Most projects complete in a few days to about a week depending on the void's size and how many injection points the design requires.
Void filling injects grout, typically a low-mobility compaction grout or an expanding polyurethane, directly into a confirmed subsurface cavity to displace water and air and restore structural support to the ground above it. Unlike broad-area compaction grouting, void filling targets a specific, already-identified cavity rather than treating general soil weakness.
In San Antonio, those voids trace back to two overlapping causes: natural dissolution along the fractured Edwards Limestone of the Balcones Fault Zone, and infrastructure-driven raveling where leaking utility lines have washed fines into those same fractures. GSI's San Antonio void filling work typically includes:
Most projects complete in a few days to about a week depending on the void's size and how many injection points the design requires.
Cost depends on void size, depth, and grout type, which we confirm with subsurface investigation before providing a fixed-cost proposal.
Void filling addresses a cavity before it has collapsed at the surface. Sinkhole repair addresses a void after the ground above it has already given way.
GSI offers 24/7 emergency response and can mobilize a crew within hours if a void is discovered beneath an occupied structure or active roadway.
Yes. Aging water and sewer lines that leak slowly can wash fine soil into fractures in the underlying limestone, gradually forming a void even without any natural karst dissolution.
Yes. We select grout materials and injection methods that meet Recharge Zone environmental requirements when work occurs within its boundary.
Yes, that's its primary purpose. Filling a confirmed cavity before it collapses is generally less disruptive and less costly than repairing a sinkhole after the fact.
A properly engineered void fill restores structural support to the treated area permanently, though nearby untreated fault-zone features can still develop independently over time.
A subsurface void along San Antonio's fault zone stays hidden until it isn't. Call (855) 599-5217 to get a San Antonio void filling assessment from a licensed engineer.
