Design, Assessment, & Repair of Exterior Wall Systems

CCFM CONFERENCE 2011 | SAINT LOUIS

Kevin A. Kalata, RA, SE WJE Wiss, Janney, Elstner Associates, Inc.

“Conference for Catholic Facility Management” is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited.

Learning Objectives

At the end of this program, participants will be able to:

1. Identify the components of barrier, cavity drainage, and rain screen exterior wall systems and will learn the pros and cons of these wall systems. 2. Identify basic detailing and construction problems related to exterior wall systems. 3. Assess options for field testing of problematic exterior wall conditions. 4. Evaluate general repair options and techniques for exterior wall systems including brick masonry, stone, stucco/EIFS, and windows. Outline

1. Importance of Well-Designed Exterior Walls 2. Types of Wall Systems 3. Assessing / Identifying Problem Details and Conditions 4. Maintenance & Repair 5. Building Envelope Resources Exterior Wall Problems Importance of Well Designed Exterior Walls

. Water Penetration . Condensation . Air Infiltration / Exfiltration . Thermal Bridging . Structural Deterioration . Corrosion . Decay . Mold/Mildew Growth Exterior Wall Problems Water Penetration Exterior Wall Problems Condensation

Thermal Bridging

Air Infiltration/Exfiltration Exterior Wall Problems Structural Deterioration

Corrosion Exterior Wall Problems Structural Deterioration

Decay Exterior Wall Problems Mold/Mildew Exterior Wall Problems Mold/Mildew Exterior Wall Problems Mold/Mildew…and Mushrooms Leaks and Lawsuits Uncontrolled water leakage and moisture penetration are two of the most common threats to the performance of the building envelope and make up approximately 70% of all construction related claims.

Roofing 23%

Waterproofing 5% Façade 41% Structural 19%

Interior Delay Slip/Fall 2% 5% 5% Maintenance and Repair Costs

BOMA’s 2009 Experience Exchange Report (EER)

. Private sector office buildings spend $1.80 per sq. ft. (22.6% of building’s operating expenses)

. Government buildings spend $2.43 per sq. ft.

. Religious assembly buildings spend ……

Types of Wall Systems Design Approaches Three Main Design Approaches 1. Barrier System 2. Drainage System 3. Rain Screen System Alternate Classification 1. Barrier System 2. Mass Wall System 3. Drainage (Cavity) System Types of Wall Systems Barrier System

. Relies on one line of defense against leakage. . Water that penetrates barrier can result in leakage. . Joints and interface details must be watertight. . Typically relies on sealants, therefore, installation and maintenance is critical. . Typically more cost effective (initially) than alternative wall systems.

Types of Wall Systems Barrier System

Examples of Barrier Wall Systems: . Precast Concrete Panels . Single Wythe Concrete Masonry Unit (CMU) . Barrier Metal Panels . Barrier Exterior Insulation and Finish System (EIFS)

Types of Wall Systems Barrier System Mass Wall – a variation of a barrier system that relies on wall thickness and storage capacity of wall materials to resist water penetration

Examples . Masonry Mass Wall . Masonry Composite Wall

Types of Wall Systems Barrier System

Barrier Wall Mass Wall

Images courtesy Whole Building Design Guide Types of Wall Systems Barrier System – Metal Panels Types of Wall Systems Barrier System - EIFS Types of Wall Systems Barrier System – Concrete Masonry Types of Wall Systems Barrier System – Barrier Mass Wall

Stone / brick mass wall Types of Wall Systems Drainage (Cavity) Wall System

. Relies on multiple lines of defense against water penetration (redundant system) . Assumes water will penetrate cladding . System in place to collect and drain water penetration (moisture barrier & flashings) . Higher initial costs but better chance of long term success over barrier systems Types of Wall Systems Drainage Wall System - Components

Exterior cladding: Initial line of defense intended to shed or absorb the majority of rainwater

Air space: Drainage cavity intended to provide avenue for water flow and drying of cladding

Moisture barrier: Drainage plane and flashings intended to serve as the primary line of defense against water penetration

Air barrier: Element intended to control movement of air across the wall system; often combined with moisture barrier

Insulation: Can be located inboard or outboard of air/moisture barrier depending on climate

Backup wall: Structure located inboard of exterior wall cladding

Vapor retarder: Element intended to control movement of water vapor across the wall system; depending on placement of insulation may be combined with air/moisture barrier Types of Wall Systems Drainage (Cavity) Wall System - Components

Drainage (Cavity) Wall

Images courtesy Whole Building Design Guide Types of Wall Systems Drainage Wall System – Masonry / Metal Panel Types of Wall Systems Drainage Wall System – Masonry Cavity Wall Types of Wall Systems Drainage Wall System – EIFS and Stucco

