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DOWSIL™ Case Study Cornish Commons – Seattle, Washington

Cornish Commons residence hall with unique rainscreen design - Seattle, WA
Cornish Commons residence hall with unique rainscreen design – Seattle, Washington (Used with permission: Casey Braunger / Ankrom Moisan Architects)

A premier college for the visual and performing arts, Cornish College of the Arts’ main campus is located in Seattle’s popular South Lake Union neighborhood, where the 20-story Cornish Commons opened in 2015.

The new residence hall and academic building includes a unique rainscreen design featuring 3/16-inch thick architectural aluminum cladding on cold-form framing. The innovative building design boasts thermal performance 40% better than required by current Seattle Building Code.

Cornish Commons’ Challenge

To achieve its ambitious thermal performance, the rainscreen design includes 2-inch, continuous R-8, exterior insulation to supplement the R-32 interior batt/cavity insulation. But that created additional challenges to be compliant with the Seattle Building Code, which dictates use of insulation outboard of the metal framing. The proposed design needed an air barrier with high permeability to ensure water vapor was not trapped in the wall cavity.

Additionally, staying on schedule – in spite of challenging Seattle weather conditions – was critical. Minimizing product incompatibility issues also was important.

Cornish Commons’ Solution

Ankrom Moisan Architects, Inc. selected the 100% silicone DOWSIL Silicone Air Barrier System to ensure enclosure airtightness performance, durability and compatibility.

When we learned about the option of a fluid-applied silicone air and water barrier, we realized that DOWSIL DefendAir 200 was ideal for our needs. Not only did the spray-applied product simplify installation and eliminate the need for traditional membrane materials, its high permeability ensured our design’s compliance with Seattle Building Code.

Eric Bressman, Architect, Ankrom Moisan Architects

Unitized Construction

To keep the Cornish Commons project on schedule, the design called for a combination of unitized rainscreen panels and traditional construction techniques. The use of unitized panels assembled off-site in a controlled manufacturing environment enabled continued productivity, regardless of weather.

An external cladding contractor’s licensed use of a patented, universal joint system (U.S. Patent 8,943,773) facilitated construction of the unitized panels. This system is designed with interlocking joints that mitigate improper installation conditions that increase the risk of failure.ß The joint system relies on DOWSIL sealants for enhanced performance.

The panels used DOWSIL silicones exclusively: DOWSIL DefendAir 200 as an air barrier and DOWSIL 791 Silicone Weatherproofing Sealant for unit sealing. The quick cure capability of the DOWSIL products helped keep unit assembly on schedule. The unitized rainscreen system was used from the third floor to the 20th floor – using 30 units per floor – with approximately 50,000 square feet protected by the DOWSIL Silicone Air Barrier System.

All-Weather Installation

Construction on-site continued into late fall, due in part to the low-temperature installation capability of DOWSIL DefendAir 200, which can be applied at temperatures as low as 20°F (-6°C).

The ability to use spray-applied product was much easier, said Jerry Jensen, Project Manager. Its cold-weather ability allowed us to continue construction into inclement fall weather.

In addition to the unitized rainscreen panels, on-site work totaling nearly 8,000 square feet used the DOWSIL Silicone Air Barrier System on the first and second floors.

Confidently Build A Better Barrier – Simple. Compatible. Silicones.

Because it is not uncommon to face challenges with varying interfacing construction materials, having a compatible all-silicone solution from Dow was appreciated and advantageous.

Having exclusively silicone products ensured compatibility. Rather than an ‘origami’ of incompatible materials around openings, having all-silicone materials simplified construction and eliminated uncertainty. It is straightforward. We can get answers from a single, trusted manufacturer, without unproductive back-and-forth exchanges with multiple suppliers. It’s helpful to have the continuity and support – and the confidence of warranty protection – from [Dow.]

Jerry Jensen, Project Manager, external cladding contractor

Additionally, the all-silicone compatibility of the DOWSIL Silicone Air Barrier System allowed materials to be applied in any order, eliminating sequencing delays and expenses.

