TxDOT Item 247 flexible base is the specification behind most road base placed on Texas roadway work, and knowing how it is organized keeps a bid and a delivery honest. Item 247 defines flexible base by type and by grade, with requirements for material source, gradation, plasticity, and strength. For contractors placing base under pavement, in parking areas, or on a graded pad across DFW, Austin, and San Antonio, speccing by the right type and grade is the difference between a load that passes and a load that gets rejected. This guide breaks down the types, the grades, and how to order it.
What TxDOT Item 247 Flexible Base Is
Item 247 is the TxDOT standard specification for flexible base, the compacted aggregate layer placed on the subgrade to support pavement. Flexible base, often just called road base or flex base, spreads traffic load and gives the surface a stable, well-drained foundation.
The spec matters because it defines what qualifies. When a plan set calls for Item 247 flexible base of a stated type and grade, the material delivered has to meet that classification. A product that looks similar in the stockpile but does not meet the spec is not a substitute.
Why Type and Grade Both Appear on the Plans
Item 247 separates two things: the type, which is mostly about the material source and how it is produced, and the grade, which is about the quality requirements the finished material must meet, such as strength and plasticity. A plan callout usually names both, for example a type and a grade together. Read both before pricing.
The Types of Flexible Base Under Item 247
The types describe where the material comes from and how it is made.
Type A
Type A is crushed stone produced from an approved source, made by crushing durable coarse aggregate. It is the most tightly controlled on source quality, which is why it shows up on higher-classification roadway work.
Type B
Type B is crushed or uncrushed gravel and can include a broader set of sources. It is common where the design allows a gravel-based product rather than crushed stone.
Type D and Recycled Materials
Type D covers a broader material class that can include recycled products such as crushed concrete, when the spec and the project allow it. This is where recycled crushed concrete can qualify as base, but only when the plans call for a type that permits it. Never assume a recycled product satisfies a Type A callout.
The Grades of Flexible Base
Where the type is about source, the grade is about performance. Grades set the thresholds for strength, plasticity index, and gradation. A higher grade carries tighter limits. The plans specify the grade so the finished, compacted base meets the strength the pavement design assumes. Two loads of the same type can carry different grades, so the grade on the plans is not a detail to skip.
How to Spec and Order Item 247 Flex Base in Texas
Speccing it correctly starts with the plans and ends with a delivered ticket that matches.
Read the Callout, Then Confirm the Source
Pull the type and grade from the plan set and the general notes. Then confirm your supplier can provide material from a source that meets that classification, with test data if the job requires it. On TxDOT work, material source approval and testing are part of the deal, not an afterthought.
Match the Delivery to the Spec
When the material shows up, the ticket and the product should match what the plans called for. Speccing by the generic words road base invites a mismatch. Speccing by Item 247 type and grade removes the ambiguity.
How Much Flexible Base You Need
Flexible base is ordered by volume converted to tons. Multiply length by width by compacted depth in feet to get cubic feet, divide by 27 for cubic yards, then multiply by roughly 1.4 to 1.5 tons per cubic yard. Because flexible base compacts, order for the compacted depth in the plans and add a modest allowance for compaction and waste, so you are not a load short at the end of a placement.
Getting the right classification to the jobsite on the day the crew is ready is the other half of the job. Coordinating the material and the trucking together, from a source that meets the spec, is how a base course gets placed and passes.
Spec the type, confirm the grade, and match the ticket, and Item 247 stops being a guessing game.
Need Item 247 flexible base to spec and delivered? Call 214-282-7980 or request a quote at aggregatesnow.com.