Design of Adhered Masonry Veneers for Multi-storey Buildings

Design of Adhered Masonry Veneers for Multi-storey Buildings Presented by Dr. Mark D. Hagel, PhD., P.Eng Executive Director at the Alberta Masonry Council

Mark Hagel PhD. in civil engineering, BSc. in civil engineering, BSc. in actuarial science & applied math.

Mark Hagel Technical Services Engineer

Mark Hagel Building Envelope / Structural Engineer at HY

St. Pancreas Station - London Casaloma - Toronto

Outline Review of adhered masonry veneers (natural stone, manufactured stone and thin brick veneers). Adhered stone bond test program. (The why behind AMC recommendations). Design and detailing of adhered stone and adhered thin brick veneers above 10 over wood-stud and steel-stud structural backings. Design and detailing of adhered stone and adhered thin brick veneers over exterior insulation.

Types of Stone

Natural Stone Sedimentary: Metamorphic: 1. Limestone 2. Sandstone 1. Marble 2. Quartz-based 3. Slate 1. Smooth 2. Machine Tooled 3. Split face / Rock face 4. Chat sawn / Shot sawn 1. Smooth 2. Machine Tooled Igneous: 1. Granite 2. Basalt 1. Sawn 2. Honed 3. Polish 4. Machined

Natural Stone Varying physical properties depending on type (limestone, sandstone, etc) Compressive strength Modulus of rupture Freeze-thaw tests

Manufactured Stone Stone fabricated from lightweight concrete or calcium silicate to replicate all forms and finishes of natural stone. More consistent physical properties than natural stone (standardized by ASTM- C1670).

Types of Installation of Thin Stone Modular or Individual Unit Modular Unit (Dry Stack) Individual Unit (Jointed)

Thin Brick Veneer Units Typically ¾ (19 mm) but can be 3/8 (10 mm) to 1 1/8 (31 mm) thick. Can be extruded and fired as thin brick or cut after firing from solid units. Product cost the same cost or more less expensive than full brick because manufacturing cost (either cutting or cost of firing) are equal or more. Labour may be less expensive with full brick as masons can lay full bed more quickly.

ADHERED Stone Veneer

Adhered Thin Stone Veneer Natural Stone

Adhered Thin Stone Veneer Manufactured

ADHERED Thin Brick

Adhered Thin Brick Veneer

Design Literature Available ASTM C1780 15, Standard Practice for Installation Methods for Adhered Manufactured Stone Masonry Veneer. ASTM C1670 15, Standard Specification for Adhered Manufactured Stone Masonry Veneer Units/. Brick Institute of America Thin Brick Veneer Tech note 28C/. CSA-A371-2004 Annex A (removed from 2014 edition).

AMC - Adhered Stone Bond Testing

Failure Modes in the Field : Setting Bed / Stone Unit Interface

Failure Modes in the Field : Setting Bed / Scratch Coat Interface

Shear Bond Test Setup

Shear Bond Test Type N Shear Bond Strength = 8.3 psi No useful information from this failure mode Shear Bond Strength = 14.0 psi Shear bond that should be the outcome of a ASTM-C482 Shear bond test

Shear Bond Test Type S Shear Bond Strength = 23.3 psi Shear Bond Strength = 23.1 psi

Shear Bond Test Polymer Modified Stone Veneer Mortar Matching Mortar Block Shear Bond Strength = 36.8 psi Shear Bond Strength = 33.4 psi

Shear Bond Test Thinset Mortar, Type N Mortar Block Shear Bond Strength = 78.7 psi Shear Bond Strength = 91.1 psi

Shear Bond Test Thinset Mortar, Structural Water Resistive Barrier, Type N Mortar Block Shear Bond Strength = 65.7 psi Shear Bond Strength = 79.6 psi

Shear Bond Test Thinset Mortar Water Barrier and Cement Board

Adhered Stone Testing Results To Date

Design of Adhered Stone Veneer Four Cases Stone trim (not a full wall, typically less than 6 in height i.e. corners, columns, or features). Walls 10 (3.2m) or less in height. Walls Greater than 10 in height. Adhered masonry veneers over exterior insulation.

Case 1 Stone Trim

CRU Adhered Stone Trim

Single Family Residence Adhered Stone Trim

Drystack Manufactured Stone or Natural Stone Veneers and Thin Brick Veneers Use pre-bagged Type S mortar for jointed or drystack applications. Drainmat optional. Low risk of water ingress and low risk of injury if debonding of units occurs.

Case 2-10 (3 m) Above Grade or Less

CRU Adhered Stone 10

Single Family Residence Adhered 10

Drystack Manufactured Stone or Natural Stone Veneers and Thin Brick Veneers Use pre-bagged Type S mortar or Polymer Modified Stone Veneer mortar for jointed or drystack applications. Drain mat recommended.

