Gasket System for Exterior Curtainwall Panels
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ISEAL EP (Exterior Panel) is a compressed fit extruded silicone gasket system developed specifically for panel technology. ISEAL EP is for above grade exterior wall panel conditions, it provides thermal protection, air & water infiltration protection, and is not susceptible to UV damage.

The system consists of extruded silicone gaskets that are adhered to the substrate/panels with silicone sealant. A proprietary ISEAL EP Exoskeletal 4-way splice is used at all four-way vertical-to-horizontal splices to ensure continuity of performance at splices.

Typical Vertical Joint

Typical Horizontal Joint

Structural ASTM E330: Pass at 60 PSF
Air Leakage ASTM E283:  <0.04 CFM @ 6.24 PSF
Water (Dynamic) AAMA 501.1: Pass at 15 PSF
Water (Static) ASTM E331: Pass at 15 PSF
Interstory Drift AAMA 501.4: No damage at 1% of story height, No damage at +/-¾” vertical displacement

70 Durometer Silicone

This is commercial grade profile extrusion compound. 
Also available in color.

General Purpose: ASTM C1115, Type C

Properties Specifications Typical Value Test Method
Hardness, Type A, Pts. 70 ± 5 74 ASTM D2240
Tensile, min, MPA (psi) 5.0 (725) 8.4 (1224) ASTM D412
Elongation, Min, % 125 306% ASTM D412
Specific Gravity Report 1.37 ASTM D792
Tear Resistance, Die B,
Min, kN/m (lbf/n) 9 (51) 24.5 (140) ASTM D624
Compression Set, 22 hrs @100° C
Method B, Max, % 15 7.5% ASTM D395
Heat Resistance, 70 hrs @150° C ASTM D573
Change in Hardness, max, pts ±5 +2  
Change in Tensile, max, % ±15 +1.0  
Change in Elong., max, % ±30 -26.0  
Low Temperature Brittleness, 3 minutes @ -40° C ASTM D2137
Method A, No Cracks or Cracking   Passed  
Ozone Resistance, 100 hrs @ 300mPa @ 70° C, 20% elongation ASTM D1149
Method B, Procedure B1, 7x, No Cracks or Cracking   Passed  
Staining of Surface, 48 hrs @70° C,
Delstar Acrylic White Enamel in conjunction with Satin Primer DPE-1338
Method A, No Contact Stain   Passed  
Staining of Surface, 48 hrs w/UVA-340 bulbs per ASTM G-154,
Delstar Acrylic White Enamel in conjunction with Satin Primer DPE-1338
Method B, No Contact Stain      
Dow Corning 795 Silicone Building Sealant
Test Property Unit Result
As Supplied
ASTM C 679 Tack-Free Time, 50% RH Hours 3
  Curing Time at 25°C (70°F) and 50% RH Days 7-14
ASTM C 639 Flow, Sag or Slump Inches (mm) 0.1 (2.54)
  Working Time Minutes 20-30
  VOC Content1 g/L 28
As Cured-After 21 days at 25° (77°F) and 50% RH
ASTM D2240 Durometer Hardness, Shore A Points 35
ASTM C794 Peel Strength Lb/in (kg/cm) 32 (5.7)
ASTM C 1135 Tension Adhesion Strength    
  At 25% extension Psi (MPa) 45 (0.310)
  At 50% extension Psi (MPa) 60 (0.414)
ASTM C 719 Joint Movement Capability Percent ±50
ASTM C 1248 Staining (granite, marble, limestone, brick and concrete)   None
As Cured-After 21 days at 25° (77°F) and 50% RH followed by 10,000 hours in a QUV weatherometer, ASTM G 53
ASTM C 1135 Tension Adhesion Strength    
  At 25% extension Psi (MPa) 35 (0.241)
  At 50% extension Psi (MPa) 50 (0.345)
1 Based on South Coast Air Quality Management District of California. Maximum VOC is listed both inclusive and exclusive of ware and exempt compounds. For a VOC data sheet for a specific sealant color, please send your request to

Benefits of the ISeal Exterior Panel System

Proven Materials

The ISEAL EP system uses proven silicone materials. Silicone has been used for over 40 years in conjunction with panel products.

Installation Quality Control

The ISEAL EP extrusion is designed with sealant depth gauging tabs, which allow for easy visual confirmation of correct sealant depth and accurate alignment of panels.

Proven Performance

The ISEAL EP system, including the exoskeletal 4-way splice has been subjected to rigorous laboratory testing to validate system performance.

Faster Dry-In

With the ISEAL EP system the 4-Way splice joints are installed as the panels are erected, providing completed panel perimeter joints with each installed panel. With traditional sealant/backer rod joints the joints are typically installed after all panels are installed, leaving the building exposed to the elements during construction.

Movement Capacity

The ISEAL EP gasket is highly flexible and able to easily accommodate building movements while imparting lower loads on the panel joints as compared to a traditional sealant/backer rod joint.  This reduces the risk of adhesive joint failure.

Factory Installation Quality

Over 90% of the ISEAL EP system is shop installed in a controlled environment with rigorous quality control, eliminating the quality challenges of field installed sealant/backer rod joints.

Example Installation Details

Horizontal Seals Installed in In Plant

Horizontal Seals Installed in On-Site

Exoskeletal Seal Splice - Outside Face

Exoskeletal Seal Splice - Inside Face


Over 90% of the ISEAL EP system is shop installed. The horizontal and vertical seals are shop installed. The 4-way joint is installed in the field as the panels are set. All joints are installed by trained technicians.

The horizontal joint at the panel below and the vertical joint at the panel edge are filled with sealant to the top of the depth gauge. Finally, the Exoskeletal Seal splice is installed at the 4-way splice.

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