How A Stump Grinder Works
A grinder chews a stump down to chips using a rotating wheel fitted with hardened teeth, working from the top and both sides until the stump sits at or below ground level.
Chips stay in the hole unless you would rather they were hauled off entirely. Most customers use them to backfill the hole and top it with soil.
Depth Depends On What Comes Next
How deep we grind depends on what that patch of ground becomes afterward, and we settle it in writing beforehand:
- Under lawn, six to eight inches down is plenty, since grass roots barely go deeper than that - Under a garden bed, deeper is better so a new plant sits in real soil rather than a bed of chips - Under a patio, a shed pad or a fence line, we go deeper again and usually have to trace the surface roots outward to cut them clear - If the goal is just clearing the mower path, a shallower and cheaper grind covers it
Sarnia's Clay Ground Settles More Than Sand
Once we finish, the mix of chips and soil settles over the following year, more noticeably here than it would on sandy ground, so expect to add another layer of soil at least once.
For this reason we leave the fill mounded a little higher than the surrounding grade. A depression that forms later collects water instead of letting it drain away, and heavy clay is already slow to drain on its own.
What Makes A Grinding Job Take Longer
A few things shift the price, and mentioning them up front saves a surprise later:
- Buried lines, since a grinder meeting a pipe or cable at speed is a real risk, and older Sarnia streets do not always match what the utility drawings show - Gate and fence-line width, since one of our machines fits through a regular gate opening and the other does not - Old wire or buried stone inside the stump, which can wreck a full set of teeth on one pass