Foundation Excavation in Allentown, PA

Foundation excavation is the dig for a new basement, crawl space, slab or footing, plus the backfill once the walls are poured or laid. In Allentown and the rest of the Lehigh Valley, the main unknown is what sits a few feet down. The local Duffield soil has bedrock at 4 to 10 feet, and limestone weathers unevenly, so one corner of a basement can hit rock while the opposite corner is still in clay loam. We plan for that before the first bucket.

Sizing the hole

A foundation hole is larger than the house. Crews need room outside the walls to set forms, apply waterproofing and place drain tile, so we dig to the over-dig shown on the plan, slope or bench the sides for safety, and keep the bottom flat and undisturbed for footings. Spoil is stockpiled for backfill where the site has room, and the excess is hauled.

Rock and voids

If we reach rock, the options are to break it with a hydraulic hammer, adjust the floor elevation with the designer, or both. HomeGuide lists rock or ledge removal at $1,000 to $20,000 or more and notes that rock met during a foundation, basement or pool dig commonly adds $15,000 to $20,000 or more. On karst ground, a soft pocket or opening in the rock is a different problem; it goes to the engineer before anything is poured over it. Our quote states how rock is handled so the cost is not a surprise.

Additions on existing homes

An addition next to an older Allentown house means digging beside a foundation that may be stone or block and may sit on shallower footings than modern code. We dig next to it in sections where needed, avoid undermining the existing footing and protect the yard and driveway on the way in. Narrow city lots often mean a compact excavator and more truck trips, which we price in.

Backfill and drainage

After the walls cure and the waterproofing and footing drains are in, we backfill in lifts with suitable material and compact it, keeping stones off the wall face. The final grade pitches away from the new foundation. Poorly compacted backfill is the usual reason a patio, walk or stoop settles a few years after a new build.

Permits and inspections

New foundations need a building permit from the city, borough or township, and the footing excavation is typically inspected before concrete. We coordinate the dig with your builder and inspector so the hole is not left open longer than necessary.