Bridge Soft Subgrade Under Driveways, Parking Pads & Patios
Hit soft clay on a driveway, gravel parking pad, or patio job? Stop undercutting. Roll Tensar NX850 over the soft spot, place your stone, compact. Partial rolls stocked in Glenwillow, OH.
Short answer: Tensar NX850 geogrid rolled over soft clay or mud subgrade lets you build a stable gravel driveway, parking pad, or patio base without undercutting. The grid bridges the weak zone and confines your aggregate, so the base doesn't punch down, rut, or migrate. We stock partial rolls — quarter and half — out of Glenwillow, OH (44139) for residential contractors, small commercial jobs, and homeowners across Northern Ohio.
The soft-clay driveway problem
You dig for a driveway or patio, and instead of firm ground you hit soup — soft clay, wet silt, an old fill zone that never got compacted. The usual playbook: dig deeper, haul the mud out, buy more stone to bring the hole back to grade. That's a $1,000+ surprise, a half day of machine time, and no guarantee the base won't move once the freeze-thaw starts.
A roll of geogrid on the trailer changes that. When you find soft ground under a driveway or patio, you roll the grid across the soft area, place your stone on top, and compact like normal. The NX850's multi-axial apertures interlock the aggregate on both faces, so the base behaves like a stiff platform instead of loose stone sitting on jelly. A 15-minute install replaces a half-day fix.
Partial rolls — sized for residential jobs
Full contractor rolls of NX850 are 12.5 ft × 197 ft (~2,460 sq ft). That's too much for a driveway or patio. We cut it down so residential jobs get exactly what they need, nothing more.
Half roll
12.5 ft × 98.5 ft
~1,230 sq ft
Covers a two-car driveway up to about 20 ft × 40 ft (two 12.5-ft strips run the length). Room left for a patio or walkway.
Quarter roll
12.5 ft × 49.25 ft
~615 sq ft
Covers a single-car driveway up to ~12 ft × 49 ft (one strip), a patio pad, or a large shed base. Keep one on the trailer for the day you open a hole and find soup.
Same InterAx NX850 grid spec'd on ODOT roadway and airport projects — no residential downgrade. Pricing by square footage and pickup vs. delivery. Text your sq ft to (440) 384-1897 for a same-day quote.
Where residential geogrid pays off
- Gravel and stone driveways — stops stone migration into soft subgrade, prevents ruts and washouts.
- New asphalt and concrete driveways — stabilizes the base course so the surface doesn't crack from below.
- Paver patios — keeps the compacted base from settling and shifting through freeze-thaw.
- Walkways and garden paths — bridges soft or wet ground with a thin base instead of a full excavation.
- Shed, pole barn, and outbuilding pads — locks the base together under point loads.
- Parking pads for RVs, boats, trailers — a stable platform on Northern Ohio clay without over-building.
Gravel parking pads — RVs, boats, trailers, and yards
A gravel parking pad on soft ground fails the same way a driveway does. Stone punches down into the clay, ruts form under the tires, and every wet spring the pad needs another load of #57 to bring it back to grade. On an RV pad or a boat/trailer spot the loads are heavier and more static than a driveway — the aggregate keeps working its way into the mud.
Rolling NX850 under the base fixes it. The grid confines the aggregate so it stays put under long-parked loads, and it bridges the soft spots that would otherwise rut. Same product, same install, half the stone.
Typical parking pad sizes
- RV parking pad: 12 ft × 40 ft — one 12.5-ft strip. Fits a quarter roll.
- Boat / trailer pad: 10 ft × 25 ft — one strip. Well inside a quarter roll.
- Two-vehicle guest / employee pad: 20 ft × 40 ft — two strips ~80 linear ft. Fits a half roll.
- Contractor lay-down / equipment yard: 25 ft × 50 ft+ — usually 2-3 strips. Half + quarter, or a full roll.
- Small business overflow parking: Full roll (~2,460 sq ft) or larger.
Use the calculator below — set project type to "Gravel parking pad" and enter your dimensions to see stone savings and the exact roll size you need.
Driveway cost savings calculator
See what a soft-subgrade driveway costs the traditional way vs. building on Tensar NX850. Numbers use Northern Ohio residential defaults for stone and excavation — edit the assumptions to match your job.
Gravel base cost calculator
Works for gravel driveways, RV / boat / trailer parking pads, patios, and shed pads. Plug in your dimensions and subgrade condition. See what a traditional excavate-and-fill approach costs vs. building on Tensar NX850 geogrid.
Soft but not saturated. Typical Northern Ohio clay after a wet spring. CBR 1.0%.
Job size: 800 sq ft (89 sq yd)
NX850 rolls are 12.5 ft wide. Your driveway is 20 ft wide, so you'll lay 2 strips running along the 40-ft length = 80.0 linear ft of roll total. Leaves ~18.5 ft to keep on the trailer.
Text your dimensions to (440) 384-1897 for the exact price on this roll size.
| Excavation + haul-off | $1,333 |
| Stone (133.3 tons) | $4,667 |
| Total | $6,000 |
| Excavation + haul-off | $444 |
| Stone (44.4 tons) | $1,556 |
| NX850 partial roll | get quote |
| Materials subtotal | $2,000 |
NX850 partial-roll cost for a job this size runs a fraction of these material savings. Text (440) 384-1897 with your square footage for the exact number — same-day quote.
