Clarification on Geogrid and Filter Fabric Use

so they don't slide. Do you use that black matting in them, too? Depends. On the stone, depends. Depends on what the soil is like behind it. It's not a 100% for sure because if it's a heavy wet clay soil behind the the the boulders that that will this the silt from the clay will fill up the the fabric and then it'll it'll plug it up and create hydrostatic pressure behind the actual boulders themselves. Yeah. And can create problems. So, okay you guys, Frankie asked a really good question and I think I provided a somewhat confusing answer and so I want to make sure that we're pretty clear on what I'm actually talking about. A boulder retaining wall gets built exactly the same way as a modular block retaining wall in regards to geogrid. Geogrid always gets laid behind the retaining wall every 2 feet. And that rule of thumb is that you put one linear foot behind the wall for every linear foot of face wall. So that means if you have a 6ft tall retaining wall, whether it's boulder or modular block, your geog grid has to extend 6 ft behind it. And that geog grid has to be put in every 2 feet without fail. Not 3 feet, not 4 feet, every 2 feet or it's ineffectual. I hope that's a real word. But with a boulder retaining wall, you have one more step that you will never do on a modular block retaining wall, and that's to add a heavy filter fabric behind the face of the wall as you're building up. And the only reason that you would put filter fabric behind the face of the boulder retaining wall is to compensate for the gaps. You see, boulders don't tend to fit together snug. And so you'll need some kind of material in there that will help keep the soil from eroding through the face. But you've got to be careful because there's times when you want that fabric and there's going to be times when you don't want the fabric. The times you don't want the fabric is when you have a heavy soil that has a lot of silt because that soil can then plug up the fabric and lead to blowout. And that's exactly why you never use that fabric on a modular block retaining wall because the blocks fit together tight enough that they'll hold the soil back. They don't need any additional help. So that fabric can then become a liability. I hope that makes sense. You know, there's times like if it's a a sand or something like that or a sandy gravel or more of a porous material for sure cuz you want to keep the erosion from occurring between the boulders. But on a heavier clay type of soil, it can…