MASONRY DETAILING SCHOOL OF ARCHITECTURE AND PLANNING: MIT. Shelf Angles. Image by MIT OCW.

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1 Shelf Angles Image by MIT OCW.

2 Flashing Single Wythe Walls Image by MIT OCW.

3 Flashing with Shear Transfer Image by MIT OCW.

4 Flashing Reinforced Wall Image by MIT OCW.

5 End Dams

6 Flashing Laps 6

7 Drainage Materials

8 Weep Holes

9 Weep Tubes

10 Vent Weep Holes

11 Rope Wicks

12 Flashing Materials Sheet Metal Composites Plastic and Rubber Compounds

13 Sheet Metals Material Advantages Disadvantages Stainless Steel Durable, non staining Hard to solder and form Cold-Rolled Copper Durable Damaged by excessive flexing and can stain Galvanized Steel Easy to paint and durable Difficult to solder, corrodes early in acidic and salty air

14 Composites Material Lead-coated copper Copper laminates Advantages Flexible, durable, nonstaining Easy to form Disadvantages Difficult to solder, damaged by excessive flexing, metal drip edge suggested Degrades in UV light, more easily torn than metal

15 Plastics and Rubber Compounds Material Advantages Disadvantages EPDM Flexible, easy to form, nonstaining Aesthetics if not used with a metal drip edge, full support recommended Rubberized asphalt PVC Fully adhered, separate lap adhesive not needed, self healing, flexible, easy to form and join Easy to form and join, nonstaining, low cost Full support required, degrades in UV light, metal drip edge required Easily damaged, full support required, metal drip edge required, questionable durability

16 Bldg felt and poly sheeting

17 Bldg felt and poly sheeting

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

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

20 Coating Types Colorless Coatings Paints

21 Colorless Coatings Penetrating Silanes Siloxanes Film-forming Acrylics Stearates

22 Coating Types Paints Cement based Latex Alkyd Oil-based Paints

23 Differential Movement Movements Temperature Movement Moisture Movement Elastic Deformation Movement Joints Design Placement

24 Causes of Cracking Differential Movement Restraint Settlement Elastic Deformations Creep

25 Types of Movement

26 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

27 Moisture Movement Brick - irreversible expansion Concrete masonry drying shrinkage and carbonation

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

29 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

30 Types of Expansion Joints (Details) Premolded Foam Pad Sealant and Backer Rod (A) Sealant and Backer Rod (B) Copper Waterstop Neoprene Pad Sealant and Backer Rod (C) Sealant and Backer Rod (D) Image by MIT OCW.

31 Expansion Joint

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

33 Expansion Joints at Corners (A) L 2 L 1 Expansion Joints L 1 + L 2 < Typical Spacing Between Expansion Joints L 1 or L 2 = 10 Ft Maximum (B) Image by MIT OCW.

34 Horizontal Expansion Joint Image by MIT OCW.

35 False Horizontal EJ

36 Hiding Expansion Joints

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

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

39 Pre-formed Gasket

40 Formed Paper (also known as Michigan Joint)

41 Special Shape Unit

42 Joint Reinforcement at CJ

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

44 Control Joint Locations

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

46 Empirical Control Joint Criteria Spacing for above grade exposed concrete masonry walls Distance between joints is the lesser of: Length to height ratio or Notes: 1 ½ 25 feet Based on horizontal reinforcement of in. 2 /ft Applies to both Type I and Type II units Can be modified based on local experience

47 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 A s /A n Notes: A s = cross-sectional area of steel, in 2 /ft (mm 2 /m) A n = net cross-sectional area of masonry, in 2 /ft (mm 2 /m)

48 Engineered Crack Control Criteria (cont.) Notes: Need not apply if A s /A n > see Table 4. See Table 3 for A s /A n = 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.

49 Wall thick in. Table 3 Maximum Spacing of Hor. Reinf. for A > A 1 s n Maximum spacing of horizontal reinforcement, in. (mm) Reinforcement size #5 #4 #3 4x 3/16 4 x 8 gage 4 x 9 gage 2x 3/16 Ungrouted or partially grouted walls 2 x 8 gage 2 x 9 gage A n includes cross-sectional area of grout in bond beams.

50 Brick and Block Together Align Expansion Joints and Control Joints

51 Bond Breaks Use to separate bands of different masonry types