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Why Your Garage Floor Is Sinking & What To Do About It

Sinking Garage Floor – Causes

As with most slab settling issues, voids and poor soil compaction are at the root of the problem. This is certainly the case with sunken garage slabs. They are typically constructed by backfilling the area after the foundation is poured (or blocked) and pouring the concrete on top. Achieving proper and adequate compaction is often difficult and just not achieved in many cases. This, combined with time and freeze/thaw cycles creates voids under the garage slab. Concrete itself is heavy and can settle, but when we park vehicles on top of a garage slab that has voids under it? It is obviously a recipe for disaster!

Sinking Garage Floor – Solution

Call LevelRite for a thorough site evaluation. We’ll take the time to properly inspect the issue, which generally entails probing the slab to determine if there is indeed a void and/or unstable soil (and to what extent). Gathering this type of information is key to designing a proper repair plan and calculating the material amount.

Depending on the conditions found during site evaluation, there are a couple of different techniques we use (and oftentimes both). If the soil under the garage slab is soft and unstable to a certain depth, LevelRite will opt for the Deep Lift® method using Alchemy-Spetec‘s high-density polyurethane. The expanding structural foam creates a squeeze effect in the loose soil, essentially forming added support footings under the slab. Our other injection method, Slab Lifting, entails going through ⅜ inch holes drilled directly through the slab. The same structural foam described above is used. The expanding foam travels the path of least resistance, therefore, filling all void areas as well as compacting any loose soil. Once the soil is compact, the expansion of the foam creates the power to lift the slab. Our high-density polyurethane cures to 90% in fifteen minutes – which translates to the slab being traffic-ready by the time we are packing up our equipment.

Eliminating Trip Hazards

Sunken Slabs Create Trip Hazards

One of the first reasons a sunken slab is often noticed is because it’s created a trip hazard. The Americans with Disabilities Act (ADA) defines a “trip hazard” as any vertical change over a ¼ inch or more at any joint or crack. Cities, school districts, hospitals, churches, shopping malls, universities, apartment complexes, homeowner associations, large buildings, and private residences should all be concerned with this liability.

Concrete Leveling with Polyurethane

Eliminating these hazards and avoiding litigation is as simple as hiring a contractor who is using the right concrete leveling technique and material. Ground Consolidation Services lifts and levels slabs using Alchemy-Spetec’s line of AP Lift products. These high-density polyurethane lifting foams are used in a wide array of applications from lifting walkways to lifting highway bridge approach slabs on DOT projects.

Slab Lifting vs Slab Replacement

In addition, LevelRite has specialized tools in our bag like the jack system we use to mechanically manipulate the smaller, harder-to-control slabs. The only other viable option to lifting the slabs, in most cases, is the removal and replacement of them. This option is generally much more expensive and certainly more time-consuming and intrusive. We often do jobs for customers who have gone that route in the past and every single time they say they wish they had known that LevelRite was an option. We are usually done within a few hours, with the treated areas being traffic ready immediately.