Learn More About DOWSIL Silicone Air Barrier System

Dow High Performance Building solutions include proven and innovative materials for structural and protective glazing, weatherproofing, insulating glass, high-efficiency insulation, and window and door fabrication. Learn more about the DOWSIL Silicone Air Barrier System and other High Performance Building solutions from Dow.


Last Modified: January 9, 2021

Cold Weather Silicone Sealant Application

Building Construction and Cold Weather Silicone Sealant Application
Building Construction and Cold Weather Silicone Sealant Application

Architects, general contractors, and waterproofing contractors face a recurring question every Fall and Winter. Can we use our warm and hot weather silicone sealant for cold weather applications? Yes. Ease of installation, compatibility, and durability are key selection criteria.

It’s all about the chemistry. One-part silicone sealant use atmospheric moisture to assist the curing process. Cold weather decreases the availability of moisture in the air, thus extending sealant curing times. At the same time, cold weather increases the risk of adhesion failure, due to moisture or frost on the joint substrates. Clean, dry, and frost-free joints are one key to successful cold weather silicone sealant application. Ensuring sealant compatibility is another.

Randy McAdams, Senior Outside Sales, Atlas Supply

Cold Weather Sealant Application Glossary

  • Cold Weather Temperature: 5 ℉ above the dew point temperature, typically 40 ℉ or lower
  • Dew Point temperature: The temperature where air is unable to absorb any more moisture. Additional moisture falls as precipitation (rain, drizzle, fog) or condenses on cold surfaces (dew, frost), such as metal substrates.
  • Gunnable: The ability to apply sealant using a caulking gun with normal effort
  • Tooling: The act of shaping sealant already applied in an expansion joint using a caulk spatula to apply pressure and ensure adequate fill of the entire joint width.
  • Cure Inhibition: The result when a chemical, substance or environmental condition inhibits a sealant’s ability to cure properly. Tooling aides such as solvents can contribute to cure inhibition.
  • Silicone Rubber: Any of a class of synthetic materials which are polymers with a chemical structure based on chains of alternate silicon and oxygen atoms, with organic groups attached to the silicon atoms.

Cold Weather Silicone Sealant

Silicone sealant is durable, easy to apply and tool, able to adhere to most surfaces, available in multiple colors. All DOWSIL™ Silicone Building Construction Sealant remain pliable and easy to extrude (gunnable) in temperatures as low as -20 ℉. DOWSIL has 9 sealant rated for cold weather application:

  1. DOWSIL 790 Silicone Building Sealant
  2. DOWSIL 791 Silicone Weatherproofing Sealant
  3. DOWSIL 795 Silicone Building Sealant
  4. DOWSIL 995 Silicone Structural Sealant
  5. DOWSIL 756 SMS Building Sealant
  6. DOWSIL 758 Silicone Weather Barrier Sealant
  7. DOWSIL Contractors Weatherproofing Sealant
  8. DOWSIL Contractors Concrete Sealant
  9. DOWSIL 1199 Silicone Glazing Sealant.

What is sealant compatibility?

Sealant compatibility classifies sealant as chemically suitable or unsuitable to come in contact with other types of construction materials. These products may include weather resistive barriers (WRB), self-adhered membranes (SAM‘s), liquid applied membranes (LAMs) and building cladding. Silicone sealant are fully compatible with other silicone products. Conversely, non-silicone sealant will not adhere to silicone products. We strongly recommended pre-construction adhesion testing of all substrate coming in contact with the specified sealant.

Cold Weather Silicone Sealant Selection

Whether you select silicone sealant depends on the type of project and the climate where you live. Product specifiers and contractors in Western Washington and Oregon seem to gravitate towards silicone sealant because of their ability to adhere to a wide variety of substrates. Silicone sealant , silicone coatings and silicone waterproofing are more common west of the Cascade Mountains, due to the wetter, milder climate.

The Yakima-Tri-Cities Metropolitan Area located in southeastern Washington is one place that prefers silicone sealant. DOWSIL Contractors Weatherproofing Sealant and Contractors Concrete Sealant are competitively priced while still rated for application down to -20 ℉. These two characteristics alone help to explain their popularity.

