4′ x 8′ sheets used under an in-floor heat system can be cut to any required thickness.

Benchhmark Foam has been cutting and shaping expanded polystyrene (EPS) in innovative ways since its birth into the industry in 1988. Perhaps the most traditional, yet versatile way is in the form of 4′ x 8′ high density insulation sheets. These EPS sheets are commonly found under in-floor heat systems and perimeter insulation.

As an alternative to blue, pink or yellow extruded polystyrene (XPS), EPS is an ideal insulation for sub-slab applications such as in-floor heat systems for several reasons, including its strong bond with concrete. When staples are used to secure pex tubing for in-floor heat, EPS holds a better grip than competitor sheets, resulting in a more stable system once concrete is poured. EPS sheets are also more forgiving when the backfill dirtwork is unlevel. Even small mounds and valleys in the backfill can cause other insulating sheets, such as XPS, to literally crack under pressure. Benchmark Foam’s EPS sheets maintain the flexibility to adjust to less than perfect backfill, a quality that XPS cannot match.

An example of 4′ x 8′ EPS sheets being used for perimeter insulation.

While EPS and XPS maintain similar physical properties, such as compressive strength and variable densities, one characteristic sets them apart today – cost.  A high density 4′ x 8′ sheet of EPS will cost the average end-user around 69 cents per square foot.  The same size sheet of XPS will cost the end-user at least 10 cents more per square foot – and depending on the size of the job, the savings of choosing EPS over XPS can be significant.

Next time you’re looking for a cost-effective and durable rigid insulation board, learn how Benchmark Foam’s high quality products can meet all your expectations.  For more information on high density 4′ x 8′ sheets and similar products, contact us at 800-658-3444 or 605-886-8084.