How Thick Do Concrete Walls Need To Be Underground

For flatwork such as slabs on grade and driveways a minimum thickness of four inches is required but increasing the thickness to five inches can add nearly 50 percent to the load bearing capacity.

How thick do concrete walls need to be underground.

A good rule of thumb is to have a minimum of about 3 0 3 5 cubic yards of concrete mass to serve as your safe room base. As soon as you go higher or have greater depths of soil pushing against the wall you need to increase the thickness to 10 inches. When a taller wall or a higher level of soil or both come into play the thickness should increase to 10 inches. Disadvantages of underground homes.

The slab can be a square or rectangular so long as the minimum depth and surface area requirements are met. Precast walls in order for a concrete room to effectively resist high winds and flying debris most rooms built with precast concrete walls rely on 12 to 16 inch thick blocks. These basement walls are subjected to different forces and loads which will require standard design and construction practice to achieve the desired quality. For a 4 thick slab this equates to about 250 300 sq ft of surface area.

The block wall is built with rebar and all services in place. Understanding the basic requirements of underground or basement wall construction helps to attain durable basement walls with minimum maintenance. Any plumbing or electrical service must be in place and tested before the concrete is poured into the forms. Thickening the structure along the perimeter by another will serve as an integral footing adding strength where the loads are heaviest.

As an alternative concrete blocks are often used. This could cause condensation issues within the walls and other areas of the home. In general poured concrete basement walls that are 8 feet tall or less and have no more than 7 feet of soil pressing against them from the outside function well at a thickness of 8 inches. In general for a one story building the walls would be at least 12 inches thick.

Condensation issues humidity levels are generally higher in underground homes. To keep the house and the room from being sucked into the air during a tornado large footings that work like anchors are added to the walls to hold the room in place. Poured concrete foundation walls that are less than 8 feet tall and have soil outside that is 6 or 7 feet deep against the wall can often be 8 inches thick and function quite well.