We bought a house with a very large post oak right next to the front porch. Someone built a planter box around this oak (no idea whether it's been there as long as the house - 1961 - or is more recent). This winter I gently removed 2" of soil (the tree is buried about 2 feet deep) and already I felt a girdling root just below the next layer of soil. The root, even thet high up, is about 1/4" to 1/2" diameter.
1. I'm hoiping to pull a little soil away each year until the planter box is gone (will take a while!) so as not to shock the tree.
2. As for the girdling roots . . . sionce they are "thick" won't it hurt the tree if I cut these?
We cannot afford an arborist - trying to figure this one out without damaging the tree or our home!

I'm guessing you'd be safer in removing that girdling root than leaving it in place. Do be careful with all of that work, your slow approach is prudent. We've heard Howard say on the radio that post oaks are quite sensitive to change, but considering how long it may have been buried too deep, I think this change is only for the good.