Installation Guidelines
Tensar's installation guide for TriAx geogrid in subgrade stabilization and pavement optimization, with the procedure changing according to how weak the subgrade is, measured as CBR.
Read the first page even if you skip the rest: it tells you to check the roll labels on delivery, because TX140 and TX160 look the same on a truck and are not the same product. Getting that wrong is expensive and nobody catches it once the grid is under fill.
The mechanism is worth understanding because it explains every rule that follows. Over soft ground the grid spreads load the way a snowshoe does. Over firmer ground it works by confinement, with aggregate locked into the apertures. That is why the guide is so particular about aggregate gradation and about getting real compaction on the first lift: the interlock is the product. A grid laid under the wrong stone is not doing the job it was specified for.
The other number to have in hand before you start is the minimum cover depth before equipment can track over the grid. Driving on it too early is the most common way to damage a section that was installed correctly up to that point.
Overlap on geogrid runs wider than on fabric, from about 1 ft on firm soils to 3 ft on poor ones, and it drives the quantity more than people expect. Our roll calculator will work the roll count out for whichever overlap you plan to run.
Road Fabrics stocks TriAx and the InterAx and H-Series grids that have largely replaced it. If you are not sure which one the spec actually calls for, our cross-reference tool matches it.
Tell us about your site and performance goals. Our team will match the right materials and installation approach, and get you a quote fast.
