CHAPTER 14 Wall Systems Objectives Describe different types

CHAPTER 14 Wall Systems

Objectives • Describe different types of masonry wall systems. • Explain the use of ties, flashing, weep holes, lintels, sills, jambs, and expansion joints in masonry wall systems. • Explain the effects of moisture condensation in masonry walls and the methods used to resist condensation. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Objectives (Cont. ) • Describe construction procedures for thin brick veneer, including thin bed set, thick bed set, and precast panels. • Explain the design, function, and construction of arches. • Describe the joints used for movement in masonry. • Understand the function of caps and copings. • Install a retaining wall. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Masonry Walls • • • Single-wythe or multiple-wythe Reinforced or unreinforced Provide excellent structural performance Easily maintained and attractive Energy efficient due to high thermal mass Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Energy Codes • Most energy codes specify U-values – Heat flow through a building product based on difference between external and internal temperatures – R-value is thermal resistance of heat loss through a building product – R = 1/U Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Solid Masonry Walls • Loadbearing or nonloadbearing Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

6″ Masonry Walls with SCR brick • Nominal thickness of 2 2/3″ produces 16″ in six courses • Nominal 6″ wide and 12″ long Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Four-Inch RBM Curtain and Panel Walls • Exterior nonloadbearing walls • Curtain walls – Not wholly supported at each story • Panel walls – Supported at each story and self-supporting between stories • Both types must be able to resist lateral forces Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Design of Four-Inch Walls • Partially reinforced • Ladder- or truss-type reinforcement • Drainage space on inside of wall • Expansion joints Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Hollow Masonry Walls • Walls built using solid or hollow masonry units • Separated to form inner and outer wall • Two types – Cavity walls – Masonry bonded walls Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Cavity Walls • Widely used in low- and high-rise buildings • Superior rain penetration resistance, thermal capabilities, sound transmission, and fire resistance • Continuous air space 2″ to 3″ wide Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Construction of Cavity Walls • Exterior wythe – Usually a nominal 4″ thick – Solid or hollow brick • Interior wythe – 4″, 6″, or 8″ thick – Brick, structural clay tile, or hollow or solid concrete masonry units Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Cavity • Air space has insulation value and can be filled with insulation material for added reduction of heat transfer • Acts as a barrier to moisture • Must be kept free of mortar droppings Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Weep Holes • Required at bottom of cavity wall • Mortar opening creates void for moisture inside wall cavity to exit • Located immediately above flashing Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Flashing • Thin, impervious material • Usually made of metal • Keeps any moisture that might collect in cavity away from inner wall Portland Cement Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Insulation • Rigid boards installed horizontally within air space against cavity face of backup wythe • Granular fill is usually poured directly into cavity from bag or from hopper Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Bonding • Adjacent wythes tied together with corrosion-resistant 3/16″ diameter steel or metal ties • Ties in alternate courses should be staggered • End of ties should be bent to 90° angles • Additional ties needed at openings Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Flashing • Diverts moisture out of cavity through weep holes • Continuous flashing at bottom of cavity and wherever cavity is interrupted • Over unprotected wall openings • At window sills, parapet walls, and spandrels Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Weep Holes • Must be provided wherever flashing is used • Located in joints of outer wythe immediately above flashing • Spacing is approximately 2′ O. C maximum – Weep holes using wick material should be 16″ O. C. maximum Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Expansion Joints • Movement of outer brick wythe is greater than that in solid or composite walls • Expansion joints are recommended through outer wythe on each side of external corner where walls are 50′ or more in length Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Hollow Masonry Bonded Walls • Used as foundation and exterior loadbearing walls • Not resistant to high moisture Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Anchored Veneered Walls • Brick and stone masonry facing veneer • Veneer is attached, but not bonded to, backing • Veneer does not act structurally with rest of wall Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Anchored Brick Veneer Construction • Nominal 3″ or 4″ thick exterior brick wythe is anchored to backing system with metal ties • Clear air space between veneer and backing • Wood frame, steel frame, concrete, or masonry backing system • Facing of masonry units or other weather-resisting, noncombustible materials Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Moisture Resistance • Brick veneer wall assemblies are drainage-type walls that resist rain penetration • Flashing and weep holes work with air space to resist moisture penetration • Brick veneer with wood or metal frame backing is usually built with minimum 1″ air space Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Brick Veneer Foundations • Brick veneer on frame backing transfers weight of veneer to foundation • Foundation brick ledge supporting brick veneer should be at least equal to total thickness of wall assembly • Foundations must extend beneath frost line Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Masonry Wall Ties • Noncorrosive metal ties – One tie for every 2 2/3 sq ft of wall area – Maximum spacing of 24″ O. C. in either direction • Nail must be located within 5/8″ of bend in tie Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Wire Ties • Must be embedded at least 5/8″ into bed joint from air