EIFS drainage

Stucco drainage Types of Wall Systems Drainage Wall System - Components

Thermally Broken Subsill Flashing Subsill Flashing End Dam Types of Wall Systems Rain Screen Wall System

. Types include: Simple/Open/Back Vented/Pressure Equalized . Contains many of the same elements and is similar in water management to drainage wall design. . Controls air pressure flows across the wall assembly. . Pressure Equalization minimizes the amount of water reaching the air barrier. Types of Wall Systems Rain Screen Wall System

. Pressure Equalized Components . Outer cladding . Cavity: typically compartmentalized, drained and vented to exterior . Inner wall plane with air barrier and flashings Assessing Problem Details & Conditions

. Pre-Construction . Post-Construction Assessing Problem Details & Conditions Pre-Construction Drawing Review / Peer Review . Envelope should maintain consistent approach. . Continuity is to be provided in wall components. . Moisture barrier / Air barrier / Vapor retarder / Insulation . Proper integration detailing is to be provided. . Designs should be efficient. Computer Simulations / Analysis . THERM . WUFI Mock-ups

Assessing Problem Details & Conditions System Continuity

Discontinuous moisture barrier Assessing Problem Details & Conditions System Continuity

Discontinuous Air Barrier Assessing Problem Details & Conditions System Continuity

Discontinuous Air Barrier at steel tube penetrations Assessing Problem Details & Conditions System Continuity

Discontinuous Air Barrier Assessing Problem Details & Conditions System Continuity

Discontinuous Vapor Retarder Assessing Problem Details & Conditions Integration Details

. Integration details occur where multiple building envelope systems meet. . A system must be designed and implemented to maintain the performance of the envelope at these areas. . Maintain continuity in insulation, air barrier, moisture barrier, and vapor retarder. Assessing Problem Details & Conditions Integration Details Causes of Integration Detail Problems: . Complicated exterior design concept with numerous corners and systems . Incomplete design (not shown) . Shop drawings only prepared for individual systems and not typically coordinated . Shop drawings not prepared for all systems (e.g., masonry) . Reliance on surface seals . Incompatible material interfaces Assessing Problem Details & Conditions Integration Details

Complicated interface detailing Assessing Problem Details & Conditions Integration Details

Lack of interface detailing Assessing Problem Details & Conditions Integration Details

Lack of interface detailing / shop drawing coordination between masonry drainage wall and sloped glazing Assessing Problem Details & Conditions Integration Details

Lack of interface detailing/shop drawing coordination Assessing Problem Details & Conditions Integration Details

Lack of interface detailing Assessing Problem Details & Conditions Integration Details

Another building … same issue Assessing Problem Details & Conditions Integration Details

Shop Drawing Coordination Assessing Problem Details & Conditions Integration Details

Shop Drawing Coordination Assessing Problem Details & Conditions Integration Details Integration Detail Considerations . Provide continuous secondary line of defense. . Maintain continuity of flashing systems. . Install end dams at flashing terminations. . System must be water and air tight. . Avoid thermal shorts. Avoid metal sections (or combinations) extending through the wall. . Maintain continuity of vapor retarders. Assessing Problem Details & Conditions Efficient Designs

St. Louis Climate Zone 4A ASHRAE 90.1 – 2007 Climate Zones Assessing Problem Details & Conditions Efficient Designs

Effective Insulation: Continuous versus discontinuous

ASHRAE 90.1 – 2007 Assessing Problem Details & Conditions Computer Simulations

. Pre-Construction - predict design performance . Post-Construction – investigative tool

Assessing Problem Details & Conditions Computer Simulations Programs . THERM . Developed at LBNL . Based on finite element analysis . Models two-dimensional heat transfer effects on building components (windows, wall, roofs, etc.)

. WUFI . Developed at ORNL . Predicts hygrothermal performance of walls and roofs . Calculates transient coupled one-dimensional heat and moisture transport in multi-layer building materials . Can use site specific measured weather data

Assessing Problem Details & Conditions Computer Simulations

THERM plot of curtain wall showing temperature gradients Assessing Problem Details & Conditions Computer Simulations

. Concrete column

. Stone veneer

. Air space / drainage layer

. Rigid insulation

. Copper flashing

. Air space

. Wood column

THERM model of Holy Name Cathedral repairs Assessing Problem Details & Conditions Computer Simulations