Sign of Trouble During Cold Weather Silicone Sealant Application

Unseen moisture or frost on the substrate is a typical sign of trouble during cold weather sealant application. Moisture or frost on both porous and non-porous substrates can affect long term adhesion of any type of sealant. It is imperative that you Follow Manufactures Instructions for proper joint preparation in cold weather applications.

Signs of Trouble After Cold Weather Silicone Sealant Application

Adhesion Failure, Movement During Cure, and Adhesive / Cohesive Failure are all signs of trouble after cold weather silicone sealant application.

Adhesion Failure

Adhesion failure can occur for a variety of reasons including improper joint preparation and tooling. Incorrect joint geometry and cure inhibition are also causes for concern.

Movement During Cure

Joint deformation can occur when sealant are applied to cold substrate. Rising temperatures and expanding substrate cause uncured sealant to lose adhesion, wrinkle, or bulge, instead of remaining concaved.

Adhesive / Cohesive Failure

Adhesive failure occurs when a sealant fails to adhere (stick) to the substrate. Causes include dirty, moist, or frosty joint surfaces. Cohesive failure occurs when the sealant splits or tears within itself.

Consult a Cold Weather Silicone Sealant Expert

Cold weather sealant application comes with its own set of challenges, including longer curing times, sealant/joint conditioning, and maximum joint widths. Consulting a cold weather sealant specialist or waterproofing consultant helps you to specify and apply the right sealant. Call your local Atlas Supply silicone sealant specialist today at 1-800-347-5767. Get the help you need to maximize your success and minimize the chance of sealant application/curing failures detailed above.


Randy McAdams, Senior Outside Sales, Atlas Supply

Randy McAdams, Senior Outside Sales, Atlas Supply
Randy specializes in selling waterproofing products throughout the Pacific Northwest for new construction, renovation and commercial repair projects.

Last Modified: July 15, 2021

AIA Seattle – 2020 Honor Awards for Washington Architecture

AIA Seattle – 2020 Honor Awards Cityscape

Join AIA Seattle for the 2020 Honor Awards for Washington Architecture on Monday, November 16, 2020. This is a virtual event, and admission is free. Sponsored in part by Atlas Supply – Seattle.


6:30 PM – Virtual Lobby Opens

7:00 PM – Program Begins

8:00 PM – Program Ends.

AIA Seattle – 2020 Honor Awards

Learn More & RSVP

How to Use Albion’s B-Line Sausage Guns

Albion Engineering B12S20 20oz Sausage Gun with Accessories
Albion Engineering B12S20 20oz Sausage Gun with Accessories

Watch how to use Albion’s B-Line Sausage Guns (Video Transcript). Then learn more about the materials, tools and accessories required to operate safely and efficiently.

How to use Albion’s B-Line Sausage Guns Video Transcript

  • B12S20 20oz Sausage Gun w/smooth and efficient 12:1 ratio drive
  • Albion B-Line Sausage Guns come complete with 6 nozzles, spare sausage piston, steel ladder hook pull, and yellow bulk piston
  • Cut nozzle tip to desired opening
  • Unscrew front cap and pull back on rod
  • Load sausage pack/Chub into barrel
  • Clip front end of sausage pack
  • Place front cap over nozzle and screw on barrel
  • Ready to dispense
  • For tooling joint, consider using 258 series spatulas
  • Lightweight Aluminum Barrel
  • Rotating Barrel
  • Ladder Hook Pull
  • Comfortable Full-Size Handle
  • No Slip Double-Gripping Plates
  • Wear Adjustment Screw

Albion B-Line Sausage Guns Materials, Tools and Accessories – Shown

  • Backer Rod – Closed-cell, polyethylene foam, joint filler, 1/8 to 1-inch diameter
  • Razor Knife
  • Albion Engineering B12S20 20oz Sausage Gun – with smooth and efficient 12:1 ratio drive
  • Sausage pack of standard viscosity material – Expansion joint sealant
  • Scissors
  • Albion Engineering 258 Series Spatula.