Alliance Gator Grid 30-30 Biaxial Geogrid

Why Contractors Ask for Gator Grid 30-30 by Name

A block wall over about three feet is not held up by the blocks, it is held up by the reinforced soil behind them. Geogrid is what turns backfill into a structural mass.

• 2,052 lbf per ft (30 kN/m) ultimate tensile, ASTM D6637, in both directions. Biaxial means the number applies whichever way you run it.
• High-molecular-weight, high-tenacity polyester yarns woven in tension and PVC coated.
• No memory. Alliance rates it to lie 100 percent flat when unrolled, so it does not curl back while you are placing aggregate.
• Medium-height retaining walls, raised patio and staircase internal structure.
• Also for subgrade stabilization and erosion control.
• Four roll sizes from a 4x50 handroll to a 12x150 contractor roll.

Gator Grid 30-30 Specifications

Where Gator Grid 30-30 Works

Alliance rates Gator Grid 30-30 for:

• Medium-height retaining wall structure
• Raised patio internal structure
• Staircase internal structure
• Subgrade stabilization
• Erosion control and general landscape

How to Install Gator Grid 30-30

The full step by step guide is in the official documentation below. Here is the shape of the job:

1. Build to the engineered plan, not to a rule of thumb. Grid spacing and embedment length come from the stamped design.
2. Lay the grid on the compacted layer at the elevation the plan calls for, running back into the fill.
3. Anchor and stretch it so it is taut with no slack or waves before anything goes on top.
4. Place and compact the next aggregate layer, then set the next course of block and repeat.

30-30 or 50-50? Which Geogrid Grade

Both are biaxial polyester grids from the same family. The difference is strength and therefore what they are approved for:

• Gator Grid 30-30 — 30 kN/m each way. Medium-height walls, raised patios, staircases, subgrade stabilization. Available in a 4x50 handroll.
• Gator Grid 50-50 — 50 kN/m each way. High, single and multi-level engineered walls, steep-slope erosion control, roadway and parking structure. No small roll.
• The honest answer is that your engineer picks this, not a website. If nobody has run the numbers on your wall, that is the thing to fix first.

Quick Answers

What does 30-30 mean?
30 kN per metre ultimate tensile strength in each of the two directions, which is 2,052 lbf per foot. Biaxial, so orientation does not change the rating.

Do I need an engineer?
Alliance says yes, explicitly: a soil analysis before the project, and a stamped plan from a qualified local engineer before you set grid placement.

Can I use the placement table on the label?
Not on multi-tiered walls, and not where there is excess runoff, seepage or springs, unless an engineer confirms it.

30-30 or 50-50?
30-30 for medium-height walls, 50-50 for high or engineered multi-level walls. Your engineer specifies which.

Does it need to be stretched?
Yes. Alliance calls for anchoring and stretching before the next layer of aggregate and block goes on. Slack grid does not carry load.

Which way round does it go?
It is biaxial and rated the same both ways, so orientation does not affect strength. Run it perpendicular to the wall face into the fill.

Official Alliance Gator Documentation

Documents are published by Alliance Gator. For the most current versions, visit alliancegator.com.

Pairs Well With

• Gator Grid 50-50 — the heavier grade for engineered walls.
• Gator Fabric GF5 — woven reinforcement fabric for the leveling pad.
• Geogrid and wall drainage — the full range.

Questions about your project? Call or text (856) 418-4895 and you will get a real person who works with geogrid every day.