How to Fill Voids in EPS Foam

Polystyrene has a lot of uses on a construction site.

EPS foam stands for expanded polystyrene, and while it sounds like something you would use for a cooler, the material is actually used in construction. However, this material can support a great deal of weight, and it can be custom-sized to fill the voided areas that you need. Often used for handicap ramps, movie theaters and amphitheater construction, these EPS foam voids are easy to use and make great fill.

Things You'll Need

• EPS foam voids
• Tie bands
• Blueprint
• Shovel/Digging equipment (optional)
• Tamper, mechanical or manual (optional)

Instructions

1. Clear the space that you need for your foundation of the project according to your blueprint. Dig the foundation hole if that's necessary, and tamp the soil to be sure that it's as compacted as possible. EPS foam voids are blocks that are meant to be used as fill, support or both when holding up the base of the construction project. As such, you need to have a firm base for the blocks to rest on, like concrete or heavily packed dirt.

2. Put the blocks in place. These blocks typically come in 3-foot-by-4-foot-by-8-foot cubes, though you can order them according to the size specifications you need for your project. The blocks weigh a fraction of blocks of an equal size made of another material would, so you can put the blocks in place by hand.

3. Settle the blocks in place. You can tie the blocks together using metal ties specifically meant for use with EPS blocks, but other methods like cement or construction adhesive are also ways to permanently attach the blocks in place. Keep in mind that if the blocks are only temporary, you don't want to use methods that can't be easily removed later. For example, a foam void might be put in place to support an arch while you pour concrete, but after the concrete is dried the arch can easily support itself, and the block needs to be removed.

Tips & Warnings

• Make sure that the blocks you have are meant to support the weight of the project for which you're using them. Using the blocks to create a basic handicap ramp is one thing, but using them to support a large stage covered in actors and scenery, or to support a bridge, is something else entirely. Always check and double-check the weight bearing measurements.

References

• Pro Wall: Void and Fill Foam
• Universal Construction Foam: Earthwork Void Fill Foam