PENNTROWEL 250 Epoxy Underlayment is a high performance silica-filled epoxy based underlayment. It has been formulated with the most up-to-date resin technology to withstand high temperatures and thermal cycling. It exhibits excellent chemical, abrasion, and impact resistance. PENNTROWEL 250 Epoxy Underlayment is specifically designed for use in wet areas that are difficult to keep dry during installation. It may be applied over damp concrete or placed into areas with standing water. The installed, cured underlayment exhibits excellent physical properties and adhesion.PENNTROWEL 250 Epoxy Underlayment can be applied in a wide variety of thicknesses. When resurfacing exceeds two inches, up to 25% pea gravel may be added. Peagravel or other aggregates must be dry and free of salt and other contaminants. Consult Corrosion Engineering specification CES-232 for complete installation details.