PAREX® WeatherBlock VB AB
Acrylic co-polymer fast drying vapor impermeable, elastomeric waterproof and air barrier coating which can be either rolled, brushed, or spray applied.
- Extremely flexible
- Bridge cracks and accomodate small movements up to 1/32 in. (0.8mm)
- Bridges 1/8 in. (3mm) gaps at sheathing board joints with SikaWall Sheathing Fabric embedded.
- Low VOC
Usage
Designed for use as vapor barrier behind exterior claddings.Advantages
- Extremely flexible
- Bridge cracks and accomodate small movements up to 1/32 in. (0.8mm)
- Bridges 1/8 in. (3mm) gaps at sheathing board joints with SikaWall Sheathing Fabric embedded.
- Low VOC
Packaging
60 lb (27.2 kg) net weight in plastic pails
Product Details
Shelf Life
12 months when protected from rain and moisture
Storage Conditions
Protect from sun and freezing at all times
Volatile organic compound (VOC) content
| EPA Reference Test Method 24 | US EPA, South Coast AQMD and | 10 g/L (Meets SCAQMD Rule 1113) |
Tensile Strength
| TEST | METHOD | ICC and ASTM E2570 Criteria | RESULTS |
| Tensile Bond | ASTM D4541 | >15 psi | 28 psi |
| Tensile Bond Strength | ASTM E 2134/ | Minimum 15 psi (104 kPa) | Pass all listed substrates and flashing materials |
Elongation
| Elongation | ASTM D412 | No Criteria |
|
Resistance to Weathering
| Accelerated Weathering | AC 212 | 25 Cycles followed by Hydrostatic Pressure Test: No water penetration on the plane of the exterior facing side of the substrate. | Pass: No water penetration |
| Freeze-Thaw Resistance | ASTM E 2485 | 10 Cycles | Pass: No Deleterious Effects |
| Hydrostatic Pressure Test | AATCC 127 (Water Column) | Resist 21.6 in (55 cm) water for 5 hours before and after aging | Pass: No water penetration |
| Water Resistance | ASTM D 2247 | 14 Days | Pass: No Deleterious Effects. |
| Water Penetration | ASTM E331 | 2.86 psf (137 Pa) for 15 minutes | Pass: 25.4 psf (1216 Pa) for 165 minutes |
| Water Penetration | ASTM E331 | Tested after Structural Loading, Racking and Restrained Environmental Cycling at 2.86 psf (137 Pa) for 15 minutes | Pass: No Water Penetration |
| Water Vapor Transmission | ASTM E96 Procedure B | Class 1 | 0.09 perms |
| Weathering | ICC ES AC 212/ASTM E2570 | 210 hours of UV Exposure, 25 cycles of accelerated weathering, 21.6 in (549mm) water column for 5 hours | Pass |
| Wind Driven Rain | F.S. TT-C-555B | No Criteria | Pass |
Durability
| Nail Seal Ability, Head of Water | ASTM D1970 | No Criteria | Pass: 5 inches of water |
| Racking | ASTM E72 | Deflection at ⅛ in (3.2mm) | Pass: No cracking at field, joints or flashing connection |
| Restrained Environmental | ICC ES AC 212 | 5 Cycles of wetting and drying | Pass: No cracking at field, joints or flashing connection |
| Structural Loading | ASTM E1233 Procedure A | 10 Cycles @ 80% design load | Pass: No cracking at field, joints or flashing connection |
Air permeance
| Air Infiltration | ASTM E2178 | Calculated flow Rate at 75 Pa (1.57 lb/ft2, 0.3 in H2O) = < 0.02 L/m2*s (< 0.004 cfm/ft2) | <.00001 L/m2*s (0.00001 cfm/ft2) at 75 Pa (1.57 lb/ft2, 0.3 in H2O) |
| Air Leakage of Air Barrier Assemblies | ASTM E2357 | ASTM E2357 | Pass: <0.2 L/s·m2 at 75 Pa) (<0.04 cfm / ft2 at 1.57 psf) |
| Air Leakage | ASTM E283 | No Criteria | <0.004 cfm/ft2 |
Application
Substrates
Acceptable substrates:
Glass mat gypsum sheathing
Exterior-grade gypsum sheathing
Exposure 1 exterior plywood
Exposure 1 OSB
Concrete
Concrete masonry
Brick
Cement board sheathing.
