Building a shed in an area where a tree stump is located poses several challenges. While it is possible to build a structure over a tree stump, you do need to consider several factors before proceeding.
The Size of the Stump
Small stumps of several inches should not prove too difficult to remove with a spade and some elbow grease. A stump of 10 inches in diameter, on the other hand, will prove more difficult. In terms of depth, tree roots can descend 6 metres underground. Where diameter is concerned, the roots could easily stretch several metres in all directions.
For a larger stump then, you may find yourself digging and cutting for endless hours. A much simpler and faster option would be to hire a tree service to grind the stump out for you.
The Condition of the Stump
Is the stump still alive? If so, building over it is not an option—at least while it is still alive. Were you to build over it, its sprouts could damage the shed floor next spring. If you decide to build over it, you should first kill the stump to prevent future growth.
The fastest method of killing a tree stump, aside from stump grinding, is by using a chemical stump killer, such as Roundup. Within a few weeks, the stump and its roots will die. You can also try homemade remedies such as Epsom salts, the crystals of which, absorb moisture. However, homemade methods could require months to kill the stump.
Threat of Insect Infestation
Remember, just because you can't see the stump, that doesn't mean the same applies to insects. Wood-hungry pests like carpenter ants and termites, both of which are common in Australia, may later find the stump. These pests may then make their way into your shed or even your home.
The more the stump rots, the greater the chance that pests will sniff it out.
The After Effects of Removing the Stump
Once a you remove a tree stump, the ground begins to settle. The spaces that were once occupied by the stump and its root system cause the ground to slowly sink. You will need to prepare for this if you decide to hire someone to grind the stump out.
To ensure that the ground under your newly built shed doesn't gradually sink, use a fill material such as crushed stone to level out the ground.
In the case of large stumps that are still alive, the safest and fastest solution is to hire a tree service to grind them out of the ground. Otherwise, your project could be delayed by months.