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Obviously, water resistance is the main attribute. However, flashing should also be: Durable and resistant to damage du

Flashing Facts Flashings must possess certain physical properties. Obviously, water resistance is the main attribute. However, flashing should also be: Durable and resistant to damage during installation. Resistant to puncturing or tearing. Easily formed into desired shapes.

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Obviously, water resistance is the main attribute. However, flashing should also be: Durable and resistant to damage du

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  1. Flashing Facts Flashings must possess certain physical properties. • Obviously, water resistance is the main attribute. However, flashing should also be: • Durable and resistant to damage during installation. • Resistant to puncturing or tearing. • Easily formed into desired shapes. • Other Considerations: • Resistance to ultraviolet light must be evaluated during flashing selection. • Flashing material should not be susceptible to corrosion in fresh mortar or react with other adjacent materials such as rigid insulation. • Compatibility with materials such as sealants or adhesives must be reviewed. • The minimum expected life of the the flashing materials should be the anticipated life of the structure

  2. Flashing “Install-ability”

  3. Flashing Comparisons SHEET METALS ADVANTAGES DISADVANTAGES Stainless Steel Durable, Impervious, Hard Difficult to bend High installation costs Must be preformed at factory Not easily field-adapted Usually requires steel workers for installation Cold-rolled Copper, Durable, flexible, impervious, Cold-rolled stains surfaces Lead-coated Copper easier to form and solder than where water runs off; damaged stainless; Lead-coated does by excessive flexing; Copper not stain corrodes and leads to gradual change in surface color COST: $ 10.00 -$ 12.00 PER SQ. FT COST: $ 10.00 - $ 12.00 PER SQ. FT

  4. Flashing Comparisons COMPOSITES ADVANTAGES DISADVANTAGES Copper Laminations Easier to form and join More easily torn than metal, than metals. asphalt degrades in sunlight and can ooze under extreme heat COST: $ 7.00 -$ 8.00 PER SQ. FT

  5. Flashing Comparisons TYPE ADVANTAGES DISADVANTAGES EPDM Not susceptible to UV rays, Requires adhesives to bond to substrate Corrosion resistant, Good and requires double sided tape to seal laps, Tear and puncture resistanceMore difficult to work with than rubberized asphalt, resulting in higher labor costs Rubberized Flexible at low temperatures Affected by UV rays Asphalt Flashing Excellent tear/puncture Cannot form 45 degree drip edge System resistance; self seals around Loses adhesive properties below 40 degrees stainless steel drip edge; Rubberized-asphalt component can ooze easy to install out to the exterior of the building in warm temperatures. TYPE ADVANTAGES DISADVANTAGES Elvaloy® Membrane Flexible at low temperatures. N/A Not susceptible to UV. Self-adhesive, easy to install, seamless preformed corners and end dams available. Extremely tough: excellent impact and tear/puncture resistance. Highly resistant to oils and will repel most chemicals Compatible with most silicone and urethane sealants. Suitable for thru-wall or surface- mount construction. *Elvaloy® is a registered trademark of the DuPont Company COST: $ 4.00 - $ 5.00 PER SQ. FT COST: $ 4.00 - $ 5.00 PER SQ. FT (including drip edge) COST: $ 5.00 - $ 6.00 PER SQ. FT (with drip edge) $ 4.00 - $ 5.00 PER SQ. FT (without drip edge)

  6. Flashing “DROOL”

  7. Stainless Steel and Copper Flashing Accessories END DAM INSIDE CORNER OUTSIDE CORNER

  8. Flashing Locations UNDER COPINGS AT WALL BASE AT ROOF/WALL INTERSECTIONS OVER OPENINGS AT SHELF ANGLES AT SILLS

  9. Termination Bar • Recommended to ensure that the top edge of the flashing will remain attached to the back-up Sealant Term Bar Foam Seal Flashing • Used at the top of flashing to mechanically secure to back-up wall. • Type 304 Stainless Steel • 9/32” holes spaced 8” o.c. • Size 1/8” x 1” x 96”

  10. Drip Plates • Drip Plates are recommended by the BIA for flashings that cannot be exposed to UV • Meets BIA requirements of extending ¼” beyond face of wall forming a drip. • Available in stainless steel and copper. • *Compatible with Clear Adhesive Flashings ONLY Flash-Adhere Strip (w/release paper) for precise and permanent placement of flashing Compressible filler adhered to the bottom of drip plate acts as a bond break and helps prevent air and moisture infiltration.