Drying Time
Typically 45 min - 2 hours depending upon temperature, humidity and substrate.
Coverage
- 100-125 ft2. (9-12 m2) per pail (when 2 coats needed)
- 200-250 ft2. (18-23 m2) per pail (when 1 coat needed)
SUBSTRATE PREPARATION
- Remove surface contaminants such as dust or dirt without damaging the substrate.
- Painted substrates must have the paint removed by methods which result in no more than 10% of the remaining surface having paint.
- For additional options for surface preparation, contact Sika Facades Technical Support.
MIXING
- Use clean equipment for mixing and preparation.
- Stir PAREX® WeatherBlock VB AB to a uniform consistency. Avoid creating air bubbles or foam.
- For some spray applications it may be necessary to thin PAREX® WeatherBlock VB AB slightly. Use only clean potable water and add sparingly, never more than 16 oz (0.5L) per pail, because thinning can reduce film thickness.
- Non Sika Facades approved additives of any kind, such as rapid binders, anti-freeze, accelerators, fillers, pigments, etc. should not be added under any circumstances.
APPLICATION
- Read entire label before using this product.
- PAREX® WeatherBlock VB AB is easily applied with roller, brush or suitable spray equipment. Sprayed applications require backrolling. Contact Sika Facades Technical Support for recommended spray equipment.
- Use 1 1/4 in. (32mm) or 1 3/8 in. (35mm) nap roller designed for applying latex paints.
- Apply PAREX® WeatherBlock VB AB approximately 6 in. (150mm) wide centered over:
- Sheathing joints
- Sheating board gaps up to 1/4 in. (6mm) wide
- Open holes up to 1 in. (25mm) across
- Back flanges of flashings and drip track
- Immediately place the SikaWall Sheathing Fabric centered in the wet PAREX® WeatherBlock VB AB. Run a trowel or taping knife over the sheathing fabric to embed it into the wet PAREX® WeatherBlock VB AB. Do not let PAREX® WeatherBlock VB AB skin over before applying and embedding SikaWall Sheathing Fabric. Work in small enough areas to ensure that PAREX® WeatherBlock VB AB is wet when SikaWall Sheathing Fabric is embedded in it. If PAREX® WeatherBlock VB AB does skin over before embedding SikaWall Sheathing Fabric, scrape off semi-liquid PAREX® WeatherBlock VB AB or let it dry and re-apply.
- Apply additional PAREX® WeatherBlock VB AB to entirely cover the SikaWall Sheathing Fabric. Correct larger gaps and holes by replacing sheathing.
- As an alternative method for joint treatment use SikaWall MaxFlash. Work SikaWall MaxFlash flush with the surface. Overlap both sides of the gap onto sheathing min 1”. See SikaWall Maxflash data sheet for details and installation instructions.
- Apply PAREX® WeatherBlock VB AB over the entire outer sheathing surface, at a rate of not more than 50 ft2 per gal. (1.2 m2/l), once SikaWall Sheathing Fabric is firmly embedded. Apply 60 wet mils (approx 40 dry mils) in minimum of two coats. Multiple coats should be allowed to dry between coats. Check the wet film thickness with mil thickness gauge to insure proper coverage. The transparency of the PAREX® WeatherBlock VB AB is not an indication of the thickness.
- For spray applications, strain the material using a paint strainer before sparying material.
CLEANING
Water soluble prior to drying. Clean tools and containers with water prior to drying.