Recently I have become aware of the practice of substituting urethane foam for piles in foundation repair. Are they equal? Can one be substituted for the other?
Helical and push piles offer the advantage driving to a deep loadbearing strata for support and attach mechanically to a point loaded footing with brackets specifically designed to accommodate those loads. Although piles can be used to raise and stabilize slabs and paving, I don’t think they are ideally suited for that because of the inability of the slab to span between piles effectively. For those situations either mud jacking or urethane foam grouting is usually a more suitable repair technique.
Urethane foam does offer some advantages as a mud jacking technique balanced with its costs, which typically can cost a little more. Mud jacking or foam injection by definition does not improve the soil conditions that support loads. So unless the foam is improving the soil at a deep level it will not be effective in permanently stabilizing foundations.
So can urethane foam improve soil conditions at deep levels? I argue persuasively in my previous blog grouting smoke and mirrors part two that it does not.
No third-party testing data has shown conclusive proof of deep soil densification with injection of urethane foams. In my blog cited above I actually show evidence of the opposite.
While urethane foam does offer cheaper costs than piles for foundation stabilization it does not offer a solution comparable in performance and should not be used as a substitute.