POST TENSION SLABS
Post - Tension vs. Concrete Slabs
We are building a new home and we want a post-tension slab. Is this something we should consider?
Post-tension vs. conventional concrete slab. Why? Concrete slabs rely on support from the soil below, and in Prescott and surrounding areas there are severely active expansive soils. These are soils that expand and contract due to moisture changes and the soils cannot provide the proper amount of support to the concrete slab and therefore foundation issues arise such as cracks, heaving and settling and major structural issues.
Post-tension slabs have steel cables built into the slab to reinforce the slab. Once the cables arte placed they are tightened to apply pressure to the sides of the slab. This allows the slab to support itself. Post tension slabs require more design and construction effort. A post tension design requires a significant amount of soil testing to identify the soil classification and plasticity index so that other design parameters can be developed. Building a post-tensioned slab does not stop the potential for post-construction movement; the movements are well minimized.