You dont typically get a chance to see how Poly foam works under the concrete. In this video we get to experience the full expansion of the foam. Starting as a liquid it only takes 10-14 seconds to start expanding and tuning into foam. You can see how the foam will find ever nook and cranny, filling every void. It also compacts the soil for the best possible coverage. The foam will be completly hard and ready to drive on in 15 short minutes.