Masonry Veneer Curtain Walls Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 John Wiley & Sons. All rights reserved

Masonry Veneer Curtain Walls

Fundamentals of Building Construction, Materials & Methods, 5th EditionCopyright © 2009 John Wiley & Sons. All rights reserved.

20 Cladding With Masonry and Concrete

Construction Sequence and Essential Elements• Shelf angle is installed on

the structural frame• Soft joint or horizontal

expansion joint is maintained below the shelf angle

• Flashing is installed over the shelf angle and it should project by 1” (25mm) and should be bent downward at a 450 angle.

• Flashing is tucked into the backup wall or over the slab



Construction Sequence and Essential Elements• A back up wall of concrete

or steel studs covered with water resistant sheathing panels of gypsum or cementitious material is constructed

• A weather barrier and air barrier are installed over the backup wall followed by insulation

• Brick masonry veneer wythe is erected brick by brick or stone by stone with conventional mortar and tied to the backup wall by ties



Shelf Angles & Horizontal Joints1. Shelf angle attached to

a concrete frame with an insert cast into the slab

2. Shelf angle attached to a steel frame using clip angle and shim plate and wedge shaped slot for adjustments

3. Soft joint or horizontal expansion joint is shown in the typical detail of brick veneer cavity wall with concrete block backup wall. Joint is designed to absorb column creep, brick expansion, spandrel beam deflection and dimensional tolerances



3

2

1

Vertical Joints• Masonry curtain walls

must be divided vertically by movement joints called vertical expansion joints to allow the frame and the masonry cladding to expand and contract independently of one another



Backup Walls and Structural Frames• Backup walls may be

of concrete or steel studs

• Masonry cavity wall may be installed on buildings with structural frames of concrete or steel.



Detail and Completed Building – Brick Veneer With Steel Stud Backup With Steel

Structural Frame

Prefabricated Reinforced Brick Panel Curtain Walls1. Masons construct

the panels while working comfortably at ground level in a factory. Horizontal and vertical reinforcements are laid as required

2. Panels are self-rigid and need no structural backup



1

2

Prefabricated Reinforced Brick Panel Curtain Walls• These panels can be

fastened to the building in much the same way as precast panels

• A steel stud backup wall is required to carry thermal insulation, electrical wiring, and an interior finish layer but has no structural role



Stone Curtain Walls



Stone Panels Mounted on a Steel Subframe• Grid-system-supported stone

cladding– Vertical members are erected

first to transmit gravity and wind loads

– The horizontal members are aluminum shapes that engage in slots in upper and lower edge of each stone

– Backer rods and sealants fill the joints between the stone

– Non structural back-up wall of steel studs and gypsum sheathing is constructed within the frame of the building to provide air barrier, insulation, electrical wiring and interior finishes

– Sealant joints are the weak link for water penetrationFundamentals of Building Construction, Materials & Methods,

5th EditionCopyright © 2009 John Wiley & Sons. All rights reserved.

Stone Curtain Walls

• Stone cladding installation in progress1. The reddish orange

material is the weather-resistive membrane. If properly sealed at its seams and edges, this product is also capable of acting as an air barrier

2. Vertical lines struck on the membrane mark the locations of metal studs in the backup wall. Anchor fasteners must be located over these lines, so that they engage the studs


Stone Curtain Walls

Stone Panels and Extruded Aluminum Supports

1

222

• Anchor close-up. Note the resilient cushioning material where the anchor is slotted into the stone

• This image also illustrates several construction deficiencies:1. The fasteners appear

to be offset so far to one side of the anchor and its shims that the clip may not remain stable when fully loaded by the weight of the next panel above

2. The continuity of the weather-resistive/air barrier has been interrupted by electrical conduit routed in the space behind the stone


Stone Curtain Walls

Stone Panels and Extruded Aluminum Supports

2

1

Monolithic Stone Cladding Panels• The panels are

fastened directly to the frame of the building

• The weight is transferred to two steel support plates by means of edge pockets that are cut into both sides at the stone mill

• Each panel is stabilized by a steel angle strut

• Joints are closed with backer rod and sealant

• A non structural backup wall is required


Stone Curtain Walls

Stone Cladding on Steel Trusses• Sheets of stone are

combined into large prefabricated panels by mounting them on structural steel trusses

• Each truss is designed to carry wind loads and dead load of the stone to steel brackets that are used to attach the truss to the building frame

• This is a relatively costly system


Stone Curtain Walls

Posttensioned Limestone Spandrel Panels• Thick blocks of

limestone may be joined with adhesives into long spandrel panels and post-tensioned with strength steel tendons

• The assembly is self supporting between columns

• This is a relatively costly type of panel


Stone Curtain Walls

Very Thin Stone Facings• Extremely thin sheets of stone may

be stiffened with a structural backing such as a metal honeycomb and mounted as spandrel panels in in an aluminum mullion system

• Very thin sheets of stone may be used as facings for precast concrete curtain wall panels

• When specifying the thicknesss of stone for any exterior cladding application, the designer should work closely with stone supplier.

