Basement Construction
for Your Small House

You have just completed installation of the footers and you are now ready to begin constructing the walls of the basement for your new small house. The footers have been set to exceed the thickness of the basement walls with all reinforcement rods in place.

The next step is setting the forms that will mold the concrete for the basement walls. The forms generally consist of metal panels that are attached via a metal sill plate that is attached to the footers. If you are planning a full basement the height of the walls is typically 8 feet to allow enough space if you plan to use the basement as a family area in the future. The thickness of the walls will depend upon the type of materials you are using for the structure that will rest on the basement walls. For instance, brick will require thicker basement walls than a wood structure.

As a general rule, the forms that are placed on the outside of the footer are installed first. This allows ample space to install the reinforcement rod infrastructure in addition to the reinforcement rods that have already been installed with the footers.

The amount of reinforcement rods you will need depends upon the building code for your region and the topography of your land parcel. If your small house is being built into a hillside you will want to increase the amount of reinforcement rods to support the pressure of the hillside that is pushing against that side of the basement wall.

Once the reinforcement rods are in place, the second set of forms is constructed through attachment to the inside anchors on the sill plate of the footers. The forms also contain attachments at the midpoint of each panel as well as the top. Once the panels are connected and properly attached to the footer the pouring of the concrete can commence.

Before you begin to pour concrete you want to consider your options for basement insulation. Basement insulation is accomplished through the use of a material known as polystyrene. Polystyrene is non-porous foam that is applied below the level of the backfill point. This can be applied to the exterior of the concrete wall after the concrete has been poured or it can be placed inside the concrete forms before pouring the concrete. The concrete adheres well to polystyrene and either method is effective as long as the insulation is at least two inches thick.

One advantage of installing the polystyrene insulation inside the forms before pouring the concrete is that this will allow you to additionally apply sealant and waterproofing to the outside of the foundation once the concrete has cured and the forms have been removed. If you opt to place the insulation on the outer wall after the forms have been removed, be sure to seal it from damage with a mortar mix or other type of foundation sealant.

Another factor to consider in small house basement construction is foundation drainage. This requires the installation of gravel and drain tile around the footers of the foundation. Drain tile is a porous piping that catches excess water from the groundwater table. It is placed in a ditch of gravel that slopes slightly away from the foundation and is connected with an underground drainage pipe which slopes away from the house. The underground drainage pipe in turn drains the water into another source such as a road ditch or something similar that is positioned within a significant distance from the house.

If you implement all of these steps when constructing a basement for your small house, it will mean fewer headaches in the life of the structure for years to come.

Other Resources on Basement Construction

The University of Missouri Extension has a nice publication on basement construction with concrete. Some great information. Even includes a nice cross-sectional diagram of a foundation wall.

The Concrete Network offers an 11 point checklist for basement construction.

Pictures From Our Basement Construction

The forms for the walls are up and filled with concrete, waiting to set.









The area right in front on the basement windows had a little more dirt removed to allow for a future "window well".


Now the concrete forms have been taken off, the exterior of the walls waterproofed, and the ridgid foam insulation applied. Notice the clean gravel now on top of the drainage tile around the perimenter.