I don't know what our regulations are. Under normal circumstances the regular rain patterns and drainage are enough to keep our foundations stable. At the beginning of the 2010s we started a drought that lasted many years. We might technically still be in it, but I doubt it. This has been a very very wet year so far. My foundation was poured in 1996 and there were zero trees around here back then. It was wide open hot ass Texas land. Now it's a neighborhood with massive trees everywhere.JD01 wrote: ↑Tue Jun 29, 2021 12:19 pm
Swell or shrink... the important thing is that after your foundations are poured you don't want the soil to change volume 'cos that's where your problems start! We have a LOT of high plasticity/volume change potential clay all over the place here and we have really strict regulations about foundation depths and how close to trees you can get.
Everyone talks about root action with trees affecting foundations - in clay, soil desiccation and shrinking is a way bigger issue.
When I was a kid in New Orleans you couldn't even dig a hole without it filling with water. People are "buried" above ground over there.