How Thick Do Concrete Walls Need To Be Underground

These basement walls are subjected to different forces and loads which will require standard design and construction practice to achieve the desired quality.

How thick do concrete walls need to be underground.

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. 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. 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.

Condensation issues humidity levels are generally higher in underground homes. 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. 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. You ll need to consider incorporating more insulation to prevent condensation from intruding and eventually leading to mold and mildew issues.

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. 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. Any plumbing or electrical service must be in place and tested before the concrete is poured into the forms.

The block wall is built with rebar and all services in place. 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. In general for a one story building the walls would be at least 12 inches thick. The slab can be a square or rectangular so long as the minimum depth and surface area requirements are met.

For a 4 thick slab this equates to about 250 300 sq ft of surface area. The weight and pressure of the earth will obviously put an enormous strain on the walls and roof of an earth sheltered home which is why concrete makes an excellent choice for a building material. While poured concrete can work just fine for the foundation and the floor concrete blocks stacked and coated with a thin layer of fiber reinforced.