Top Signs of Façade Problems How to See the Invisible Vision is the art of seeing things invisible Jonathan Swift NAREIM Home Page

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1 Top Signs of Façade Problems How to See the Invisible Vision is the art of seeing things invisible Jonathan Swift NAREIM Home Page Carolyn L. Searls

2 Outline How and Where to Look for the Invisible I. Top ten signs to look for to detect façade problems II. The prepurchase survey (and NDT methods) III. Current problems we re seeing in building materials and systems IV. Current problems we re seeing in the building process

3 I. Top 10 Signs of Façade Problems Water Leaks

4 10. Deteriorating Sky-facing Surfaces Look for Concrete or masonry parapets without metal copings Horizontal ledges without waterproofing Any horizontal surface with deteriorated joints, waterproofing or paint

5 9. Efflorescence and Water Stains Look for

6 8. Rust Stains

7 8. Rust Stains Look for Orange rust stains The source of the stains (the steel) The source of the water Expansion of rust product can cause spalls

8 7. Cracks Look for these normal shrinkage cracks

9 7. Cracks Look for these cracks indicative of problems Marble expansion Corrosion Thermal and moisture expansion; lack of support

10 7. Cracks Look for these cracks indicative of problems Corrosion of window lintels

11 7. Cracks Look for these cracks indicative of problems Seismic

12 7. Cracks Cause of the cracks The material wants to move but can t The material can t take the stress Moving or non-moving cracks?

13 6. Paint Failures Look for

14 5. Deteriorated Mortar Joints Look for Missing mortar, holes in mortar joints Cracks in mortar joints Separations between mortar and masonry units Underlying causes

15 4. Deteriorated Sealant Joints Look for Reversion Cohesion Failure Adhesion Failure

16 3. Deterioration of Window Systems Look for Gaps at gasket corners Hardened or failed sealants or gaskets Water streaks down interior vertical mullions Wet finishes below window sill Wet finishes above window (from floor above) Weep holes caulked over

17 2. Mold Look for Red, black or green mold Pink spots visible through vinyl wallpaper

18 1. Pieces Falling Off

19 1. Pieces Falling Off Look for subtle cracks can indicate delaminated pieces, ready to fall off Displaced elements Out-of-plane elements

20 The Biggest Problems Occur Where components of a building intersect

21 II. The Pre-purchase Survey Hoping to Uncover the Invisible Review drawings and specs, maintenance records, leak records Speak with building managers/engineers, occupants Visual survey from ground $$$ - Maintenance and repair costs Close-up visual survey NDT Investigative openings Water testing or other testing, as required

22 Pre-purchase survey Interview People who are familiar with the everyday behavior of the building Gather data on leaks, cracks, previous repairs or alterations Are any drawings available? Does the building leak every time it rains? Or only when it is windy? How long after the rain starts do leaks appear?

23 After the Visual Survey - Next Steps More detailed survey Larger sample size Close up inspection Selective disassembly Field and laboratory testing Appropriate water testing Analysis structural, hygrothermal Repair design & budgeting Options analysis

24 Pre-purchase survey Benefits of close up inspection

25 Southwest Museum Rope Access Condition Survey, Sounding, Petrographic Analysis of Plaster

26 Pre-purchase survey Benefits of inspection openings

27 Nondestructive Testing The value of inspection openings Open an area to visually or physically confirm the nondestructive test results (say, from GPR, pachometer, etc.) The value of a 2 nd nondestructive test method If openings are not possible or not valuable, it s good to have a 2 nd method to confirm the results of the 1 st Test results need to be interpreted (and may take some time) Data may be immediately available, but the significance may not With any test, understand what the test is really measuring

28 Your Most Important High Tech Tools

29 Borescope Photo credit: Michael Schuller Photo credit: Michael Schuller

30 Metal Detectors Eddy current induction Run over surface of masonry to identify metal reinforcement, anchors Many versions: pachometer, Ferroscan, Profometer

31 Ground-Penetrating Radar (GPR) Next best thing to physically seeing Produces a virtual picture through data on a screen Data requires interpretation by a trained operator Excellent for identifying: Location and depth of metal reinforcement Voids in masonry construction Presence of grout in CMU cells

32 Ground-Penetrating Radar Generally speaking, GPR can locate position and depth of objects within a medium

33 RILEM Tubes (or Karsten Tubes, or Stormdry Gauges) Compare absorption of different types of masonry or before/after treatment Correlation with winddriven rain

34 RILEM Tubes RILEM Test Method II.4: Affix tube to substrate with putty Fill tube with water from top; ensure no leaks through putty Read water level at regular time intervals (e.g. 5, 10, 15, 20, 30, 60 minutes, depending on material and absorption rate) Report results on a graph of water volume absorbed vs. time How many tests? Where? Up to the judgment of the design professional Test standard describes how to do the test, but not how to interpret the results

35 Infrared Thermography Shows differences in temperature not the location of water Requires experienced operator (certified thermographer) Very fast, can cover large areas easily Time of day can be important in effectiveness of testing Early morning building surfaces relatively cool Mid-day building surfaces are warmest Useful for diagnosing: Voids in masonry (including ungrouted cells) Changes in construction (window infills, etc.) Wet areas during water testing Rising damp

