Problems With Applying Fill Against Stucco When Applied to EPS Foam Over a Concrete Foundation

Filling Issues

• During the filling process, your insulation and siding can suffer accidental damage. If you plan on using heavy equipment to pour your fill dirt, take care not to hit the siding with your shovels or earth-moving machines. Make sure that you always pour dirt into the spaces beside your foundation walls from above. Pushing dirt into the trench can damage the siding, and it also puts additional stress on your foundation walls. In some cases, the additional stress can cause your concrete foundation to crack.

Infestation

• Buried foam insulation can allow termites, ants and other burrowing insects to infiltrate the structure of your home. You can prevent burrowing insects from damaging your insulation using EPS foam treated with borax or another form of pesticide. You can also install plastic sheeting over the insulation to create a barrier between the insulation and the ground.

Water Damage

• Insulation and stucco installed beneath ground level can trap ground water against the walls of your foundation. Water that penetrates the stucco and insulation will become trapped against the wall behind them. The insulation will prevent the water from evaporating and, over time, this water permeates through your foundation walls. Installing a well-sealed layer of plastic sheeting over the insulation will help prevent this problem and insect infestations. Look for EPS insulation that has indented channels on one side that will drain water that does get trapped behind the insulation. Applying a coat of concrete sealer to your foundation walls will further reduce the chances that water will penetrate your basement through your external sheathing materials.

Considerations

• When you refill the spaces around your foundation walls, apply fill dirt evenly throughout the trenches in layers. This will limit the amount of stress on your walls and decrease the probability of damage to your stucco and insulation sheathing during the filling process. If the soil around your home has a high concentration of clay, consider adding a layer of gravel to promote proper drainage in the soil around your foundation. Installing drainage lines around the perimeter of your home during the filling process will also help prevent water damage. Install drainage lines at or below the bottom of your stucco and EPS foam sheathing.