TxDOT Item 432 Riprap: Bid Code Spec, Pricing and Post-Installation Requirements
Item 432 pays for riprap by the cubic yard, concrete, stone, cement-stabilized, or special, and the unit price carries more than the material itself. Toe wall trench excavation, all necessary excavation below natural ground or channel bottom, and slope shaping are all bundled into that same per-cubic-yard number, not priced separately. This covers the 6 bid codes that show up most often across recent TxDOT lettings, what separates one from the next, and one pricing pattern in the data worth double-checking before you rely on it, 18-inch stone protection riprap prices identically to 12-inch, despite requiring stone more than twice as heavy.
TxDOT Item 432 Bid Code Variants: What Determines Pricing
Item 432 covers four material types, and the spec is direct about it:
"Furnish and place concrete, stone, cement-stabilized, or special riprap."
Three things determine what you're actually pricing within that:
- Material type. Concrete riprap uses Class B concrete by default. Stone riprap splits into four named sub-types, R, F, Common, and Protection, each with its own stone weight range and placement method. Cement-stabilized riprap uses flexible base aggregate with 7 percent hydraulic cement by dry weight. Special riprap is whatever the plans call for. None of these price the same.
- Nominal thickness or size. Concrete riprap codes are named by thickness, 4 inch, 5 inch. Stone protection riprap codes are named by nominal size, 12 inch, 18 inch, tied directly to the weight and gradation tables in the spec. This is also how the item gets measured, by the cubic yard, computed from area in place times the thickness or toe wall width shown on the plans.
- Whether it's a named application, like "mow strip." Two of the six codes in this data are labeled Mow Strip rather than plain Concrete. Mow Strip isn't defined as a separate material type in the general Item 432 text, it's most likely a plans-designated application of concrete riprap, probably a narrow strip placed for vegetation and drainage control near guardrail or slope toes. Worth confirming against the plan sheet's own naming, but the pricing data is clear either way, Mow Strip prices 16 percent above plain concrete riprap at the same 4-inch thickness.
TxDOT Item 432 Pricing: Key Takeaways
- Excavation and slope shaping are bundled into the riprap price, not separate. Toe wall trenches, all necessary excavation below natural ground or channel bottom, and slope shaping are all inside the per-cubic-yard number.
- Mow Strip carries a real 16 percent premium over plain concrete riprap at the same thickness. Same material class, different application, different price.
- 18-inch stone protection riprap prices the same as 12-inch in this data, despite the spec requiring stone more than twice as heavy at 18 inch. Worth confirming with a larger sample before treating stone size as price-neutral.
- Bedding material is one of the few things on this item paid separately, not subsidiary, when the plans call for it.
- The first 5,000 square yards of stone riprap has to be tested and approved before you can place any more. A real sequencing gate, not a paperwork formality.
Cost Factors for TxDOT Item 432 Riprap
Cost Factors That Vary by Bid Code
Work through these one code at a time. They're what makes 432-7041 a different number than 432-7001.
- Material type. Concrete riprap needs formwork, reinforcement, and finishing labor. Stone riprap needs sourced and tested stone plus placement labor, no formwork. Different cost structure entirely, not just a different material line.
- Stone sub-type, if you're pricing stone riprap. Type R needs stones between 50 and 250 lb, at least half heavier than 100 lb. Type F needs the same weight range but with at least one broad flat surface on each stone, more selective sourcing. Common allows broken concrete from the project itself as a material source, when approved, which can be a real cost advantage. Protection uses boulders or quarried rock sized to Table 1's gradation bands, up to 4,400 lb maximum at the 36-inch nominal size.
- Void-filling technique, if it's stone. Dry riprap just fills voids with spalls and small stones. Grouted riprap gets grout worked into the voids after placement. Mortared riprap gets mortared as each stone goes in. The payment clause names all three as separate pricing bases, "type, nominal size, and void-filling technique... as applicable."
- Whether reinforcement is required. Concrete riprap typically carries welded wire fabric or rebar, spaced at a maximum of 18 inches each direction. Cement-stabilized riprap follows the same concrete provisions except when reinforcement isn't required, a real cost difference between the two material types even when both are technically "concrete-based."
- Broken concrete as a material source, where the plans allow it. Both Common and Protection stone riprap can use broken concrete removed under the contract or from other approved sources, when shown on the plans or approved. That's a potential cost offset worth pricing separately from a full-cost sourced-stone assumption.
Cost Factors That Apply to Every TxDOT Item 432 Bid Code
These don't separate one riprap type from another. They sit under all of them.
- A size verification test gates further placement, on stone riprap specifically.
"Perform a size verification test on the first 5,000 sq. yd. of finished riprap stone for all types of stone riprap at a location determined by the Engineer... Do not place additional riprap until the initial 5,000 sq. yd. of riprap has been approved."