space • At least 5/8″ cover of mortar to exposed face • Corrugated ties must penetrate to at least half the veneer thickness and have at least 5/8″ mortar cover Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Flashing and Weep Holes • Position above grade – As close as possible to bottom of wall – As close as possible above openings and below sills • Weep holes should be in head joints directly above flashing • Weep hole spacing – No more than 24″ O. C. for holes in which mortar has been completely removed – Maximum of 16″ O. C. for holes with wicking material Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Lintels • Brick veneer backed by wood or metal frame must be supported by lintels over openings • Lintel materials – – – Loose steel Stone Precast Concrete Cast stone Reinforced brick Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Expansion Joints • May be needed to allow for horizontal movement • Required in brick veneer when there are – Long walls – Walls with returns – Large openings Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Composite Walls • Two walls bonded together with masonry or wire ties • Vertical collar joint (narrow space between facing and backup units) prevents passage of water Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Building an 8″ Composite Wall • First course of facing may be either headers or stretchers • All facing courses are laid in a full mortar bed with head joints completely filled • Facing headers are laid every seventh course • Mortar extruded on backside should be cut flush with trowel before it hardens Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Building an 8″ Composite Wall (Cont. ) • Wythes can be bonded across collar joint by parging backside of facing Portland Cement Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

12″ Composite Wall • Facing header course is laid overlapping the header block • Header block can be laid with recessed notch up or down Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Resisting Moisture Condensation • Water affects many building materials • Condensation can be decreased through ventilation or dehumidification • Mechanical devices and heat exchangers remove moisture-laden air Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Reinforced Masonry Walls • Steel reinforcement embedded in masonry units • Structurally bonded by grout core – Grouting techniques vary • Full bed joints are used Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Reinforcing Masonry Walls • Maximum spacing of principal reinforcement should not exceed 48″ • Primary use of steel reinforcement is in vertical members, lintels, and bond beams Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Retaining Walls • Reinforced masonry • Two common designs – Gravity – Cantilever-Type Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Grouted Masonry Walls • Single- or multi-wythe • Similar to reinforced masonry walls but without reinforcements • Grout is added to core in loadbearing masonry walls to provide added strength • Other uses include filling bond beams and collar joint in two-wythe walls Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Thin Brick Veneer • Thin brick units approximately 1/2″ to 1″ thick • Give appearance of conventional brick wall • Most common face size has nominal dimensions of 2 2/3″ × 8″ • Adhered veneer Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Thin Brick Veneer Classifications • Thin bed set Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Thin Brick Veneer Classifications (Cont. ) • Thick bed set Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Thin Brick Faced Precast Panels • Forming table creates size and shape of wall panel • Thin brick composes exterior face of panel, becomes bonded and embedded into panel when concrete mix is poured into form • Constructed indoors and delivered to site Gage Brothers in Sioux Falls, SD Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Chases and Recesses • Horizontal or vertical spaces for plumbing, heating ducts, electrical wiring, etc. • Chases are located inside of wall and are from 4″ to 12″ in width • Recesses are limited to 1/3 of wall thickness Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Lintels • Structural member placed wall opening to support loads above – Steel lintels should be supported on either side of opening for at least 4″ – Reinforced concrete lintels should have a minimum bearing of at least 8″ at each end – Longer lintels should have greater bearing surfaces at ends Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Types of Lintels Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Detailed Brick Masonry Lintel • Brick masonry lintel with stirrups Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Movement at Lintels • Slight movement occurs at location of lintels • Control joints are often located at ends • Noncorroding metal plate is placed under ends where control joints occur to prevent uncontrolled cracking • Full bed of mortar should be used over plate Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Arches • Masonry units span an opening by transferring vertical loads laterally to adjacent masonry units, and thus to abutments Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Arch Terminology Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Arch Classifications • Arches are normally classified by: – Curve of intrados – Function, shape, style • Arches are also classified as major and minor Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Types of Arches Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Types of Arches (Cont. ) Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Function of Arches • Compression stresses are distributed through arch • Weight is diverted to abutments • Some may require steel reinforcements Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Arch Design • Odd number of units are used so keystone falls at center of crown • Arch voussoirs are usually in radial orientation • Different shapes and sizes of brick selected based on arch type, dimension, and desired appearance Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Arch Spans • Short spans – Tapered brick is recommended to avoid wide mortar joints at extrados • Larger spans – Requires less taper of the voussoirs – Formed with rectangular brick and tapered mortar joints – Mortar joint should be between 1/8″ and 3/4″ Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Arch Depth • Dimension