Transcript Rainscreen & Ventilated Facade System

Drained/Back-Ventilated Rain Screen System
Copyright 2010-2011, Facade Works Inc www.facadeworksinc.com
OBJECTIVES
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What is Drained/Back Ventilated rainscreen?
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Components of Exterior HPL panels.
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Rainscreen details and installation methods.
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Drained/Back-Ventilated Rain Screen
The Rain Screen Principle
•
Water/Moisture Control
•
Ventilation
•
Breathability
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RAIN SCREEN
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.
When it rains…
Panels deflect most of the
rain water
Only 15% of the rain enters
the cavity & exits at the
perforated vent at grade
Less than .5% reaches the
weather barrier
Moving air through the
cavity helps remove
condensation
Gap Size between Panels is
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Inc or 8mm
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D/B-V Rainscreen
Based on 2 separate leafs
(Outer and Inner)
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Outer = First line of
defense, Water Control
Inner = Secondary line
of defense – moisture
barrier, Vapor/Air
Barrier, insulation,
structural
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Ventilation & “Breathe-ability”
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Open joints and openings at
top & bottom of façade.
Constant air flow dries up
any moisture/rainfall left
inside the cavity
Ventilation cavity allows hot
air to flow upward and out of
cavity without penetrating or
migrating through wall.
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When the sun shines.. or when it’s cold
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Solar Protection - Air
moving through the
cavity prevents heat
accumulation cooling
the inner layers of the
wall assembly
Reduces the demand
for cooling energy.
When cold - Air flow in
cavity is heated by
building thus causing
any condensation or
any penetrating rain
to dry.
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D/B-V Rain Screen System Details
Components of VRS
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Panel
Vertical Support
Members
“Compartment-ized”
air cavity
Breathable Weather
Barrier
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Improper Installation
Insufficient Ventilation =
Oxidation
Insufficient Ventilation =
Corrosion, dry rot,
mold, mildew
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HPL Rainscreen Installation
Methods
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Exposed Fastener Systems
Concealed Fastener Systems
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Facades
Construction Details
Horizontal Sections
Alu-Substructure Riveted
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Ventilation Cavity
Minimum of 1”
between laminate panel
and substrate
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Base
• Required clearance
of 2-4” above
ground level to
insure adequate air
intake.
• Base capped with a
ventilation profile
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Parapet
•Top must have a
minimum of ¼”
clearance between the
parapet and panel for
proper ventilation
•Air flow is from
bottom to top
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Vertical Panel Joint
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Visible Mechanical Fastenings
Exposed Fastening
Rivets or Screws
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Fastening With Rivets
•Color coated
rivets on an
aluminum extruded
carrier rail.
•Finished product
with open
expansion joints
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HPL Panels with screws on Wood
Substructure
Weather Barrier
Framing
Rear Ventilation Rain Screen
•Weather / Air Barrier
•Substructure
•Option insulation
Insulation
•Airspace Between #1 or 3 or 1
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HPL Panels with rivets on Aluminum
Substructure
Weather Barrier
Aluminum
Substructure
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Insulation
Installation
Each panel should have one fixed
point (the hole is the same size as
the shaft diameter of the fastener),
and the remaining holes are sliding
points (the hole size is 1-2mm larger
than the shaft size of the fastener).
This allows for hygric movement of
the panel.
Screws should not be over tightened
or countersunk.
HPL panel manufacturers should be
consulted when calculating edge
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and
fastener spacing.
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Concealed Fastener Systems
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Allows for clean, aesthetic
design
Clips attach to back of
panel with rivets, then
mount on rail system
More labor intensive
installation
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Concealed Fastener System Details
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