  11. Mortar Collection Device Must suspend mortar at two distinct heights

  12. Weeps and Vents • Plastic Tubes – 16” OC • Cotton Cords/Wicks – 16” OC • Honeycomb Plastic – 24” OC • Aluminum Vent – 24” OC • Synthetic Mesh – 24” OC • Open Head Joint – 24” OC • Vents at the top of the cavity can dramatically increase air ventilation to improve drainage. • *Compatible with Clear Adhesive Flashings ONLY Weep vents allow for proper drainage and ventilation helping to keep wall cavities dry and clear of debris

  13. DEFINING AIR BARRIERS vs. VAPOR BARRIERS There are two ways for moisture to infiltrate the building envelope. • Diffuse flow is a gaseous vapor that passes through all materials. • Channel flow is a more serious concern, resulting from breaches in the building envelope. Channel Flow Diffuse Flow

  14. DEFINING AIR BARRIERS vs. VAPOR BARRIERS • An air barrier MUST resist air leakage or channel flow at all pressure levels through the wall assembly. • A vapor barrier MUST resist the movement of vapor through diffusion. • NOT ALL AIR BARRIERS ARE VAPOR BARRIERS Channel Flow Diffuse Flow

  15. DEFINING AIR BARRIERS vs. VAPOR BARRIERS Air barriers or permeable membranes allow the wall to “breathe” and offer designers more flexibility in their placement within the wall assembly. The ability to make the barrier system totally continuous should be the main criteria for the location. Channel Flow Diffuse Flow

  16. DEFINING AIR BARRIERS vs. VAPOR BARRIERS Vapor barriers or non-permeable membranes have a specific location within the wall. Vapor barriers MUST be completely continuous to properly perform their function. Channel Flow Diffuse Flow

  17. DETAILINGAIR/VAPOR BARRIER INTEGRATION Intersections of different materials, expansion joints, elevation changes, inside & outside corners, and door & window openings are some areas/situations that require detailing in an air/vapor barrier system.

  18. INSTALLATIONKEYS TO A SUCCESSFUL AIR/VAPOR BARRIER The detail between an air/vapor barrier and the roofing system is critical. CONTINUITY WITH THE ROOFING SYSTEM

  19. ANCHORING SYSTEM COMPATIBILITYKEYS TO A SUCCESSFUL AIR/VAPOR BARRIER Does the anchoring system protect the integrity of the air/vapor barrier and does the air/vapor barrier seal around the anchoring system?

  20. COMPARISONLIQUID VS. SHEET MATERIALS

  21. CONTRACTORSINSTALLATION AND EDUCATION Be sure to use a company with personnel trained/certified for installing air barrier systems. A pre-installation jobsite meeting is recommended to go over specific project requirements.

  22. COMPATIBILITY

  23. Building Envelope Summary • Flashings must work as a system and include all components such as termination bar, drip plates, mortar collection device, weeps/vents, etc. • User-friendly flashing systems for field personnel are important • Air/Vapor barriers MUST be totally continuous and be able to tie into adjacent building components via proper detailing. • Breathable vs. Non-breathable?

  24. HOHMANN AND BARNARD, INC. 30 RASONS CT. HAUPPAUGE, NY 11788 p: 800-645-0616 f: 631-234-0683 e: weanchor@h-b.com www.h-b.com CHRIS BUPP p: 717-779-4943 chrisb@h-b.com

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