1. A Technical Review of Proper Masonry Detailing
Matthew A. Dettman, P.E.

2. Overview Water Penetration Resistance Differential Movement
Wall Systems
Flashing and Weep holes
Coatings
Differential Movement
Cracking
Movement Joints

3. Problems related to water penetration
Water entry into interior
Efflorescence
Spalling
Corrosion
Reduced insulating capacity
Staining / Mold / Mildew

4. Keys to Providing Water Penetration Resistance
Quality Materials
Good Construction
Proper detailing
Maintenance

5. Keys to Providing Water Penetration Resistance
Quality Materials
Good Construction
Proper detailing
Maintenance

6. Three Basic Wall Types
Drainage Wall
Barrier Wall
Single Wythe Wall

7. Drainage Wall

8. Drainage Wall
Water travels down back side of outer wythe, collected on flashing, and channeled to exterior through weep holes
Examples:
Cavity walls
Masonry veneer walls
Rain screen walls

9. Drainage Walls Requirements
2 to 4 ½ inch clear cavity
Flashing and weep holes to channel out excessive water

10. Rain Screen Wall Equalizes pressure within cavity
Vents at top and bottom of wall or panel
Flashing and weep holes
Compartmentalized
Allows for ventilation and evaporation

11. Barrier Wall
Collar joint between wythes acts a barrier to moisture along with the thickness of the wall
Examples
Brick and Block Composite Wall

12. Barrier Wall Voids allow water penetration
Must be filled solid with mortar or grout

13. Single Wythe Walls

14. Single Wythe Masonry units with coating or integral water repellent
Mortar with integral water repellent
Through-wall flashing
Weep Holes
Vents

15. Flashing Details
Locations
Placement

16. Flashing Locations base of wall sills heads of windows at shelf angles
copings
lower wall/ higher roof intersection
other discontinuities in air space

21. Good Flashing Detail

22. Poor Detail

23. Drip Edge

25. SS Drip Edge

26. Shelf Angles

27. Flashing Single Wythe Walls

28. Flashing with Shear Transfer

29. Flashing Reinforced Wall

30. End Dams

31. Flashing Laps

32. Drainage Materials

33. Weep Holes

34. Weep Tubes

35. Vent Weep Holes

36. Rope Wicks

37. Flashing Materials
Sheet Metal
Composites
Plastic and Rubber
Compounds

38. Sheet Metals Material Advantages Disadvantages Hard to solder and form
Damaged by excessive flexing and can stain
Difficult to solder, corrodes early in acidic and salty air
Stainless Steel
Cold-Rolled Copper
Galvanized Steel
Durable, non staining
Durable
Easy to paint and durable
Stainless steel is technically any of a large and complex group of corrosion resistant iron chromium alloys possessing excellent weather and chemical resisting properties. Preformed sections must be properly sized so that modification on the site is minimal. Typical: Type 304 stainless steel with a minimum thickness of in. (0.25 mm). Lapped sections must be soldered. Stainless steel drip edges used in combination with other flashing materials also works well.
Copper is a non-ferrous metal with good ductility. Like stainless steel, it also possesses excellent weather and chemical resistant properties. Preformed sections are easier to modify in the field. Be careful of green patina stains!
Galvanized steel is less expensive than stainless, but is more subject to attack from salts and acids. The galvanized coating may also crack at bends, lowering the corrosion resistance. As with stainless, hard to solder laps.

39. Composites Material Advantages Disadvantages
Difficult to solder, damaged by excessive flexing, metal drip edge suggested
Degrades in UV light, more easily torn than metal
Lead-coated copper
Copper laminates
Flexible, durable, non-staining
Easy to form
Some companies provide flashings that have combined metals and plastics.
Copper composites are popular since they combine the durability and malleability of copper with non-staining characteristics of the plastic coating.
Composites containing aluminum should be avoided.

40. Plastics and Rubber Compounds
Material
Advantages
Disadvantages
Flexible, easy to form, non-staining
Fully adhered, separate lap adhesive not needed, self healing, flexible, easy to form and join
Easy to form and join, non-staining, low cost
Aesthetics if not used with a metal drip edge, full support recommended
Full support required, degrades in UV light, metal drip edge required
Easily damaged, full support required, metal drip edge required, questionable durability
EPDM
Rubberized asphalt
PVC
Plastics are categorized as polymeric materials of large molecular weight, usually polyvinyl chloride (PVC) or polyethylene. Manufacturers of plastic flashings should be consulted for documentation establishing the longevity of the plastic in a caustic environment (pH = 12.5 to 13.5), the composition of the plastic, ease of working at temperatures ranging from 20 to 100°F and ability to withstand exposure to ultraviolet light.
Ethylene Propylene Diene Monomer (EPDM) is a synthetic rubber that is used as a single ply roofing membrane as well as flashing. It has better low temperature performance than PVC and will not embrittle. It offers ultraviolet light and ozone resistance and can be left exposed.
Self-adhering, rubberized asphalt membranes consist of a composite of flexible plastic film for puncture and tear resistance combined with a rubberized asphalt adhesive layer. This material adheres to itself, requiring less effort to seal laps or corners which speeds installation. It also self-adhered to the substrate which prevents water form migrating under the flashing and is self-healing in the event of punctures. However, it should not be applied to damp, dirty, or dusty surfaces and has a typical lower limit installation temperature of 25 °F. Because it degrades in the presence of extended UV exposure, it should not be left exposed and requires a metal drip edge.