Per spec: Aggregate thicknesses match the Tensar 2025 Subgrade Pocket Card — the published NX850 design values for passing a proof roll (1" max deformation). Traditional depth = over-excavation (excavate soft material + backfill with stone, no grid). Grid-reinforced depth = NX850 stabilized base thickness at the same subgrade CBR. These are conservative for typical residential loads; the numbers hold up on commercial and DOT specs too. Stone volume converted at 1.5 tons/cubic yard (#57 / #304 limestone). Excavation rate is a loaded rate covering dig, haul-off, and tip fees. Grid layout assumes 12.5-ft-wide roll strips run along the driveway length. Numbers are planning estimates — actual job costs vary by site access, drainage, and delivery. Geogrid material cost not shown; text (440) 384-1897 for pricing.
Common questions
Can geogrid fix a soft or muddy driveway?
Yes. A biaxial geogrid like Tensar NX850 is laid directly over the soft subgrade, then covered with your aggregate base. The grid confines the stone and distributes vehicle loads across a wider area, so the base does not punch down into the soft soil. This bridges soft clay and prevents the ruts, sinking, and stone migration that show up after the first wet season.
How much geogrid do I need for a residential driveway?
NX850 rolls are 12.5 ft wide, so a 20-ft-wide two-car driveway takes 2 strips run along its length. A 40-ft-long two-car driveway = 80 linear feet of grid, which fits a half roll (12.5 ft × 98.5 ft). A 40-ft single-car driveway at 10 ft wide is one strip = 40 linear feet, which fits a quarter roll (12.5 ft × 49.25 ft). Use the calculator on this page for exact roll recommendations.
Why not just dig out the soft spot and fill with more stone?
You can, but on soft clay it is often a losing battle. Undercutting means an extra foot of excavation, truck cycles to haul out mud, more stone to bring the base back to grade, and it still moves later. Rolling geogrid over the soft subgrade and building the base on top bridges the weak zone in a fraction of the time, with less stone and no mud haul-off.
What is Tensar NX850 geogrid?
NX850 is a multi-axial (InterAx) geogrid manufactured by Tensar. It is a punched-and-drawn polymer sheet with hexagonal, triangular, and trapezoidal apertures that interlock aggregate on both sides. It is spec’d on ODOT roadway, airport, and heavy commercial jobs, and the same product works under residential driveways and patios.
Do you sell partial rolls of geogrid?
Yes. We stock quarter rolls (12.5 ft × 49.25 ft, ~615 sq ft) and half rolls (12.5 ft × 98.5 ft, ~1,230 sq ft) of Tensar NX850 for residential jobs. Full rolls rarely make sense on a driveway or patio, so we cut and sell smaller pieces from our Glenwillow, OH (44139) warehouse.
How much does geogrid cost for a driveway?
Pricing depends on square footage, project location, and pickup vs. delivery. Text or call (440) 384-1897 with your square footage and zip and you’ll get a same-day quote. Contractor pricing is available for repeat jobs.
Does geogrid reduce how much stone I need?
Yes, per the Tensar 2025 Subgrade Pocket Card. On soft subgrade (CBR 1%), a proof-roll-passing base without reinforcement takes 36 inches of over-excavation and stone backfill; with NX850 it takes 12 inches. On mild subgrade (CBR 2%), unstabilized needs 24 inches — NX850 needs 4–6. That translates to fewer truckloads of stone, less excavation, and less spoil to haul out.
Do you deliver to homeowners and residential contractors in Northern Ohio?
Yes. We serve Cleveland, Akron, Toledo, Youngstown, Canton, and the surrounding Northern Ohio counties from our Glenwillow, OH warehouse (zip 44139). Small partial rolls are easy to pick up in person if you’re close to Solon/Glenwillow.
Will geogrid work under pavers or a patio base?
Yes. Under a paver patio, the grid keeps your compacted aggregate base from spreading and settling as freeze-thaw cycles hit. It is one of the most effective ways to prevent the low spots and shifted pavers that show up after a couple Ohio winters on soft or wet ground.
Can I use geogrid under a gravel RV or boat/trailer parking pad?
Yes — parking pads are one of the best residential applications. RV and boat/trailer pads see heavy, long-duration static loads, which push aggregate down into soft subgrade faster than a moving vehicle would. NX850 confines the stone and bridges the soft ground so the pad stays level and does not rut or sink under long-parked loads. A typical 12 ft × 40 ft RV pad is one 12.5-ft-wide strip of grid and fits in a quarter roll.
How thick does the stone need to be over geogrid for a gravel parking pad?
Per the Tensar 2025 Subgrade Pocket Card, NX850 needs 4–6 inches of stone on mild subgrade (CBR 2%), 12 inches on moderate soft clay (CBR 1%), and 24 inches on severe wet clay (CBR 0.5%). These same depths apply to gravel parking pads. Without grid, the same subgrades need 24, 36, and 48 inches respectively. Use the calculator on this page for exact volumes.
What size roll do I need for a contractor lay-down yard or equipment storage pad?
A 25 ft × 50 ft lay-down yard is 2 strips of 12.5-ft-wide roll running 50 ft each = 100 linear feet, which fits in a half roll plus a small piece from a quarter, or a full roll (12.5 ft × 197 ft) with plenty left over. Larger yards typically buy full rolls. Text your dimensions to (440) 384-1897 for the exact recommendation.
Get a same-day quote
Text or fill this out with the square footage of your job and you'll get pricing back the same day — usually within a couple hours.
Authorized Tensar distributor. Glenwillow, OH (44139). Serving Cleveland, Akron, Toledo, Youngstown, Canton and Northern Ohio.