Case 3 - Walls over 10 (3 m) in Height

CRU Adhered Stone Above 10

Single Family Residence Adhered Stone Above 10

Movement Joints Above 10

Back-up Wall Deflection Structural engineers typically design this deflection, D for a limit of h/360 ( 3 / 8 in 10 feet). Brick Institute of America (BIA) Full bed brick veneer recommends h/480 to prevent cracking in brick veneer ( 1 / 4 in 10 feet). Direct adhered ceramic tile and thin brick design guide recommends deflection limit of h/600 i.e. ( 3 / 16 in 10 feet). D = h / 600

Drystack Adhered Stone Veneers

Drystack Manufactured Stone or Natural Stone Veneers and Thin Brick Veneers Use Laticrete Hi-bond Masonry Veneer Mortar, Flexbond exterior grade Modified Dry-set cement mortar or equivalent meeting all requirements of ANSI-A118.4 or ANSI-A118.15).

Drystack Manufactured Stone or Natural Stone Veneers and Thin Brick Veneers

Jointed Adhered Masonry Veneers

Natural And Manufactured Stone and Thin Brick Veneers If Grout bagging is used for filling joints this is essentially a drystack application: Use Laticrete Hi-bond Masonry Veneer Mortar, Flexbond exterior grade Modified Dry-set cement mortar or equivalent meeting all requirements of ANSI-A118.4 or ANSI-A118.15).

Grout-Bag Installation of Adhered Thin Stone

Installation of Adhered Thin Brick Grout Bagged

Adhered Masonry Veneer Installed Like Traditional Stone Tied Masonry

Individual Units (Jointed) - Traditional Installation Method With Pre-bagged Type S Mortar and Ties

Replicate Traditional Composite Stone Wall Mechanical Anchorage

Adhered Stone Installed Like Traditional Stone Masonry The ties should help better anchor the veneer to the wall. However, testing is still underway to conclude that this is an adequate substitute for modified dry-set cement mortars (thinset mortars). Until further research confirms, installations above 20 recommend to use thinset mortars.

Replicate Traditional Composite Stone Wall Mechanical Anchorage

Mechanical Anchorage Of Thin Brick

Mechanical Anchorage of Adhered Thin Brick Modular Panels Corner Detail

Mechanical Anchorage of Adhered Thin Brick Modular Panel with Built-in Drainage

Mechanical Anchorage of Adhered Thin Brick Great for interior applications can get much more consistent mortar joints more easily. May not be best suited for exterior applications: 1. Steel and aluminum are thermal bridges with high thermal transmittance. 2. The light gauge metals can warp with temperature fluctuations referred to as oil canning. 3. The mill galvanized light gauge steel is not that corrosion resistant and the thin gauge steel is not well protected.

Installation of Thin Stone Veneer Over Rigid Insulation

Building Stone Institute (BSI) Rigid foam board cannot transfer the weight of the adhered stone veneer directly to the stud backup or foundation. The thicker the layer of foam, the more extreme the bending component will be. If such an installation cannot be avoided, consult an engineer to design appropriate anchors in order to avoid sagging or racking that can produce cracks in the veneer.

Adhered Masonry Veneers Over Exterior Insulation Long Fasteners

Wood Stud Backup Wall

Adhered Masonry Veneers Over Exterior Insulation Less Than 1-½ Long Fasteners

Steel Stud Backup Wall

Adhered Masonry Veneers Over Exterior Insulation Greater Than 1-½ Long Fasteners

Adhered Masonry Veneers over Exterior Insulation Greater Than 1-½ Long Fasteners

Adhered Masonry Veneers Over Exterior Insulation Greater Than 1-½ Long Fasteners

Adhered Masonry Veneers Over Exterior Insulation On Z-bars

Adhered Masonry Veneers Over Exterior Insulation Greater Than 1-½ Z-bars

Insulation Embedded Thin Masonry Veneers

Insulation Embedded Thin Masonry Veneers Ideal for thin clay brick, concrete brick or concrete masonry units or jointed random ashlar manufactured stone. Less ideal for drystack manufactured stone.

Insulation Embedded Thin Masonry Veneers Provides approximately R12. Drained both back and front side. Mechanically fastened with stainless steel ties. Shelf angle at base for extra support.

Insulation Embedded Stone Veneer Jointed Random Ashlar Simulated Drystack

Insulation Embedded Thin Brick Veneers

Insulation Embedded Thin Concrete Brick Veneers

Insulation Embedded Thin Concrete Masonry

AMC Design Aids

Design Aids Architects and Architectural Technologists 2D and 3D details Sample specifications Fire rating Tables STC ratings for block

Design Aids Engineers and Engineering Technologists 2D and 3D details structural details. Weblink to MASS software. EXCEL design Sheets for engineers available on request (tie design, shelf angle design, column / pilaster design, wall design.

Design Aids Adhered Stone Details http://albertamasonrycouncil.ca/architects

Design Aids R-Value Calculator

About AMC

Alberta Masonry Council To improve the longevity of architecture in Alberta through the aesthetic and stable appeal of masonry design.

Masonry Products are Green Building Materials Cement products reduce green house gases - they absorb carbon dioxide (CO 2 )over time. Manufactured stone products, mortar, scratch coat and cement boards all absorb CO 2 over their service life.

Masonry Products are Green Building Materials Masonry products are also modular and very recyclable. They produce less construction waste for land fills and are cradle - cradle NOT cradle to grave.

AMC Supplier Members