Beneath the decks of parking garages or city plazas are expansive waterproofing membranes. When improperly installed, extensive excavation for repairs incurs a heavy toll on building owners.

Sound guidance for the application of hot-applied waterproofing systems is provided in ASTM D 6622, Standard Guide for Application of Fully Adhered Hot-Applied Reinforced Waterproofing Systems. New in March, it includes material basics and installation techniques for:

• Built-up coal tar pitch and asphalt;
• SBS plies (Styrene-butadiene-styrene modified asphalt); and
• Polymer-modified (rubberized) asphalt.

“It is a single resource for a wide range of products,” said James C. Strong, Wiss Janney Elstner Associates, Inc., Emeryville, Calif., who chaired the ASTM group that developed the guide. “Generally, there is an unacceptable rate of failure in waterproofing systems,” said Strong, a senior construction specialist with 20 years experience in roofing and waterproofing technology. “The price of failure is very high. Once topping slabs or landscaping is installed, it’s very difficult to locate a leak, so you end up tearing out large areas that are quite expensive to remove and replace.”

Hot-applied waterproofing beneath low-slope (plaza deck) surfaces are typically finished with stone pavers, concrete slabs, planters, and trees. Beneath the finished surface, the waterproofing membrane protects interior spaces below and structural materials from water damage.

“When it does fail, it’s very problematic because it’s so expensive for owners to fix,” noted Strong. “Because they’re buried, essentially there is no way to maintain them. What gets installed needs to work and keep working for a very long time.”

Strong drafted the standard in 1977 with a small resource group in Subcommittee D08.22 on Waterproofing and Dampproofing Systems. Subsequent drafts were reviewed by members of ASTM Committee D08 on Roofing, Waterproofing, and Bituminous Materials, who represent a cross-section of consultants, manufacturers, contractors, trade institutions and government agencies. Canadian standards for rubberized asphalt were incorporated into D 6622 at the suggestion of D08 members who work in Canada.

A 1985 companion document on the design of built-up waterproofing, ASTM C 981, Standard Guide for Design of Built-Up Bituminous Membrane Waterproofing Systems for Building Decks is being revised by Subcommittee C24.80 on Building Deck Waterproofing Systems, part of Committee C24 on Building Seals and Sealants.

For further technical information, contact James C. Strong, Wiss Janney Elstner Associates, Inc., Emeryville, Calif. (phone: 510/428-2907). Committee D08 meets Dec. 2-5 in Dallas, Texas. For meeting or membership details, contact Staff Manager Pat Picariello, ASTM (phone: 610/ 832-9720). //

Copyright 2001, ASTM