That's a hold point built into the schedule, not a suggestion. - Slopes get dressed before riprap goes down, on every material type.
"Dress slopes and protected areas to the line and grade shown on the plans before the placement of riprap."
- Underwater placement needs its own approval, if the work is in or near water. Methods must be approved before installation, granular filter placement is restricted to clamshell or tremie methods to avoid segregation, and underwater granular filter work is only permitted below 5 feet per second water velocity unless separately approved.
- Filter fabric damage is cause for rejection. Any defects, tears, holes, or flaws found in filter fabric can get the material rejected outright, and repairs require a full additional layer of fabric with at least a 3-foot overlap beyond the damaged area in every direction, not a patch.
TxDOT Item 432 Payment Terms: Subsidiary Work vs. Separately Paid Items
This is where a bid priced off "riprap, per cubic yard" alone comes up short. The unit price carries far more than the visible material.
What's bundled into the riprap unit price, all of it, one number:
"This price is full compensation for furnishing, hauling, and placing riprap and for filter fabric, expansion joint material, concrete and reinforcing steel, grout and mortar, scales, test weights, equipment, labor, tools, and incidentals."
Filter fabric, reinforcing steel, grout, mortar, the testing equipment itself, all inside the riprap price.
The excavation bundling is the one worth pricing carefully, because it's easy to underprice.
"Payment for excavation of toe wall trenches, for all necessary excavation below natural ground or bottom of excavated channel, and for shaping of slopes for riprap will be included in the unit price bid per cubic yard of riprap."
That's real earthwork, toe wall trenches, sub-grade excavation, slope shaping, folded into the same number as the riprap material itself. If your estimate treats riprap as a materials-and-placement line and prices the excavation separately elsewhere, you risk double counting or, worse, leaving it unpriced entirely if nobody catches that it's supposed to live here.
Bedding material is one of the genuine exceptions, paid separately when required.
"When bedding is required for protection stone riprap, payment will be made at the unit price bid for 'Bedding Material' of the thickness specified. This price is full compensation for furnishing, hauling, placing, and maintaining the stone bedding material until placement of the riprap cover is completed and accepted."
Note what's not covered: excess bedding thickness and material lost to rain wash, wind erosion, or other causes get no separate payment.
TxDOT Item 432 Quality Gates and Placement Requirements
Item 432 doesn't carry Item 506's ongoing monitoring obligation or Item 666's measured performance requirement. Its risk shows up earlier, during construction itself, as quality gates that can stop placement if they're not cleared, and as placement methods the spec explicitly prohibits.
The 5,000 square yard hold point again, because it's worth planning around, not just knowing about. Stone size verification happens once, early, at a location the Engineer picks, and nothing past that first 5,000 square yards gets placed until it's approved. A crew mobilized to place riprap continuously across a job needs that approval built into the schedule, not treated as a formality that happens in parallel.
Protection riprap has explicit placement prohibitions, not just a preferred method.
"Do not place riprap in layers, and do not place it by dumping it into chutes, dumping it from the top of the slope, pushing it from the top of the slope, or any method likely to cause segregation of the various sizes."
Every one of those is a faster way to place riprap than the approved method, which is exactly why they're called out by name. A crew defaulting to the fast method is a rejection risk, not a shortcut.
In-place gradation can be checked after the fact, on Protection riprap. The Engineer can require verification of the finished stone gradation using linear transects, measuring at least 100 stones at 2-foot intervals, checked against Table 1's weight bands. That's a real possibility of a post-placement gradation failure on work that's already in the ground.
Grout and mortar work has its own weather gate. Placement only happens above 35°F air temperature, and the work needs protection from rapid drying for at least 3 days afterward.
Pricing Considerations for Quality Gates and Placement
- Sequence the first 5,000 square yards deliberately, since it's an approval gate the rest of the schedule depends on, not a parallel-track formality.
- Price placement labor for the approved method, not the fastest one, particularly on Protection riprap, where several common shortcuts are explicitly banned.
- Carry a contingency for in-place gradation failure on Protection riprap, since the verification can happen after material is already placed.
- Weather-gate grout and mortar work in your schedule, both the 35°F minimum and the 3-day drying protection period.
TxDOT Item 432 Bid Item Pricing Data
Average unit price across TxDOT lettings over the last 24 months. Each code links to its full pricing page, where you can see the spread by competitor, by district, and by quantity band.
Pricing Analysis: Key Cost Comparisons Across TxDOT Item 432
The useful comparisons are between codes that are identical except for one thing. Whatever gap shows up is what the market charges for that one difference.
Mow Strip prices 16 percent above plain concrete riprap at the identical 4-inch thickness.
