Methods

Wet holes

We specialize in digging “wet holes” in sandy or unstable soils with high water tables, using Super Mud, a polymer for creating a slurry to stabilize foundation holes.

Clamshells

Bost Construction uses a clamshell method for digging foundations. Our clam shell buckets are round and come in many different sizes. We can dig holes 18 inches to 12 feet in diameter and up to 80 feet deep with this method. Our equipment consists of an excavator style machine, to which we attach our clam shell. For foundations over 25’ deep we have a telescopic boom which attaches to the end of the excavator. Clam shelling is much more environmentally friendly because we can load our spoils directly into a dump truck or open container. The spoils of augured holes are typically spun on the ground, then cleaned up after the drilling rig is moved out of the way. 

Stabilizing

We use several different methods for stabilizing the side walls of our foundation holes. The first method and most widely used is creating a slurry. An environmentally safe polymer called Super Mud is mixed with fresh water to create the slurry. As material is removed the slurry is added and the thick viscosity of the liquid keeps the sidewalls from collapsing. When the hole is dug to its specified depth, the rebar cage is installed, a tremie pipe is inserted to the bottom of the hole, and concrete is poured through the tremie pipe. As the concrete fills the hole, the slurry is pumped back into the water trucks.

Caisson

In some instances, the ground is too unstable for the Super Mud to hold the side walls. If this happens, steel pipes (caissons) are inserted into the holes to keep them from caving. These caissons are removed as the concrete fills the hole. In some severe instances the caisson must be left in place. A removable form is fitted at the top of the foundation to allow for a smooth exposed finish.