I had a 50 or so ft. pecan tree removed and had the stump ground in order to make room for a shop. They ground the stump down about 8 in below grade. My question is, who has the best/easiest solution (shy of hiring someone to do it) for removing all of the roots? Can it be done with a mini excavator? Any special attachments worth getting? What size excavator can handle it?

It probubly won't remove all the roots but a little gas/diesel fuel mix and fire will burn alot of the major roots out without tearing up your yard.

This summer I dug up the root ball of a 40' Ailanthus (http://en.wikipedia.org/wiki/Ailanthus) or "Tree of Heaven" that was growing into my basement. Check out the link, they are truly vile trees. The things grow so fast that in the first two weeks of spring it nearly caved in my wall in the basement, but had shown no previous damage at all. I had to dig it up to fix the foundation and I did it by hand, with a shovel, a root spade, mattock and sawsall. Kept tugging on it with a loader every few feet and it finally gave. I left about 6 foot of trunk for leverage though. The key is to dig out all around it, I would get a really long ass prybar and start digging. It is no fun, but it can be done. By the time you rent a mini bobcat type excavator and wreck the shit out of your yard, you will end up having more money into it then hiring a guy with a back hoe.

Most root systems go out to the edge of where the trees canopy used to be, however they typically do not go anywhere near as deep as people assume they do.

Later,
Jason

I have no idea if they still sell it or not, but years ago when I worked in a Hardware store we sold "Stump Remover" made by Ortho? maybe? You drilled some holes in to the stump and poured the stump remover into it. It would speed up the decomposition and make it easire to burn, and or remove. It takes a few weeks to work though. Not sure how far down the roots it goes though.

Edit: Found it, or something similar:
Stump-Out
Just drill a few holes in the stump and pour in StumpOut®. It decomposes the wood in a few weeks, leaving holes all the way down. Then drop in a match to burn the pulp. Some chopping may be required on larger stumps. Nonexplosive, dry granular formula. 1lb. can for one stump.

I believe what he's asking is how to get the roots that stretch across his yard out, as the stump was already ground away.

Surface roots (those that are either above or just under the sod) can be removed with an axe, shovel, pick, and sweat.

I had two large 30-40 foot locust trees in my front yard (they too are just nasty, dirty trees) that had become a royal pain in my arse. The company I hired chipped the stumps out, but the roots extended 20-30 feet across the yard. I don't know if a mini excavator will be able to rip them out. The cement company that replaced my driveway and sidewalks had a small tractor/backhoe that they used to rip them out from under the old drive and walks.

They will eventually rot away...Years from now depending on how large they are. Some of mine were 6" in diameter.

A mini excavator will do the trick. It depends how big the root ball is. A bobcat 331 or equivalent is as small a machine as I would use, anything bigger will make the job a little easier. Get a narrow bucket for digging around the rootball and ripping up the roots. If the rental place has one with a thumb get it makes it easier to clean up all the debris.
At work with a jd 200 and I still have to dig around the rootballs to pop them. Sometimes I use the frost ripper to shred the roots.
Have fun with the mini if you rent one they are great to learn in and you can do a few other jobs around the yard.

I had a 50 or so ft. pecan tree removed and had the stump ground in order to make room for a shop. They ground the stump down about 8 in below grade. My question is, who has the best/easiest solution (shy of hiring someone to do it) for removing all of the roots? Can it be done with a mini excavator? Any special attachments worth getting? What size excavator can handle it?

Use the Cruiser and pull on the root at a 90 degre angle if possible. Your yard is going to suffer no matter what.