Calculation “film” Calculation results Shows direction of heat and moisture flow

WUFI Assessing Problem Details & Conditions Mock-Ups

On-site Mock-ups . Can incorporate numerous potentially problematic details. . Can review aesthetic and performance issues. . Better chance of getting actual construction crew. . Can be reviewed during preconstruction meetings and during construction. . Tests performed typically involve water and air penetration and, in some cases, condensation. Assessing Problem Details & Conditions Mock-Ups Assessing Problem Details & Conditions Mock-Ups Assessing Problem Details & Conditions Post-Construction: Visual Review / Inspection

. Visual Review / Inspection . General Maintenance Review . Binocular Survey . Up-Close Inspection . Scaffolding . Crane or boom lift . Swingstage / Repelling Assessing Problem Details & Conditions Post-Construction: Visual Review / Inspection

Scaffolding / crane or boom lift Assessing Problem Details & Conditions Post-Construction: Visual Review / Inspection

Swingstage Rappelling Assessing Problem Details & Conditions Post-Construction: Visual Review / Inspection

. Testing . Water testing . Air testing . Structural testing Assessing Problem Details & Conditions Post-Construction: Testing

Water Testing – ASTM E1105 & AAMA 501.2 Assessing Problem Details & Conditions Post-Construction: Testing

Water Testing – ASTM C1715 Assessing Problem Details & Conditions Post-Construction: Testing

Keys to successful water tests: . Review existing documents: drawings, shop drawings, maintenance records, repairs, previous investigations. . Systematically attack the problem – start low. . Use the right equipment/test for the job. . Isolate components during the test. . Do not stop testing after a source is found – others may be present. . Create interior inspection openings before the test starts to allow for visual review during the test. . Don’t put the blinders on.

Assessing Problem Details & Conditions Post-Construction: Testing

Air Testing ASTM E783 Assessing Problem Details & Conditions Post-Construction: Testing

Structural Testing Repair of Exterior Wall Systems

Representative Repairs . Masonry . Stone . EIFS/Stucco . Windows . Sealants . Flashings . Air Barrier / Insulation / Vapor Retarder Repair of Exterior Wall Systems Masonry: Tuckpointing

Deteriorated Masonry Repair of Exterior Wall Systems Masonry: Tuckpointing Tuckpointing Repairs . Remove existing mortar ¾ in. minimum by grinding or had chipping. . Use appropriate pointing mortar. . May be appropriate to perform an analysis of existing mortar. . Install mortar in multiple lifts. . Concave tooled joints provide best resistance against water penetration.

Tuckpointing repairs Repair of Exterior Wall Systems Masonry: Shelf Angle / Lintel Repairs Repair of Exterior Wall Systems Masonry: Lateral Anchorage

Inadequate engagement of existing lateral ties to masonry veneer Repair of Exterior Wall Systems Masonry: Lateral Anchorage

Helical repair anchors Repair of Exterior Wall Systems Masonry: Lateral Anchorage

Helical anchor installation Helical anchor field testing Repair of Exterior Wall Systems Masonry: Bulging

Bulged exterior stone from water rundown through coping and scupper Repair of Exterior Wall Systems Masonry: Bulging

Coping repair details at bulged wall Repair of Exterior Wall Systems Masonry: Bulging

Mass wall - localized rebuild Repair of Exterior Wall Systems Masonry: Unaccommodated Expansion

No horizontal expansion joints provided Repair of Exterior Wall Systems Masonry: Unaccommodated Expansion

Rotated parapet wall sections Repair of Exterior Wall Systems Masonry: Unaccommodated Expansion

Horizontal expansion joint repair at shelf angle Repair of Exterior Wall Systems Masonry: Unaccommodated Expansion

Unaccommodated horizontal and vertical expansion Repair of Exterior Wall Systems Masonry: Settlement and Stabilization

Exterior wall step cracking due to foundation settlement Repair of Exterior Wall Systems Masonry: Settlement and Stabilization

Resistance Pier (mini-piles) installation beneath exterior walls Repair of Exterior Wall Systems Masonry: Stone Cracking/Spalling

Spalls at corroded shelf angle Repair of Exterior Wall Systems Masonry: Stone Cracking/Spalling

Crack/Spall at stress concentration Spall at corroded kerf anchor Repair of Exterior Wall Systems Masonry: Dutchman Repairs

Dutchman repairs Repair of Exterior Wall Systems Masonry: Steel Preparation

Steel preparation and testing for chlorides Repair of Exterior Wall Systems Stucco / EIFS

Studies show that over 50 percent of EIFS problems are located at windows.

Problematic corner detailing Repair of Exterior Wall Systems Stucco / EIFS

EIFS tight to window frame Sealant not adhered to base coat Repair of Exterior Wall Systems Stucco / EIFS

Insert Harbor detail

EIFS window sill repair detail Repair of Exterior Wall Systems Stucco / EIFS

EIFS is prone to punctures Repair of Exterior Wall Systems Stucco / EIFS

Separations occur when stucco lath is not tied to accessories. Repair of Exterior Wall Systems Stucco / EIFS

Stucco lath continuous through control joint/expansion joint.

