Earth augers are not readily available for hire in many areas. Also, hiring an auger to drill only one or two holes can be expensive because operators may charge a full daily rate regardless of the project's size. Additionally, an auger is not equipped to load the soil it extracts from drilled holes. Thus, if you're working on a paved surface, you must shovel up the soil and remove it from the site. These factors make auger-drilled sign foundations impractical for many projects.
Vertical slabs are the most widely used and practical design for sign footers.
The shape of this footer conforms to the digging stroke of a backhoe machine. Because backhoes are towed on trailers behind dump trucks, the contractor can remove all soil from the job site. For any given freestanding sign structure, the horizontal-slab footer requires considerably more concrete to provide equivalent structural strength. But this shallow design might be necessary when installers encounter subsurface rock, groundwater or other obstructions. Sign companies should include language in their project contracts that allows for additional expenses necessary to install this type of footer.