36 Non-destructive Testing to Locate Internal Conditions Infrared Thermography

37 Infrared Thermography

38 Measuring Moisture in Building Materials Impedance Measurement Temperature/RH Probes Pin-type Resistance Meters

39 Wood Condition Assessment - Shangri La

40 Common Signs of Wood Deterioration Signs of Decay Fruiting bodies Surface depressions Staining Insect Activity Checks and splits Cubical checking Spongy feeling Mycelium mats Rhizomorphs

41 Wood Condition Assessment - Shangri La

42 Wood Condition Assessment - Shangri La Signs of Insect Activity Frass Earthen tubes Tunnels in wood Swarming in spring/fall Shed wings Chewing or knocking sounds

43 Wood Condition Assessment - Shangri La

44 Species Identification: Shangri La

45 Wood Condition Assessment - Shangri La Resistograph

46 Water Testing - Shangri La Determine leak paths to diagnose problems and design repairs

47 Water Testing Spray Rack and Pressure Chamber We simulate rain with a calibrated spray rack We simulate wind using a pressure chamber on interior and sucking the air out

48 Water Testing Calibrated Nozzle Used to isolate leak paths As a quick check during construction

49 III. Current Problems in Existing Building Systems or Where to Look for the Invisible Window leaks Non-drainage EIFS Cement plaster (stucco) Thin brick and thin stone veneer Hardipanel Flooring failures Balcony decks Early 20 th century buildings deteriorating

50 Common Causes of Window Leakage Not Following Manufacturer s Installation Instructions Open head-jamb corner Confidential material protected pursuant to Evidence Code Sections 1115 et. seq.

51 Common Causes of Window Leakage Sill/jamb Corners Sill/jamb corner is not watertight; jamb drains into wall cavity Reason for using sill pan flashing Confidential material protected pursuant to Evidence Code Sections 1115 et. seq.

52 Common Causes of Window Leakage Missing or Torn Heel Bead or Inadequate Sill Height Leads to overtopping of sill

53 Common Causes of Window Leakage Gaskets Shrink Away From Window Corners

54 Common Causes of Window Leakage Discontinuous Gaskets and Sealant at Mulled Windows Mulled windows are often problematic

55 Common Causes of Window Leakage Lack of Flashing or Reverse-lapped Flashing Incomplete integration of Tyvek with window assemblies

56 Common Causes of Window Leakage Improper Perimeter Sealant Joints

57 Non-drainage EIFS Relies on 1/8 thick lamina and perfect sealant joints for waterproofing No secondary flashings to redirect incidental water to exterior

58 Non-drainage EIFS Problems Cracks, especially at re-entrant corners EIFS finish coat wraps into sealant joint (sealant should be bonded to base coat) Open cell backer rod No sealant joints at penetrations

59 Cement Plaster When installed properly, cement plaster works well All plaster cracks and absorbs moisture there must be a complete WRB w/flashings to handle incidental water that penetrates the plaster Flashings at penetrations are critical

60 Cement plaster Window flashing is critical see ASTM E 2112

61 Cement Plaster Tears and holes in the WRB caused by overdriven lath fasteners Water enters through lath fasteners not engaged with studs or other framing (i.e. spinners )

62 Thin Brick Veneer 3/8 to 3/4 thick bricks Three basic installation systems: Embedded in precast concrete panels Adhered to sheet metal or insulation panels Field-applied to exterior cement plaster or concrete walls

63 Thin Brick Veneer Adhesion Failures Detection methods Tapping Prying

64 Thin Brick Veneer Panelized Wall Systems: Brick Adhered to Metal Panels Thin brick glued to aluminum panels Over rigid insulation Nailed to plywood sheathing Bricks falling off aluminum Entire system separating from building

65 Hardiplank Incomplete integration of Tyvek with window assemblies No flashing between Hardiplank and adjacent barrier EIFS or cornice ledger beam

66 Flooring Failures - Vinyl Newer low-voc adhesives less tolerant of moisture in concrete slabs Shorter construction schedules lead to installing flooring before slabs are dry Lightweight concrete

67 Flooring Failures - Stone Use of thinner stones, low-quality stone, mortar bed shrinkage

68 Flooring Failures - Tile Shrinkage of underlying concrete slab

69 Balcony Deck Assemblies Observations Cantilevered Balconies How they fail and why you need saddle flashings Membrane stops short of deck edge no termination

70 Balcony Deck Assemblies Observations Cantilevered Balconies Water runs off deck, remains behind plaster Building Wall (Plaster and WRB removed) Balcony Deck (concrete and membrane removed) Wood Corbel

71 Balcony Deck Assemblies Observations Cantilevered Balconies Sealant joint between plaster and wood, but WRB unsealed Water continues to run behind plaster, runs behind WRB edge

72 Balcony Deck Assemblies Observations Cantilevered Balconies Water accesses and deteriorates OSB sheathing Water bypasses WRB at edges Unsealed WRB at bottom and side of wood corbel

73 Ageing of Early 20 th Century Buildings Now being rehabilitated in urban areas Steel windows Concrete or masonry cladding

74 IV: Current Problems in the Building Process Why are there so many failures? New products being used without track record or testing Bidding with incomplete construction documents usually schedule driven Low-bid contractors Inadequate construction observation Poor decisions during construction due to schedule or budget

75 Thank you