
Washington
Space Needle
Waterproofing and resurfacing the observation deck of an iconic landmark while remaining open for visitors.
-
Category
Waterproofing & Deck Coating Solutions -
Completed
2018 -
Type
Hospitality & Entertainment -
Size
29 squares
Challenge
Updating and preserving the 57-year-old Space Needle’s
observation deck meant more than just resurfacing — it required
a system that could handle structural movement from wind
and temperature, perform in Seattle’s rainy climate, and allow
it to remain open to the public throughout the duration of the
renovation. Therefore, the solution needed to meet the project’s
aesthetic, structural, and scheduling demands all at once.
Solution
A Siplast liquid-applied PMMA system was applied to deliver high-performance waterproofing and surface protection, while a quick cure time allowed the Space Needle to stay open for visitors:
- Fast-cure application for minimal visitor interruption
The Terapro Waterproofing and Surfacing System cured quickly, even in Seattle's damp conditions, which enabled application to proceed without weather delays and allowed for a swift return to full visitor service. - Durability for high-traffic surfaces
A Pro Natural Quartz aggregate finish created a hard-wearing surfacing layer to protect against the observation deck's high level of foot traffic. - Flexible, reinforced waterproofing system
Layers of catalyzed PMMA resin with fleece reinforcement built up a high-mil, UV- and abrasion-resistant barrier to help withstand movement and protect against wear due to pedestrian traffic and environmental exposure*.
Thanks to its phased installation and Terapro's rapid cure times, the project was completed without closing for visitors. The result was the preservation and long-term protection of a world-class structure and visitor experience.
* See sample Siplast guarantee(s) for complete coverage and restrictions.
Siplast Systems
Image Gallery
Click on an image below to see a larger version
Have questions? We have answers. Find a Representative

Terapro Waterproofing & Surfacing Systems
In the 1930s when polymethyl methacrylate resins, commonly known as PMMA, were first synthesized. Practical applications for the new resin, which included everything from aircraft windshields to dentures, soon followed. The material proved to be exceptionally durable, and the use of PMMA grew rapidly. But in spite of its outstanding performance, the material was too rigid for use in waterproofing applications - until the 1970s. Learn more about our brand of Terapro Waterproofing & Surfacing Systems, our history, and our dedication to innovation.