Control/expansion joint repair Repair of Exterior Wall Systems Windows

Typical window problems Repair of Exterior Wall Systems Windows

Glazing cap bead repairs Repair of Exterior Wall Systems Windows

Sometimes it’s just time to replace. Repair of Exterior Wall Systems Sealants

. First line of defense against air and water leakage. . Avoid having this as the only system that integrates different wall systems. . Assume that water will penetrate seals through porous substrates. . Maintain good sealant profiles and proper installation procedures. . Verify compatibility with substrate & adjoining sealants . Keep manufacturer involved in QC program. Repair of Exterior Wall Systems Sealants

Common Causes for Failures . Inadequate bond surface preparation . Inappropriate sealant selection . Poor sealant profile . 3-sided adhesion . Poor environmental conditions during installation . Excessive movement . Age Repair of Exterior Wall Systems Sealants

Three-sided adhesion failure

Adhesive failure Cohesive and adhesive failure Repair of Exterior Wall Systems Sealants

Sealant repair details Repair of Exterior Wall Systems Sealants

Alternate Sealant Repair Options . Lead cames at coping and watertable joints . Preformed silicone seals at flush joints Repair of Exterior Wall Systems Sealants

Two-stage sealant joint Repair of Exterior Wall Systems Flashings Metal Flashings . Use a system that will allow field adjustments. . Joints and corners are critical. Soldered sections are preferable (in lieu of cuts and folds). . Corrosion protection is critical (in wet zone). . Common Materials: . Stainless steel . Prefinished aluminum . Copper / Lead coated copper Repair of Exterior Wall Systems Flashings Membrane Flashings . Will allow for tolerances . Must be flexible . Must bond long-term (surface preparation is critical) . May be exposed to UV for extended periods during construction/repairs . Examples: . Rubberized asphalt (peel and stick) . Butyl sheet . EPDM . Extruded silicone Repair of Exterior Wall Systems Flashings

Installation/Design Issues . Lack of end dam . Penetrations . Backpitched Repair of Exterior Wall Systems Flashings

Installation/Design Issues . No repair is foolproof . Provide peer review and quality control programs

…Peel ‘n stick

UV degradation of exposed rubberized asphalt Repair of Exterior Wall Systems Flashings

Problematic

Preferred Repair of Exterior Wall Systems Flashings

Butyl based flashing system EPDM based flashing system Repair of Exterior Wall Systems Flashings

Flashing interface and termination detailing Repair of Exterior Wall Systems Flashings Repair of Exterior Wall Systems Flashings

. Water that enters masonry above parapet can flow into parapet and adjacent roof construction. . Parapet flashing must be designed to direct water to the drainage system on both sides of the parapet. . Integrate moisture barrier behind facade cladding with flashing at the top of the parapet. Repair of Exterior Wall Systems Flashings Repair of Exterior Wall Systems Flashings

Parapet / wall interface detailing Repair of Exterior Wall Systems Flashings / Air Barrier

Flashing & air barrier repair detailing Repair of Exterior Wall Systems Air Barrier / Insulation / Vapor Retarder

. Cold “drafty” work area. . Repairs performed to establish continuity in air barrier, insulation, & vapor retarder. Building Envelope Resources

CCFM . Members / Affiliates / Website Forum Design Guides / Standards / Codes . Whole Building Design Guide (WBDG) . American National Standards Institute (ANSI) . National Institute of Standards and Technology (NIST) . International Code Council (ICC) Building Consultants . Architects/Engineers Building Enclosure Council (BEC) . Local BEC Chapters

Building Envelope Resources Building Enclosure Councils (BEC)

. Established in 2004 by the Building Enclosure Technology and Environment Council (BETEC) of the National Institute of Building Sciences (NIBS) and the American Institute of Architects (AIA) . Group of over 3,000 affiliated architects, engineers, contractors, manufacturers and others . Promote the exchange of information on matters concerning building enclosures and related science . 25 local chapters . http://www.bec-national.org Building Envelope Resources Building Enclosure Councils (BEC) Course Evaluations In order to maintain high-quality learning experiences, please access the evaluation for this course by logging into CES Discovery and clicking on the Course Evaluation link on the left side of the page. Contact

Kevin A. Kalata, RA, SE WJE Wiss, Janney, Elstner Associates, Inc. Phone: 847-272-7400 x4416 E-mail: [email protected]

Questions ???