If you are spec’ing or buying base material for a Florida site, you have three primary choices: limerock, shell (or shell rock), and crushed concrete. They all do the same fundamental job – provide a stable load-bearing layer under pavement, slabs, or building pads – but they are not equivalent. The right choice depends on the project specification, the source quarry’s reach, and what your geotechnical engineer is asking for.
Here is what each material actually is, where it makes sense, and what to watch for when you order it.
Limerock: the Florida standard
Limerock is mined from Florida’s limestone formations, crushed to a specified gradation, and used as base or sub-base under roads, parking lots, and structural pads. It has been the default Florida road base material for decades because the state sits on enormous limestone reserves and the material has predictable engineering properties.
FDOT measures limerock quality with the Limerock Bearing Ratio (LBR) test, documented in Florida Method FM 5-515. The LBR is calculated against the strength of a standard reference limerock, with a typical certified road base falling in the 100 to 170 LBR range depending on source and specification. The higher the LBR, the more load the base can carry before failing.
Limerock is the right answer when:
- The specification calls for a certified FDOT base material
- The project is in central or south Florida where limerock quarries are nearby
- The engineer is sizing the base layer using LBR design assumptions
- The owner wants a material with a long-established performance record in Florida soil and climate
Watch-outs: limerock quality varies by source. A LBR-100 limerock from one quarry will not behave the same as LBR-150 limerock from another. If your spec calls for a specific LBR, get a material certification with each delivery, not just a verbal assurance.
Shell and shell rock: coastal Florida’s alternative
Shell – typically crushed oyster shell or coquina mined from coastal deposits – has been used in Florida road and pad construction since long before there was an FDOT. Modern shell rock is a blend of crushed shell and limerock that provides similar engineering properties to limerock with the benefit of local sourcing in parts of the state where limerock has to be trucked long distances.
Shell rock is the right answer when:
- The project is along the coast or in regions where shell deposits are local and limerock requires a long haul
- The specification permits a blended shell-limerock base (most FDOT and local jurisdiction specs accept properly graded shell rock for non-structural and certain structural applications)
- Cost per delivered ton matters and the closer source wins on freight
Watch-outs: shell content can vary, and pure shell without limerock blending has lower bearing capacity than properly graded shell rock. Always confirm the supplier is producing to the gradation and bearing requirements in your spec.
Crushed concrete: recycled, sustainable, often the highest LBR
Crushed concrete – formally recycled concrete aggregate, or RCA – is exactly what it sounds like. Demolished concrete from old roads, slabs, and structures is crushed, screened to size, and reused as base material. FDOT Section 911-2.7 covers RCA composition for road base, and RCA that meets Florida gradation requirements can be designated as a B12 product for use as road base aggregate.
Properly produced RCA frequently tests at LBR values well above 200, higher than typical limerock. The material has gained acceptance on FDOT and local projects over the past decade as both a high-performance base and a sustainable alternative to virgin aggregate.
Crushed concrete is the right answer when:
- The specification permits or requires RCA (check the project documents)
- You need high bearing capacity and the spec is LBR-driven
- Sustainability or LEED credits matter to the owner
- A producing crushing facility is close enough to make the haul economical
Watch-outs: RCA quality is only as good as the source concrete. A producer who is crushing clean structural concrete makes a different product than one who is crushing mixed demolition debris with rebar fragments and contaminants. Ask the producer about their source streams and their quality control before you commit to using RCA on a project that depends on the base performance.
How to actually pick
The decision usually gets made in this order:
1. Read the spec. If the project documents call out a specific material – say, “FDOT certified limerock base, LBR 130 minimum” – your choice is largely made. Substitutions require approved change orders.
2. Check what is locally available. Limerock that has to come from 80 miles away does not beat shell rock that comes from 15 miles away on cost per delivered ton, no matter how the base specs compare. Trucking is often the larger fraction of delivered material cost.
3. Talk to your hauling partner about delivered economics. A good hauler knows which quarries and crushing facilities are running, what their current pricing looks like, and what the realistic haul time is. That information shapes the right material choice as much as the engineering does.
4. Confirm the certification documentation. Whichever material you pick, you want certs in hand showing the material meets the spec. Owners and inspectors will ask, and “the supplier said it meets spec” is not a paper trail.
The hauling side matters more than people think
Base material moves in volume. A typical commercial pad needs hundreds of tons; a road project needs thousands. The hauler you pick determines how predictably the material shows up, whether you have the right tickets for owner billing, and whether the trucks are sized correctly for the site access. Tri-axle dump trucks are the standard for base rock delivery in Florida because they hit the right balance of payload and maneuverability, but pickup location and dispatch reliability matter just as much.
T. Disney Trucking hauls limerock, shell, crushed concrete, and fill from quarries and crushing facilities across the state. From our Riverview, Fort Myers, and Williston yards, we cover central, southwest, and north-central Florida with consistent dispatch and clean tickets. If you are pricing out a base material decision, we can usually help you sanity-check the delivered economics before you commit.
Need limerock, shell, or crushed concrete delivered for a Florida project? Contact T. Disney Trucking at +1-(844) 258-7825 or visit disneytrucking.com for quarry options and delivered pricing.
Frequently Asked Questions
What is the difference between limerock and shell rock in Florida construction?
Limerock is mined from Florida’s limestone formations and crushed to spec. Shell rock is a blend of crushed shell (typically oyster or coquina) and limerock that achieves similar engineering properties using more locally available coastal materials. Both can meet FDOT base specifications when properly graded.
What LBR value does FDOT-certified road base need to meet?
FDOT certified base materials are typically tested using FM 5-515 and reported with an LBR value. A typical certified limerock base falls in the 100 to 170 LBR range, with the specific minimum determined by the project specification. Always work from the project documents, not a general rule of thumb.
Can recycled concrete aggregate be used as road base in Florida?
Yes. FDOT Section 911-2.7 covers RCA composition for road base, and properly produced RCA meeting Florida gradation requirements can be designated a B12 product for road base use. Verify the spec on your specific project before substituting RCA for virgin aggregate.
How is base material priced in Florida?
Pricing has two components: material cost at the quarry (priced per ton) and delivered freight (priced per ton-mile or per load based on haul distance). On long hauls, freight often exceeds material cost, which is why locally sourced material frequently wins even when the per-ton quarry price is higher.
What documentation should I get with a base material delivery?
For FDOT or municipal work, you want a material certification matching the spec (LBR, gradation), source quarry identification, and load tickets showing weight per load. Keep tickets organized by date and source – owners and inspectors will request them during closeout.