• Thin stones have been a cause of number of failures of cladding systems


Stone Curtain Walls

Precast Concrete Curtain Walls



Precast Concrete Aesthetics• Precast concrete

cladding panels can be conventionally reinforced and be prestressed

• They can come in variety of sizes and surface finishes, from glassy smooth to rough, exposed aggregates

• Ceramic tiles, thin bricks or stone facings may be attached to precast panels



Precast Concrete Manufacture of Sandwich Panel1. Ribbed surface finish

being applied to precast concrete before the concrete sets

2. Insulation can be incorporated into the precast concrete panel in a sandwich panel system



2

1

Typical Detail of Precast Concrete Curtain Wall• Precast on sitecast

concrete frame• Panels shown are full

story high containing a fixed window. Bottom half of one panel (1) and top half of the lower panel (2) are shown

• The reinforcing bars are omitted for clarity but outline of thermal insulation and interior finishes (3) on the interior is shown



1

2

3

Precast Concrete Cladding Installation• Precast concrete

spandrel panels and brick veneer column covers hung off of a cast-in-place concrete frame structure



Precast Concrete Cladding Installation • End view of a precast

concrete spandrel panel

• Two polyisocyanurate rigid foam insulation boards (1) are visible on the back of the panel.

• The slightly darker colored band of insulation (2), at slab level between the two insulation boards, is safing, intended to restrict the passage of smoke and fire between floors.



2

1

1

Glass-Fiber-Reinforced Concrete Curtain Walls - Fabrication• GFRC is a relatively new

cladding material• Its admixture of short

glass fibers provides enough tensile strength that no steel reinforcing is required

• Panel thickness and weight are about one quarter of those for precast

• They can be molded into variety of shapes

• The panels may be self-stiffened with GFRC ribs but the usual practice is to attach a welded frame of light gauge steel studs to the back of GFRC



Glass-Fiber-Reinforced Concrete Curtain Walls - Attachment1. GFRC panels can be

attached with a diagonal brace and downrigger

2. GFRC panels can be attached with angle with oversized hole

3. Steel rod anchors can flex to accommodate small amounts of movement between the facing and the frame



21

33

Glass-Fiber-Reinforced Concrete Curtain Walls – Joint Treatment• Edges of the GFRC

panels are flanged to provide surface for sealant at joints

• Edge of the GFRC panels at transition between components need to be designed for receiving membrane and cap flashing



Exterior Insulation and Finish Systems



EIFS – Essential Elements• Exterior insulation and

finish system (EIFS) consists of– Layer of plastic foam

insulation adhered or mechanically fastened to a backup wall

– A reinforcing mesh that is applied to the outer surface of the foam

– A base coat of a stucco like material which embed the mesh

– An exterior finish coat of a similar stucco like material that is troweled over the base coat



EIFS – Panelized System• EIFS can be

constructed in place over a backup of concrete masonry or steel studs

• EIFS can also be prefabricated

A. Steel studs are welded together to make a backup frame

B. Rigid sheathing is screwed to the frame and finished with EIFS

C. The finished panels are lifted and bolted to the building frame



EIFS – Drained Systems• EIFS typically is

designed as a barrier type system which has resulted in numerous cases of water damage in EIFS faced buildings

• EIFS producers now market water managed or water-drainage EIFS– These systems

utilize a layer of drainage matting behind the foam insulation that can capture water and conduct it to plastic flashings and weeps at the base of the walls



Future Directions in Masonry and Stone

Cladding



Need For Rainscreen Systems• Most masonry and concrete

cladding systems except brick veneer are barrier systems

• There is no well organized system of secondary drainage

• There are cavities behind these systems but are interrupted by framing and attachment components

• There have been isolated efforts to design true rain screen details for stone and concrete cladding systems but more research is needed


Future Directions in Masonry and Stone Cladding

MasterFormat Sections For Masonry and Concrete Cladding



CSI/CSC MASTERFORMAT SECTIONS FOR MASONRY AND CONCRETE CLADDING 03 40 00 PRECAST CONCRETE

03 45 00 Precast Architectural Concrete

Faced Architectural Precast Concrete

03 49 00 Glass-Fiber-Reinforced Concrete

04 20 00 UNIT MASONRY

04 21 00 Clay Unit Masonry

Brick Veneer Masonry

04 25 00 Unit Masonry Panels

Metal-Supported Unit Masonry Panels

04 40 00 STONE ASSEMBLIES

04 42 00 Exterior Stone Cladding

Grid-System-Supported Stone Cladding

Stone Panels for Curtain Walls

07 20 00 THERMAL PROTECTION

07 24 00 Exterior Insulation and Finish Systems

Polymer-Based Exterior Insulation and Finish System

Polymer-Modified Exterior Insulation and Finish System

Water-Drainage Exterior Insulation and Finish System

07 40 00 ROOFING AND SIDING PANELS

07 42 00 Wall Panels

Fabricated Wall Panel Assemblies

Documents

Masonry Veneer Curtain Walls Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 John Wiley & Sons. All rights reserved