceptor
- Precast interceptor
Applications and Uses for Grease Interceptors:
- Gas stations
- Coffee shops
- Convenience stores
- Shopping plazas
 Trench Drains
The role of a trench drain (also called a channel drain, concrete drainage trough, or concrete drainage channel) is to collect excess water from parking lot or driveway, and direct it to a small-scale catch basin. Non-contaminated runoff is directed to a dry well/leaching chamber for water disbursement. Contaminated runoff is directed to an oil/water separator before water is directed to a dry well or city drain/catch basin.
Benefits of Precast Concrete Trench Drains:
- Designed for H-20 vehicular loading
- Available in a variety of larger sizes
- Ready to install without the additional preparation that plastic encasement requires
- Chamfered open sections allow for a smooth transition after mortaring the joints
- No unsightly mortar joints that allow for build-up of leaves and silt
- Unaffected by UV rays, unlike plastic
- When properly installed, prevent damage to snowplows and property
Trench Drains are Also Known As:
- Channel drains
- Concrete drainage troughs
- Concrete drainage channel
Applications and Uses for Trench Drains:
- Car washes
- Convenience stores
- Ends of driveways to collect storm (rain) water
- Gas Stations
- Mall Plaza
- Parking Lots
- Shopping Plazas
Checklist: What to Ask Before You Hire a Precast Concrete Company
Before you partner with precast concrete company to support your projects, here are 7 key questions that will help you assess their commitment to quality, integrity, and service:
Is your firm a member of the National Precast Concrete Association?
Membership in the National Precast Concrete Association (NPCA) indicates that a firm is committed to the high standards of continuing education and best practices in their manufacturing processes.
Do you currently stock the 8 Common Products Precast Suppliers Stock?
The most reliable precast suppliers offer in-stock availability of commonly-specified products, including H-20 Traffic Rated Septic Tanks; Frost Posts; Concrete Chambers; Bulkheads; Catch Basins; Manholes; Grease Interceptors and Trench Drains.
How quickly can you manufacture custom products?
The best precast concrete firms can manufacture custom products within two to four weeks.
Do you offer a warranty on your precast concrete products?
The best providers of precast concrete products proudly offer a warranty on their products, as a tangible testament to the quality of their offerings.
What is your typical delivery schedule?
The best precast concrete providers offer same day or next-day delivery, within a one-hour time frame.
What support do you offer for contractors?
Precast concrete professionals communicate well and maintain strong relationships with contractors. Ask these questions to learn about their dedication to contractor-support:
- Do you take the time to educate new contractors, and discuss the process for each project?
- Do you provide value-engineered, cost effective alternative solutions to streamline each project?
- Do you provide septic tank sizing guidance and tools?
Do you offer access to product drawings and dimensions?
A customer-oriented professional precaster will provide contractors and septic system designers with product drawings, in AutoCAD and PDF file formats, on USB as well as via a free online account with around the clock access.
ABOUT THE AUTHOR:
Jonathan Cardinal is Operations Manager and Co-owner of A.J. Foss (www.ajfoss.com), a family owned and operated precast concrete products manufacturer located in Farmington, NH. For more than 50 years, A.J. Foss has served contractors, specifiers and designers throughout New Hampshire, Maine and Massachusetts with innovative, value engineered and cost-effective solutions for their precast concrete needs, as well as education and guidance regarding products, processes, and installation.