/
WALL PERFORMANCE BY DESIGN: The Role of Rainscreens in Mois WALL PERFORMANCE BY DESIGN: The Role of Rainscreens in Mois

WALL PERFORMANCE BY DESIGN: The Role of Rainscreens in Mois - PowerPoint Presentation

alexa-scheidler
alexa-scheidler . @alexa-scheidler
Follow
398 views
Uploaded On 2017-07-04

WALL PERFORMANCE BY DESIGN: The Role of Rainscreens in Mois - PPT Presentation

Laverne Dalgleish Building Enclosure Moisture Management Institute BEMMI Todays Agenda BEMMI Background Exterior Wall Science As I Live and Breathe Traditional Rainscreen Design Engineered ID: 566561

exterior wall code rainscreen wall exterior rainscreen code design requirements water engineered envelope www building r703 moisture materials cladding

Share:

Link:

Embed:

Download Presentation from below link

Download Presentation The PPT/PDF document "WALL PERFORMANCE BY DESIGN: The Role of ..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.


Presentation Transcript

Slide1

WALL PERFORMANCE BY DESIGN: The Role of Rainscreens in Moisture Management

Laverne Dalgleish

Building

Enclosure Moisture Management Institute (BEMMI)Slide2

Today’s Agenda

BEMMI Background

Exterior Wall Science: As I Live and Breathe!

Traditional

Rainscreen

Design

Engineered

Rainscreen

Design

Absorptive Cladding

Building Code Requirements and Compliance

BibliographySlide3

Building Enclosure Moisture Management Institute

Founded in 2009

Founding Members:

Advanced Building Products

Benjamin

Obdyke

Cosella-Dörken

CavClear/

ArchovationsSlide4

BEMMI Mission

To promote the growth of the engineered

rainscreen

products industry to improve moisture management in building enclosures through technical advocacySlide5

Exterior Wall Science: As I Live and Breathe!

Exterior Wall Assembly

Wall Covering Assembly

Water-Resistive Barrier

Insulating Sheathing (continuous insulation)

Structural Framing, Sheathing, Cavity Insulation

Interior Finish Materials

Air Barrier Requirements

PenetrationsSlide6
Slide7
Slide8

Traditional Rainscreen Design

Ventilated Cladding

Anchored Brick and Stone Veneers

Wood Shakes and Shingles

Clapboards

Drainage

and

DryingSlide9

Traditional Rainscreen DesignSlide10

Absorptive Cladding

Masonry and Stucco

Adhered Veneers

Wood Siding Materials

Engineered-wood Siding Materials

Cement-based Siding MaterialsSlide11

Absorptive CladdingsSlide12

Engineered Rainscreen Design

Bulk Water Drainage

Ventilation –

Precipitation, Condensation

E

vaporation, Respiration

Capillary Break Space – Isolate CladdingSlide13

Engineered Rainscreen Design

Types of Rainscreen Materials

3-dimensional membrane

3-dimensional

m

esh

s

tyle

Polymer-based productsRoll out similar to water-resistive barriersContinuous airspaceSlide14

Engineered

Rainscreen

DesignSlide15

0.25 in (6mm)

0.40 in (10mm)

Meets Canadian Building Code

Engineered

Rainscreen

DesignSlide16

Engineered Rainscreen DesignSlide17

Engineered Rainscreen DesignSlide18

Code Requirements: 2012 IRC

SECTION R703

EXTERIOR COVERING

R703.1 General.

Exterior walls shall provide the

building with

a weather-resistant exterior wall envelope. The

exterior wall

envelope shall include flashing as described in Section R703.8.R703.1.1 Water resistance. The exterior wall envelope shall be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a water-resistant barrier behind the

exterior veneer as required by Section R703.2 and a means of draining to the exterior water that enters the assembly. Protection against condensation in the exterior wall assembly shall be provided in accordance with Section R702.7 of this code.Slide19

Code Requirements: 2012 IRC

Exceptions:

1. A weather-resistant exterior wall envelope

shall not

be required over concrete or

masonry walls designed

in accordance with Chapter 6

and flashed

according to Section R703.7 or R703.8.Slide20

Code Requirements: 2012 IRC

Exceptions (cont.):

2

. Compliance with the requirements for a

means

of drainage

, and the requirements of

Sections R703.2

and R703.8, shall not be required for an exterior wall envelope that has been demonstrated to resist wind-driven rain through testing of the exterior wall envelope, including joints, penetrations and intersections with dissimilar materials,

in accordance with ASTM E 331 under the following conditions:Slide21

Code Requirements: 2012 IRC

2.1. Exterior wall envelope test

assemblies shall

include at least one opening,

one control

joint, one wall/eave interface

and one

wall sill. All tested openings

and penetrations shall be representative of the intended end-use configuration.2.2. Exterior wall envelope test assemblies shall be at least 4 feet by 8 feet (1219 mm by 2438 mm) in size.Slide22

Code Requirements: 2012 IRC

2.3 Exterior

wall assemblies shall be

tested at

a minimum differential pressure

of 6.24

pounds per square foot (299 Pa).

2.4. Exterior wall envelope assemblies

shall be subjected to the minimum test exposure for a minimum of 2 hours.Slide23

Code Requirements: 2012 IRCPass / Fail Criteria

Exception 2

(cont.):

The

exterior wall envelope

design shall

be considered

to resist wind-driven rain

where the results of testing indicate that water did not penetrate control joints in the exterior wall envelope, joints at the perimeter of openings penetration

or intersections of terminations with dissimilar materials.Slide24

ASTM E331

Water penetration test.

Simulates 8” rain / hr. with 50 mph wind. Slide25

Code Requirements: 2012 IRC

IRC Provides Basic

P

erformance Measures

Minimum Code (minimum legal requirements)

Beyond Code:

Durability

Drainage and Drying

Moisture Management as Preventative Measure Slide26

Performance Expectations

Help Remove Bulk Water

Promote Drying of Incidental and Absorbed Water

Improve Condensation ManagementSlide27

ICC-ES (Evaluation Services)

Meeting the

I

ntent of the

C

ode

ICC-ES Acceptance Criteria: AC356

Drainage TestAccelerated Aging & Weathering

Durability / Fungi ResistanceUV ExposureFire Resistance (optional)Slide28

Blower-Door TestingSlide29

Problem Areas

Tighter the wall, the less it dries

Penetrations and openings create moisture movement issues

Less expensive to address upfront than to fix laterSlide30

Engineered Rainscreen Performance

Drain bulk water from behind the cladding

Provide ventilation drying for other incidental moisture

Separates cladding from WRB

Capillary break

Surfactant issues, enhance WRB durability

C

ontinuously over entire wall surfaceSlide31

Engineered Rainscreen Details

Rainscreen MaterialSlide32

Review

BEMMI Background

Exterior Wall Science: As I Live and Breathe!

Traditional

Rainscreen

Design

Engineered

Rainscreen

DesignAbsorptive CladdingBuilding Code Requirements and ComplianceBibliographySlide33

Questions?Slide34

Bibliography

Advanced

Building Products

www.mortairvent.com

Air Barrier Association of America

www.airbarrier.org

CavClear/

Archovations www.cavclear.com Building Enclosure Moisture Management Institute www.bemmi.org

Benjamin Obdyke www.benjaminobdyke.comCosella-Dörken www.cosella-dorken.comInternational Code Council, Evaluation Services

www.icc-es.orgInternational Code Council www.iccsafe.orgMasonry Veneer Manufacturers Association www.masonryveneer.org NAHB Research Center White Paper

www.toolbase.org/PDF/DesignGuides/RainScreenDesigns.pdf