Flashing Facts Flashings must possess certain physical properties

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 flashing materials should be the anticipated life of the structure

Flashing “Install-ability”

Flashing Comparisons SHEET METALS ADVANTAGES DISADVANTAGES Stainless Steel Durable, Impervious, Hard High installation costs Difficult to bend COST: $ 10. 00 -$ 12. 00 PER SQ. FT Cold-rolled Copper, Durable, flexible, impervious, Lead-coated Copper easier to form and solder than stainless; Lead-coated does not stain COST: $ 10. 00 - $ 12. 00 PER SQ. FT Must be preformed at factory Not easily field-adapted Usually requires steel workers for installation Cold-rolled stains surfaces where water runs off; damaged by excessive flexing; Copper corrodes and leads to gradual change in surface color

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

Flashing Comparisons TYPE ADVANTAGES DISADVANTAGES EPDM susceptible to UV rays, Requires adhesives to bond to substrate Elvaloy® Membrane Not Flexible at low temperatures. N/A Corrosion resistant, Good and requires double sided tape to seal laps, Not susceptible to UV. Tear and puncture resistance More difficult to work with than rubberized Self-adhesive, easy to install, asphalt, resulting in higher labor costs COST: $ 4. 00 - $ 5. 00 PER SQ. FT seamless preformed corners and end dams available. Rubberized Flexible at tough: low temperatures Affected by UV rays Extremely excellent Asphalt Flashing Excellent tear/puncture impact and tear/puncture resistance. Cannot form 45 degree drip edge System resistance; self seals around Loses adhesive properties below 40 degrees Highly resistant to oils and will stainless steel drip edge; Rubberized-asphalt component can ooze repel most chemicals easy to install out to the exterior of the building in warm Compatible with most silicone and temperatures. COST: $ 4. 00 - $ 5. 00 PER SQ. FT (including drip edge) urethane sealants. Suitable for thru-wall or surfacemount construction. COST: $ 5. 00 - $ 6. 00 PER SQ. FT (with drip edge) $ 4. 00 - $ 5. 00 PER SQ. FT (without drip edge) *Elvaloy® is a registered trademark of the Du. Pont Company

Flashing “DROOL”

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

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

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”

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

Mortar Collection Device Must suspend mortar at two distinct heights

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. Weep vents allow for proper drainage and ventilation helping to keep wall cavities dry and clear of debris

DEFINING AIR BARRIERS vs. VAPOR BARRIERS There are two ways for moisture to infiltrate the building envelope. 1. Diffuse flow is a gaseous vapor that passes through all materials. 2. Channel flow is a more serious concern, resulting from breaches in the building envelope. Channel Flow Diffuse Flow

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

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

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

DETAILING AIR/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.

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

ANCHORING SYSTEM COMPATIBILITY KEYS 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?

COMPARISON LIQUID VS. SHEET MATERIALS Wall System Liquid Sheet Steel/Sheathing ✔ ✔ ✔ ✖ Concrete/ICF CMU

CONTRACTORS INSTALLATION 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.

COMPATIBILITY

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?

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