How to Dig Under a Garage

Set up a vacuum excavator according to the equipment's instructions. Mount the vacuum excavator's large, tank end to the tailgate of a truck in such a way that the tank's contents will simply fall into the truck's bed. Place the excavator's hose end under your garage.

Shovel onto a screen soil and rocks from the places you want to enlarge under your garage. Remove by hand large rocks that do not pass through the screen. Such large materials could clog the vacuum excavator and delay your efforts.

Turn on the vacuum excavator, and use its nozzle end to vacuum the shoveled soil and small rocks from under your garage. The process is not much different from using a shop vacuum cleaner; it's just on a far larger scale. All of the material will end up in the truck bed, ready for transport.

Place wooden piling blocks in the spaces that shoveling and vacuuming create on top of the existing pilings and in places where you want a little extra support. Do that task for every few feet of space you create by shoveling and vacuuming. Crisscross each level of pilings. For example, make one level of wooden piling blocks parallel to your body when you are in front of the supporting wall, and make the next level perpendicular to your body. When that crisscross technique is used, a particular piling block that shifts will not fall out of place and take the rest of the wall with it.

Remove the vacuum excavator's tank end from the truck when the truck's bed is full. Drive the truck to your disposal site, and shovel the soil and rocks out of the bed.

Repeat the steps as necessary until you remove all that you want to remove from under the garage.