Product #408-Polyurethane Waterproofing
Product #408 Polyurethane Waterpoofing Product #408

Elastomeric Membrane Waterproofing System- Coal Tar-Free


 A black, liquid applied, single-component, moisture-cured 100% solids, polyurethane waterproof coating, designed to form a low odor, seamless, flexible rubber membrane impervious to moisture.

Composition: Polyurethane elastomeric membrane.

  • Basic Uses: Once cured, EPOXY.COM PRODUCT #408 allows expansion and contraction over a broad temperature range and maintains waterproofing properties under continuous exposure to water. EPOXY.COM PRODUCT #408 remains flexible from –75 degrees F to +175 degrees F (-59 degrees C to 79 degrees C). EPOXY.COM PRODUCT #408 waterproof membrane is intended for use wherever overflow water must be contained.

    Suggested areas of application are as follows:

  • Waterproofing in between concrete slabs, such as parking decks, roof decks or courtyard areas over subterranean parking.
  • Waterproofing below grade exterior walls or foundations and basements or other structures that are to be backfilled.
  • Waterproofing inside planter boxes.
  • Waterproofing under terrazzo or tile floors.
  • Waterproofing under shower pans, kitchen, laundry and bathroom floors.
  • Waterproofing inside of elevated swimming pools.
  • Waterproofing of occupied areas under malls, plazas and promenades.
  • Water Tanks: EPOXY.COM PRODUCT #408 has been used with outstanding success as a lining for emergency water storage tanks. The EPOXY.COM PRODUCT #408 bridges hairline cracks and because of the materials flexibility, allows them to move with changes in temperature.

The product is fully bonded to the substrate so water cannot flow underneath the lining as it can with sheet lining materials.

Limitations: Containers that have been opened must be used within one or two days since it is a moisture-reactive material. It sets up when exposed to air. All surfaces must be completely free of foreign matter and dry.


  • EPOXY.COM PRODUCT #408 is a single-component compound that may be used directly from the container with no mixing required.
  • The addition of catalysts are not necessary, as EPOXY.COM PRODUCT #408 is a moisture-cured compound.
  • May be applied by spray equipment, brush, roller, squeegee or trowel, without the need for heating the material.
  • May be applied over concrete, stone, brick, cement blocks, wood, metal, asbestos and most other surfaces.
  • EPOXY.COM PRODUCT #408 cuts cost of application by eliminating mixing, splicing, sealing tapes, adhesives and other labor consuming methods required when installing other conventional types of waterproofing systems.
  • The superior flexibility and elongation properties of EPOXY.COM PRODUCT #408 allows expansion and contraction with the substrate, without cracking or becoming brittle.
  • Does not contain any potentially hazardous coal tar.

Color: Black only.
Standards: A.S.T.M. C836-89.

Before using the products, always refer to MSDS for important warnings and safety information. Use only in areas with adequate ventilation. Avoid breathing vapors. Keep away from heat and flame. Avoid contact with eyes and skin. In the event of skin contact, remove immediately and wash with warm, soapy water. Wear suitable eye protection. Always wash hands before eating.


EPOXY.COM PRODUCT #408 is best applied by airless spray. However, when the job does not lend itself to spraying, it may also be applied by roller, brush or squeegee.

All cracks over 1/16" (1.6mm) in width must be filled and covered with EPOXY.COM PRODUCT #372 a Knife grade version of this Product. This product may be applied by trowel or caulking gun. There is no need to wait for this product to cure before applying the EPOXY.COM PRODUCT #408 since they are completely compatible.

A dry film thickness of 60 mils (1.5mm) is recommended over concrete surfaces. Extremely porous substrates should be filled prior to coating or receive additional EPOXY.COM PRODUCT #408

Application must be made uniformly to avoid thin spots and care must be taken to avoid pinholes and repair them should they occur. Where a two coats application is preferred, allow a 24 hour cure time between coats.

Protection board must be used prior to backfilling or pouring the concrete topping slab.


Satisfactory results depend not only upon quality products but also upon factors beyond our control; methods of application and site conditions are examples of such factors and can affect product performance. This warranty consequently extends only to products installed in strict accordance with the manufacturer’s specifications. It is the users responsibility to satisfy himself, by his own information and tests, of the suitability of the product for his own intended use; user assumes all risk and liability resulting from his use of the product. The substrate to which the product is applied must be sound structurally and otherwise. Structural or substrate failures or imperfections resulting in damage to or failure of the product are not covered by this warranty. Since the use of the product is beyond the control of the manufacturer, the manufacturer assumes no liability for misapplication and misuse of the product.
This warranty does not cover consequential damages, nor does it cover the labor attendant to replacing product in the event of a product failure. The warranty only extends to replacement of the product itself.

All products proven to be defective in manufacture will be replaced at no charge. Since the use of these products is beyond our control we cannot assume any risk or liability for results obtained, nor can we accept damages in excess of the purchase price of these products.


If EPOXY.COM PRODUCT #408 is damaged, it can be repaired by cleaning the surface and recoating it with EPOXY.COM PRODUCT #408


All of the latest updates to product data and specifications are available at the Epoxy Systems, Inc. website at Since product data and specifications change, it is the user’s responsibility to make certain the most current versions of product data and specifications are being used.

For more information please contact: a division of
Epoxy Systems, Inc.
352-465-3497 (Fax)



Property Test Method   Results
Viscosity (poise) Brookfield  Viscometer 90 + 10 poise
Weight per Gallon   9.80 + 0.2 Pounds
Percent Solids ASTM D-2369 Weight 100.00%
Volume 100.00%
Tackfree Time at 77F (25C) and 55% R.H. 12-16 hrs.
Recoat Time at 77F (25C) and 55% R.H. 16-24 hrs
Hardness (Shore A ) ASTM D2280 15A
Tensile Strength (psi ) ASTM D412 300
Percent Elongation ASTM D-412 1400%
Water Vapor Transmission ASTM E-96 2.08 (grains/hr/ sq. ft)
(procedure B) water method
Adhesion to Concrete ASTM D-903 8 lb/in 1.5kg/cm)
no peel/film break
Hydrostatic Pressure Resistance ASTM D-751 94 psi
Resistance to Decay ASTM D-154 no surface defects
Flash Point   200 deg. F.
Recovery (percent) ASTM D-412 96%
Shelf Life 6 months (when stored indoors in a cool and dry location at 77F (25C) in unopened containers