When to Choose Standard vs Custom Precast
The type of precast concrete products you choose across the design, bid, build continuum will ultimately impact the overall costs, deadlines, and compliance needs of your projects. Here’s what you should know before making a decision.
The benefits of precast concrete are well established among engineers and contractors. Precast products are more consistently uniform, require fewer onsite resources, and usually cost less than other available options. Cast in place methods may save you time and allow for more onsite configuring, but you will pay more for the additional workers it takes to build the structure while remaining at the mercy of whatever weather may come your way when casting.
What’s not as well established are the pros and cons of standard versus custom precast concrete products. Standard precast costs less and can be readily available, but it needs to fit exact specifications. Custom can be designed into virtually any structure, but it costs more to make and takes extra lead time to build.
There’s a third choice often overlooked by engineers and contractors: modified standard. When a project calls for only modest modifications to standard products, you can save on cost and time without impacting the outcome. During the design stage, for example, engineers can adjust project specifications to include standard products with modified components. During the build stage, contractors can install standard products more efficiently and still spend less time and cost by adding the modified components.
WHAT WE RECOMMEND
Your project demands will determine whether you need standard, modified standard, or custom precast concrete. Jensen recommends the following considerations based on our industry experience since 1968 as well as our onsite engineering staff with expertise in everything precast. We’ve partnered with thousands of businesses, communities, and agencies to solve their infrastructure challenges.
Precast concrete products are typically round, square, and rectangle. They come in a variety of standard dimensions and heights in 1’ tall increments with common riser sections of 6” and 12” and sometimes smaller 3” sections or larger 24” segments. By selecting a standard dimension and using modular components, we can usually configure a standard product to meet the project needs with less lead time.
Utility Boxes
Precast utility boxes come in many shapes and sizes. Jensen can fulfill your project requirements with off the shelf standards, modified products, or engineered to order structures meeting existing jobsite conditions or requirements.
The first consideration is the agency having jurisdiction. We carry a broad inventory of approved products that meet the standard plans or specifications for most local municipalities, government agencies, and utility companies. Selecting a preapproved product from Jensen assures contractors and owners have the most cost effective and available option. See our list of Agencies to find approved products.
If an approved standard does not exist, we offer many other standard products to meet the needs of your project. Examples include vaults, pull boxes, handholes, and equipment pads for dry utility applications. For wet utility projects we carry standard precast concrete manholes, catch basins, drainage inlets, pipe, and tanks.
When difficult or unique jobsite conditions exist, it is imperative to design a product to meet the site requirements. There are different design considerations for wet utility structures that will be containing water or wastewater versus dry utility products that will be housing utilities in pipe or conduit.
Considerations and options include:
- Sizes
- Loading conditions
- Access
- Openings (pipe, conduit, etc.)
- Inserts
- Concrete Materials
- Reinforcing
- Coatings/Liners
- Sealants
- Sumps
- Vent
Jensen provides a full lineup of products to meet your infrastructure design, bid, and build needs.
Grease Interceptors
Precast concrete battery grease interceptors feature standard steel tooling for commercial use with custom volumes and piping connections. Meets ASTM C1613 standard specification.
Drainage Junctions
Large rectangular grate inlets and junction structures feature standard steel tooling for drainage use with custom openings using standard steel tooling. Meets ASTM C890 standard specification.
Large segmented round structures feature standard steel tooling for drainage junction structure use with custom depths and custom openings. Meets ASTM C890 standard specification.
Battery Tanks
Precast concrete battery tanks feature standard steel tooling for drainage detention, retention, or infiltration use with custom volumes and custom openings. Meets ASTM C890 standard specification.
Wet Wells
Large segmented round structures feature standard steel tooling for wet well use with custom depths and custom openings. Meets ASTM C890 standard specification.
Box Culvert
Type 1 and Type 2 segmented box culvert features standard steel tooling for drainage detention, retention, or infiltration use with custom end walls, custom volumes, and custom openings Meets ASTM C890 standard specification.
Monolithic box culvert features standard steel tooling for drainage detention, retention, or infiltration use with custom infill slabs, custom end walls, custom volumes, and custom openings. Meets ASTM C890 standard specification.
Top reasons these type of products are accepted by contractors:
- Availability of special designs prepared by Jensen based on ASTM specifications for submittal to applicable agencies (engineers ease of specifying without having to provide structural designs and details).
- Reduced maintained time of open excavations.
- Contractor familiarity of installation methods and ease of installation.
Top reasons these products are not accepted by civil engineers:
- Civil engineers are unaware of Jensen’s willingness to take their specific design criteria (size restriction, volume requirements, and pipe opening requirements) and layout an appropriate structure utilizing standard steel tooling to economically solve challenges.
- Site civil engineers are reluctant to change already incorporated sizes in their drawings.
Standard, Modified Standard, or Custom
Whatever your project needs, Jensen has the experience and expertise to fulfill your requirements. We will recommend the best product type for your project to save you time and costs.
Contact us today at 775-352-2700 or through our website.