Same material class, same nominal thickness, a real and consistent premium for whatever the mow strip application specifically requires, likely tighter tolerances or more linear, precision-placed work along guardrail or slope toe lines rather than open-area placement.
Concrete riprap thickness moves the price less than you might expect. 4 inch to 5 inch is a 25 percent increase in thickness, but only a 5.2 percent increase in price, $575 to $605. Worth remembering this item is priced per cubic yard already, so thickness is largely captured in the quantity, not the rate. A modest per-unit increase on top of that likely reflects finishing labor or formwork intensity rather than material volume alone.
18-inch stone protection riprap prices identically to 12-inch, and that's worth verifying before you rely on it.
The spec's own gradation table puts 18-inch stone at more than 2.6 times the maximum weight of 12-inch, yet both average exactly $213 in this data. That could mean stone size genuinely doesn't move placement cost much once sourcing is handled, or it could reflect a thin sample where these two codes haven't diverged yet. Either way, don't price an 18-inch stone protection job off the assumption that it costs meaningfully more than 12-inch until you've checked the spread behind this average, not just the average itself.
Executing TxDOT Item 432: Avoiding Rework and Ensuring Payment
For whoever's running the job. Same spec, stated as things to do.
Rework Triggers Under TxDOT Item 432
- Placing more than 5,000 square yards of stone riprap before the initial size verification test is approved
- Protection riprap placed in layers, or by dumping, chuting, or pushing from the top of the slope
- Filter fabric with any tear, hole, or flaw, cause for rejection outright
- In-place gradation on Protection riprap that fails verification after placement
- Grout or mortar placed below 35°F, or not protected from rapid drying for the required 3 days
Field Compliance Requirements for TxDOT Item 432
- Slopes and protected areas dressed to line and grade before any riprap placement begins
- Filter fabric oriented correctly for the application, long axis up-and-down slope for wave protection, parallel to centerline for stream bank protection
- Filter fabric kept free of tension, stress, folds, wrinkles, or creases during placement
- Underwater placement methods approved before installation, not after
- Reinforcement supported and adjusted during concrete placement to hold correct position, not just set and left
Pay Application Requirements for TxDOT Item 432
- Confirm type, nominal size, and void-filling technique on every invoice line, since the payment clause prices by all three together, not by riprap generically
- Separate bedding material from riprap in your documentation, since it's one of the few components on this item paid under its own unit price rather than bundled
- Track excavation and slope shaping as part of the riprap quantity, not as a separate earthwork line, since that's how the spec bundles payment
- Keep size verification test results on file for the first 5,000 square yards, that approval is the gate the rest of your placement schedule depends on
Built for people pricing and executing TxDOT riprap work
Frequently asked questions about TxDOT Item 432
What is TxDOT Item 432, Riprap?
It's the TxDOT spec covering concrete, stone, cement-stabilized, and special riprap, including the four stone sub-types, their materials and placement requirements, and the excavation and slope shaping work bundled into the same unit price.
Is excavation for riprap paid separately from the riprap itself?
No. Toe wall trench excavation, all necessary excavation below natural ground or channel bottom, and slope shaping are all included in the per-cubic-yard riprap price, not a separate pay item.
What's the difference between the four stone riprap types?
Type R and Type F both use 50 to 250 lb stones, with Type F requiring at least one broad flat surface per stone. Common allows broader sourcing, including approved broken concrete. Protection uses much larger boulders or quarried rock, sized by nominal class up to 4,400 lb maximum at 36 inches, and follows a stricter placement method.
Why does Mow Strip riprap cost more than plain concrete riprap?
In this data, Mow Strip prices about 16 percent above plain concrete riprap at the same 4-inch thickness. Mow Strip isn't formally defined as a separate material type in the general spec text, it's most likely a plans-designated application, likely reflecting more precise, linear placement work rather than a different underlying material.
Does larger stone size mean a higher price on Protection riprap?
Not clearly, based on this data. 12-inch and 18-inch nominal size stone protection riprap price identically here, despite the spec's own gradation table putting 18-inch stone at more than 2.6 times the maximum weight of 12-inch. Worth confirming against a larger sample before assuming size doesn't move the price.
Is bedding material included in the riprap price?
No, when bedding is required for protection stone riprap, it's paid under its own separate unit price, one of the few components on this item that isn't bundled into the riprap rate.
How much stone riprap can I place before it needs to be tested?
The first 5,000 square yards has to be tested and approved before any additional riprap can be placed, for all types of stone riprap.
Can broken concrete be used as riprap material?
Yes, for Common and Protection stone riprap specifically, when shown on the plans or approved, using broken concrete removed under the contract or from other approved sources.
How is Item 432 measured?
By the cubic yard of material complete in place, computed from the measured area and the thickness or toe wall width shown on the plans.
Is this pricing data free to use?
Yes. Every bid item pricing page linked above is free, no account needed.