What is it?
Definition – the pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. Hydrostatic pressure increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above. Hydro=water; Static=not moving
Where does it come from?
Hydrostatic pressure can be caused from: rain running off a roof and draining toward a house, a high water table and/or a faulty gutter system; sometimes it can also happen because of wind-whipped rain.
Hydrostatic pressure describes when water is actually being pushed through the concrete slab. It is actually a very rare problem, but the term has been used inadvertently to describe all water problems. Only the section of concrete that is below-grade can experience hydrostatic pressure.
Many concrete floors with hydrostatic pressure issues are not good candidates for secondary floor coverings. Carpet will remain damp and become musty or the glue that holds vinyl and other flooring options will let loose. What is the solution for such a problem?
Polished Concrete is the solution. When a floor is mechanically polished, there are no additional topical sealers or coverings that are inhibiting the moisture to come out of the slab thus allowing the floor to continue to breathe. Even though a densifier/hardener is applied to the slab, this sealer soaks into the concrete and the reaction takes place at a molecular level so this process doesn’t have any effect on the concrete slabs’ ability to mitigate moisture. In most cases, polished concrete is the only solution for a high rate of moisture through the slab, but it isn’t a bad thing. Take a look at the picture below that had hydrostatic pressure going on in the slab that we polished. They still look great and you’d never know that there was a major problem with this floor at one time.