Voids can be created under concrete in a number ways.  Animals may burrow, water runoff can create erosion, soil shrinkage, leaky plumbing, and tree roots are just some of the ways.  Left untreated, voids can grow and cause the concrete above to crack.  It can be nearly impossible to backfill a void with soil and compact it sufficiently to provide support.  And backfill soil has a high risk of future erosion. Secure Set Spray Foam solves this problem easily. 

Visible and Hidden Voids

Secure Set Spray Foam can be used to easily fill both visible and hidden voids.  Once filled, the concrete slab is fully supported and the potential for future erosion has be reduced to almost zero.  This is because Secure Set is both inert, significantly more dense than soil, and it adheres to itself to form a single layer. 

Filling Visible Voids

In situations where the void can be accessed, either through minor excavation, or because the soil around it has washed away, Secure Set Spray Foam can be used to fill the void by direct spraying.  Starting at the furthest point from the edge, begin spraying the foam in short bursts, allowing it to expand. Then continue to build on each layer working your way back to the edge.  New foam will adhere to hardened foam, creating a single solid layer. 

Filling Hidden Voids

If the void is hidden, you will need to drill holes in the concrete that allow you to inject the Secure Set into the void. 

Spray Foam

A homeowner uses Secure Set Spray Foam to fill a void under a walkway that was created by water runoff.  Secure Set will not only support the walkway, it will prevent further erosion.

Watch the videos on this page to see how homeowners use Secure Set Spray foam to fill open, extended and hidden voids.

Videos showing how to use Secure Set Spray Foam

The videos below demonstrate cases where Secure Set Spray Foam was used to fill different voids.  We encourage you to watch each as there are similarities and some unique elements to each project which can apply to many other projects as well.

Filling a Void Under a Patio with Secure Set Spray Foam
Repairing Washouts and Extended Voids with Secure Set Spray Foam
Filling Voids Under Concrete and Flagstone with Secure Set Spray Foam
How to Set Up Nozzle and Extension Tubes for Extended Reach
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DIY Void Filling with Secure Set

Our customers do their research and often compare bids from contractors to rip out and replace a concrete slab or level it with other methods before deciding to use Secure Set on their own. 

Two things stand out as factors in choosing to do it themselves: 

  1. Cost – Using Secure Set often saves them several thousands of dollars.
  2. Time –  removing and replacing a slab takes time and renders the area unusable for several days while the concrete cures.

With Secure Set Spray Foam there is no need to remove concrete, backfill and compact the soil, and then replace the concrete.  Even hard to reach or hidden voids can be filled with Secure Set. 


Here’s what Anthony F. told us about his experience with Secure Set Spray Foam

“We ended up purchasing and using 4 of these kits with a concrete slab terra jack with a low profile 20-ton jack. Worked perfectly for us and completed lifting our pool decking which sunk over last 20 years. Ended up saving us thousands of dollars doing it in house and instead of outsourcing it to another party, for poly raising or concrete replacement.”

Downloadable Guides

Secure Set Spray Foam Instructions

Secure Set
Spray Foam Instructions

This is an instruction set you will definitely want to read to make your project a success.
Secure Set Spray Foam Temperature Guide

Secure Set
Spray Foam Temperature Guide

There is an ideal temperature range to get the best results from Secure Set Spray Foam. This applies to product temperature and the ambient temperature.
How to Use Extension Tubes with  Secure Set Spray Foam

How to Use Extension Tubes with  Secure Set Spray Foam

Five steps to create extension tubes to reach deep voids. 
Using extensions tubes can decrease the yield of the product. Testing with a 50' extension significantly reduced the volume of foam and increased the density. Even 10' extensions have been found to reduce the yield. It is difficult to estimate the reduced yield due to variables including product, ground, and ambient temperatures.
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