41. Bldg felt and poly sheeting

42. Colorless Coatings Used for a variety of reasons
Recommended for Concrete Masonry
Questionable for Clay Masonry

43. Possible Dangers Water can still penetrate Could cause spalling
If efflorescence occurs under coating, it may be impossible to remove
Recoating will be necessary

44. Coating Types
Colorless Coatings
Paints

45. Colorless Coatings Penetrating Film-forming Silanes Siloxanes Acrylics
Stearates

46. Coating Types
Paints
Cement based
Latex
Alkyd
Oil-based Paints

47. Differential Movement
Movements
Temperature Movement
Moisture Movement
Elastic Deformation
Movement Joints
Design
Placement

48. Causes of Cracking Differential Movement Restraint Settlement
Elastic Deformations
Creep

49. Types of Movement

50. Temperature Movement Coefficient of Thermal Expansion
Brick = 3.6 x 10-6
Concrete Masonry = 4.3 x 10-6
Aluminum = 12.8 x 10-6
Steel = 6.5 x 10-6

51. Moisture Movement Brick - irreversible expansion
Concrete masonry – drying shrinkage and carbonation

52. Types of Movement Joints
Expansion Joint - Brick Masonry
Control Joint - Concrete Masonry
Building Joint - Structures

53. Expansion Joint Used in Clay Masonry
Used to separate brick into sections so cracking will not occur
Horizontal / Vertical
Entire joint is unobstructed and formed from a highly elastic, continuous material

54. Types of Expansion Joints (Details)

55. Expansion Joint

56. Typical Spacing and Locations of Expansion Joints
Long Walls
Corners
Setbacks & Offsets
Parapet walls
Beneath shelf angles

57. Expansion Joints at Corners

58. Horizontal Expansion Joint

59. False Horizontal EJ

60. Hiding Expansion Joints

61. Control Joint Used in Concrete Masonry
Relieve horizontal tensile stresses
Reduce restraint and permit longitudinal movement
Separate dissimilar materials

62. Types of Control Joints
Pre-formed gasket
Formed paper
Special shape units

63. Pre-formed Gasket

64. Formed Paper (also known as Michigan Joint)

65. Special Shape Unit

66. Joint Reinforcement at CJ

67. Bond Beams
Do not cut bond beam reinforcement unless specifically indicated on the plans

68. Control Joint Locations

69. Control Joint Spacing Two methods: Empirical Engineered
based on historical performance
Engineered
based on a crack control coefficient

70. Empirical Control Joint Criteria
Spacing for above grade exposed concrete masonry walls
Distance between joints is the lesser of:
Length to height ratio or
1 ½ feet
Notes:
Based on horizontal reinforcement of in.2/ft
Applies to both Type I and Type II units
Can be modified based on local experience

71. Engineered Crack Control Criteria
Criteria for Controlling Cracking in Reinforced Concrete Masonry Walls
Crack Control Coefficient
in./in. (mm/mm)
________________ __________ __________ ___
Maximum wall _length, ft (m)_________25 (7.62)__20 (6.10)
panel dimensions_ length/height ratio_ _____2 ½ ______2___
Min. horizontal reinf. ratio As/An
Notes:
As = cross-sectional area of steel, in2/ft (mm2/m)
An = net cross-sectional area of masonry, in2/ft (mm2/m)

72. Engineered Crack Control Criteria (cont.)
Notes:
Need not apply if As/An > see Table 4.
See Table 3 for As/An = minimum requirement.
Minimum reinforcement ratio need not apply if length is < ½ maximum length shown in table.
CCC’s less than may be available in some areas and spacing should be adjusted accordingly.
Control joint spacing may be adjusted up or down based on local experience.

73. Table 3—Maximum Spacing of Hor. Reinf. for A > 0.0007A1
Wall
thick
in.
Maximum spacing of horizontal reinforcement, in. (mm)
Reinforcement size #5 #4 #3 4x
3/16
4 x 8
gage
4 x 9 2x
2 x 8
2 x 9
Ungrouted or partially grouted walls 6
144
128 64 72 56 48 40 24 8 96 32 16 10
136 80 12
120
1. A
includes cross-sectional area of grout in bond beams.

74. Brick and Block Together
Align Expansion Joints and Control Joints

75. Bond Breaks
Use to separate bands of different masonry types