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 compaction grouting used for general soil densification, void filling targets a specific, already-identified cavity rather than treating a broad zone of loose soil.
In Austin, those voids most often trace back to dissolution features in the Edwards Limestone or, closer to downtown, cavities in the Austin Chalk that formed over geologic time and are now being exposed by groundwater flow changes from development. GSI's Austin 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.
We use ground-penetrating radar and test borings to map subsurface cavities, which is common practice on Austin sites known to sit over karst limestone.
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 karst features can still develop independently over time.
A subsurface void in Austin's karst limestone stays hidden until it isn't. Call (855) 599-5217 to get an Austin void filling assessment from a licensed engineer.
