TL-0019 — HYDRODUCT® 660 Drainage Composite for Horizontal Applications Technical Letter

HYDRODUCT® 660 was developed to eliminate the problem of choosing which drainage composite to use in projects with more than one type of overburden. HYDRODUCT® 660 Drainage Composite is recommended for all horizontal applications.

HYDRODUCT® 660 Drainage Composite combines the best attributes of GCP Applied Technologies (GCP) previous drainage composites. The high impact, creep resistant drainage core has a compressive strength of 21,000 lb/ft2 (1,000 kN/m2) and a drainage flow rate through the core of 16 gal/ min./ft (200 L/min./m). High strength, nonwoven filter fabric is uniquely designed to provide enhanced permittivity with superior resistance to damage on the jobsite. In addition it incorporates a backing film on the flat side of the core to protect sheet and fluid applied waterproofing systems.

HYDRODUCT® 660 Drainage Composite serves as both a drainage course and protection for BITUTHENE® and PROCOR® waterproofing membranes. As protection for these waterproofing membranes, drainage composites should be placed immediately following the installation of waterproofing membrane. In high wind or areas of heavy construction traffic it may be necessary to secure the drainage composite to the waterproofing membrane with PREPRUFE® Detail Tape or temporary ballast. Overburdens should be installed as soon as possible to prevent construction trade damage.

Insulated Decks

In insulated designs, drainage composite should be placed directly on waterproofing membrane and under insulation. While insulation manufacturers may recommend placement of insulation as close as possible to the structure, it is equally important and good design practice to provide drainage at the waterproofing membrane level. (Reference ASTM C 898 “Guide for use of High Solids Content, Cold Liquid Applied Elastomeric Waterproofing Membrane with Separate Wearing Course” and ASTM C 981 “Guide for Design of Built-Up Bituminous Membrane Waterproofing Systems for Building Decks”.)