For more than 20 years, Superior Walls have been installed on the same material: crushed stone. How can this be? Doesn’t the stone wash out from under the walls? Doesn’t the house settle? All are valid questions. Here are some answers:
Superior Walls are placed on stone for a few reasons. In order to achieve a level foundation, stone must be used. The Superior Walls Certified Installation Crew on site just prior to installing the wall panels levels the stone.
Stone allows for extra moisture under the foundation to flow freely into the drainage system. With a sub-footer of stone there is no place for the water to dam up and find its way inside the home.
Crushed stone transfers the load of the house structure as good or better than concrete to the virgin soil below. All houses are ultimately supported by the virgin soil, not the footer. Stone is used all the time as a footer material for such things as roadbeds and railroad tracks. The recently moved Cape Hatteras Lighthouse was moved on stone. Even the Pyramids were built on crushed stone. Frank Lloyd Wright used stone footers under some of his works of art.
When an engineer says that you have “bad soil” and you need to remove it in order to build a house, what does he tell you to replace the bad soil with? Crushed stone! Crushed stone replaces poor soils on virtually every building site.
The load of a house placed on a Superior Walls foundation is distributed similarly to the load of a train on a railroad track. A train exerts about 26,000 pounds per square foot on the track, while a house exerts around 3,000 pounds per square foot. If stone can hold the load of a moving train, then crushed stone can certainly hold the load of a house!
The stone under a Superior Walls foundation cannot “wash away” because the stone is kept in place by backfill and the concrete floor slab.
The bottom line is that crushed stone can be used under just about any structure. Stone is also less expensive than traditional concrete footers, and will continue to be used as a resourceful and efficient means to Better Building.