of arch at skewback that is perpendicular to arch axis, except in jack arches • Depends on size and orientation of brick used • Usually a multiple of the brick’s width • Arch depth should increase with increasing arch span Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Brick Masonry Arch Construction • Two methods – Special shapes and uniform joint thickness – Units of uniform thickness with varying joint thickness • All mortar joints must be completely filled Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Centering for Arches • Temporary shoring supports masonry • Centering is usually made from wood Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Jack Arch Construction • Supported by steel if opening is over 2′ wide • Steel must be bent to the camber • Each joint should be same width as entire length of joint • End joints are horizontal to radius of arch Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Segmental Arch Construction • Number of courses is determined by length of extrados • Size of brick is determined by length of intrados • Rise should be 1/6, 1/8, 1/10, or 1/12 of span Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Window and Door Details • Details are necessary for mason to plan ahead • Relationships between head, jambs, and sill to masonry wall Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Sills • Channel water away from a building • Single or multiple units • Built in place or prefabricated • Made of cut stone, brick, concrete, or metal Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Joints for Movement in Masonry • Volume changes in masonry material result in movement • Joints allow for movement to occur and to prevent cracks • Types – – Expansion joints Control joints Building expansion joints Construction joints Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Expansion Joints • Separate brick masonry into segments • Prevent cracking due to changes in temperature, moisture expansion, elastic deformation, and creep • Horizontal or vertical • Located so as not to compromise structural integrity Brick Industry Association Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Control Joint • Creates a plane of weakness in concrete masonry to control location of cracks • Vertical opening through concrete masonry wythe • Must be located so structural integrity of concrete masonry is not affected Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Building Expansion (Isolation) Joint • Divides building into separate sections so stresses developed in one section do not affect integrity of remainder of structure • Through-the-building joint allows adjoining parts of building to move freely from one another Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Construction (Cold) Joint • Used where masonry work is interrupted • Mason terminates work at a vertical plane and then continues laying brick until that section of wall is complete • Next section of wall begins at construction joint • Located where least likely to impair strength Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Bond Breaks • Prevent cracks due to differences in expansion and contraction rates of materials • Building paper or flashing separate two surfaces of masonry material • Used between floor slabs and foundations • Allow each element to move somewhat independently while providing support Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Brick Masonry Soffits • • Enclose a building Provide attractive appearance Large soffits requires expensive forming and shoring Brick masonry soffit may be more efficient for small soffit area • Usually reinforced and grouted Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Stone Quoins • Large square stones used at corners and around openings of building for ornamental purposes • Height is odd number of brick courses • Length is equal to one or more units used in wall Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Garden Walls • Freestanding structures – Straight walls – Pier and panel walls – Serpentine walls • Can be perforated Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Straight Walls • Masonry texture and color give character • Thickness provides lateral stability against wind and impact loads • Different copings Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Pier and Panel Walls • Series of relatively thin panels 4′ thick, braced by masonry piers • Easy to build and economical • Ideal for uneven terrain • Foundations are required only for piers Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Serpentine Walls • Serpentine shape provides lateral strength so wall can be built 4″ thick • Radius of curvature no more than twice height above grade • Depth no less than 1/2 of height Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Caps and Copings • Channel water away from building – Cap is covering within height of wall – Coping is covering at top of wall • Single or multiple units • Tops slope in one direction or both directions • Made of brick, precast or cast-in-place concrete, stone, metal, or terra cotta Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Corbels • Shelf or ledge formed by projecting successive courses of masonry out from face of wall • Used to achieve a particular appearance or to provide structural support • Horizontal projection should not exceed 1/2 thickness of wall or veneer • Projection of single course should not exceed 1/2 of unit height or 1/3 of unit bed depth Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Racking • Masonry in which successive courses are stepped back from face of wall • When racking back to achieve desired dimensions, make sure cores of units are not exposed Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Segmental Retaining Walls (SRW) and Hardscape • Constructed of highstrength concrete blocks or units made for dry stacking • SRW blocks are used to build retaining walls • Hardscape is intended for decorative purposes Anchor Wall Systems, Inc. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Retaining Wall Products • Some have locking lip on lower back edge • Prevent forward movement exerted by earth pressures • Straight and beveled front units with uniform or tapered widths Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Retaining Wall Installation • Prior to construction, prepare a layout plan that considers topography, drainage patterns, soil conditions, and local code restrictions Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.