Introduction

Soils

Pin Foundations, Inc. (PFI) has been designing and manufacturing foundations for over 25 years. One thing has always driven our thinking—the Earth is the actual foundation, and soils, in their natural undisturbed state, have the strength and structure to do the job.

Man-made foundations have two basic functions: to transfer loads properly into the Earth’s soil structure and to provide a connection to the built structure above. There are two general types of man-made foundations: deep vertical pilings (banged in) and shallow spread footings (dug in and buried). Pilings keep the Earth’s existing soil strength and structure intact, and are easy to install if they do not need to go too deep. Footings spread loads more widely, but the digging breaks apart the soil, weakening it and blocking or exaggerating water flow.

Pin Pile Technology

Pin pile technology combines the best features of both types of man-made foundations. By grouping short stiff piles (bearing pins), which can easily be driven into intact penetrable soils, and setting them at angles to work more like a shallow footing, a sound foundation can be constructed that requires no excavation. The pin pile group simulates nature’s design, resembling the roots of a tree providing bearing, uplift, and lateral capacity. In recent decades, grouped pin piling has become a reliable technology for complex, heavy-duty commercial applications, performing a superior job of transferring loads to intact undisturbed soils.

Diamond Pier Foundation System

PFI’s innovation is to bring pin pile technology into common use with a superior connector—the Diamond Pier concrete head. This high-strength, precast component is a driving guide, a pin piling lock, and a structural connection all in one. As a driving guide, the head maintains the pin angles so that their capacity is definable and consistent. As a lock, the head is designed to increase its grip on the pin cluster when loaded up, down, or sideways—getting stronger and tighter as loads increase. And as a connection, an embedded anchor bolt and precast, post-matching shape make it a simple and proportional complement to its supported structure.

This concrete head combined with the bearing pin group forms the Diamond Pier system—a hybrid of familiar concrete and steel materials. This system provides a solid, stable, economical foundation that both captures and preserves the supporting strength and natural functions of the Earth’s soil it's engaged in and, in turn, solidly and simply connects to and protects the permanent structures above.

This manual provides information and instructions for installing Diamond Pier foundations in residential applications in Normal Soil Conditions (see Conditions and Uses section).