Transcript VPS Presents - PaintSquare

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
Flashing “Install-ability”
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
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
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 DuPont 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
Steel/Sheathing
Concrete/ICF
CMU
Liquid
Sheet
✔
✔
✔
✔
✔
✖
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: [email protected]
www.h-b.com
CHRIS BUPP
p: 717-779-4943
[email protected]