How Façade Ordinances Affect Your Historic Building

Transcription

1 How Façade Ordinances Affect Your Historic Building Carolyn L. Searls Simpson Gumpertz & Heger 12 May

2 Copyright Materials This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited.

3 Learning Objectives Understand the requirements of different city facade ordinances including San Francisco s. List the steps involved in a successful building enclosure inspection program. List inspection techniques and different technologies. List common indicators of building enclosure degradation.

4 Presentation Outline Reasons for a building enclosure survey City Facade Inspection Ordinances Safety Prepurchase survey Capital project planning Identify maintenance needs Description of an inspection program Inspection techniques and technologies Common indications of facade problems

5 Who s Attending Today (Poll)? Profession Architect Engineer Planner Historian Other Employer Government employee Private consultant Building owner/manager

6 Presentation Outline Reasons for a building enclosure survey City Facade Inspection Ordinances Safety Prepurchase survey Capital project planning Description of an inspection program Inspection techniques and technologies Common indications of facade problems

7 City Ordinances Forces building owners to take responsibility for the condition of the building facade Most city ordinances do not require a comprehensive hands-on survey of all elevations Most cities do not have any requirements for shorter buildings Depending on condition and facade type, the components of the facade can deteriorate more quickly than 5 or 10 years Do not require inspection of roofs or other non-facade components Often represent minimum requirements!

8 Cities with Facade Ordinances in US Boston, MA Chicago, IL Columbus, OH Detroit, MI Milwaukee, WI New York, NY Philadelphia, PA Pittsburgh, PA St. Louis, MO San Francisco, SF (in progress not yet active) Affects over 13,000 buildings in these cities! Typically required at 5 year intervals (SF=10 years) Typically required for buildings over 5-6 stories tall (SF=5 stories) Typically require at least one representative scaffold drop or similar hands-on inspection (=SF) Typically require licensed architect or engineer to perform inspection (=SF)

9 Poll: Does your city have a Facade Ordinance? Yes No

10 San Francisco Proposed Ordinance Under development since 2013 still not finalized Purpose To assure building facades are maintained To improve public safety by reducing falling hazards Clarifies requirements already in Ch. 34 of SF Building Code Side benefit Fewer facades falling in an earthquake The ordinance does not: Require upgrading of facades to meet current seismic or structural standards

11 Why Does San Francisco Need a Façade Ordinance? Facade Hazards Building Owner s responsibility to keep public safe and mitigate potential falling hazards.

12 San Francisco Proposed Ordinance Covered Buildings Buildings Covered by Façade Ordinance Over 5 stories Not wood-framed construction Facades facing publiclyaccessed areas Privately and city-owned Exceptions Buildings with comprehensive façade repairs in the last 10 years Buildings permitted after 1998 start inspections 30 years after construction Schedule Initial inspections phased in over 10 years, based on age of building, starting in 2018 Subsequent inspections every 10 years, or if visible façade distress

13 San Francisco Proposed Ordinance Façade Inspection Scope Similar to ASTM E2770 Standard Practice for Periodic Inspection of Building Facades for Unsafe Conditions Re-inspection at 10 year intervals not 5 No mandatory inspection openings Inspection done by licensed architect or engineer Includes up-close, hands-on inspection (25% of each façade) Report to owner and DBI (City Department of Building Inspection) Maintenance and repair must return building to its permitted condition: vertical and lateral load carrying capacity and general waterproofing

14 Classification and Repair of Façade Condition Façade condition classified as: Unsafe: Imminent hazard to persons and property Requires repair/stabilization: Actions needed to prevent deterioration to an Unsafe condition before the next required inspection Requires ordinary maintenance: Ongoing maintenance, but no immediate or urgent action required Reporting of unsafe conditions: Report to DBI immediately Describe repair or stabilization required Submit plan and schedule of work w/in 72 hours Planning Dept. Preservation staff must review actions on historic resources

15 San Francisco Proposed Ordinance Historic Buildings Inspector must be experienced in historic buildings Inspection methods least intrusive Refer to California State Historic Building Code or best practices Resulting maintenance/repairs to be approved by Preservation Planning Staff Maintenance and repair to be in accordance with The Secretary of the Interior s Standards for the Treatment of Historic Buildings

16 San Francisco Proposed Ordinance For more information or to join the working group: City & County of San Francisco Earthquake Safety Implementation Program, click on Façade Maintenance

17 Presentation Outline Reasons for a building enclosure survey City ordinances Safety Prepurchase survey Capital project planning Description of an inspection program Inspection techniques and technologies Common indications of facade problems

18 Facades - Safety Chicago

19 Facades - Safety

20 Facade Hazards Building Owner s responsibility to keep public safe and mitigate potential falling hazards. Cracked terra cotta + corroding steel lintel = incipient spall

21 Facade Hazards Cracked and hollow sounding plaster was a large incipient spall at main entrance of a assembly building

22 Hazard Mitigation Options What to do if you find a falling hazard 1. Canopy: Erect protection sidewalk canopy Canopy will protect public from falling pieces Canopy can be designed to support scaffolding for the eventual repair 2. Temporary stabilization: pick and clean 3. Permanent repairs 4. Do nothing (not recommended).

23 Protection Examples Canopy: Erected sidewalk canopy after investigation and left in place thru design and construction of facade repairs Sidewalk canopy in place during terra cotta and brick repairs. Repairs from swing stage.

24 Protection Examples Terra cotta repairs done using combination of sidewalk canopy, swing stages and fixed scaffold Temporary stabilization: removed loose stone once during the middle of multi-year repair program, so that sidewalk canopy could be removed from that area until complete repairs done.

26 Prepurchase Survey Identify building enclosure systems through drawing review Exterior survey of facade, roofs, and other exterior components Interior survey Understand construction interior and exterior sample openings if necessary Goals: Identify safety issues Identify immediate needs to maintain building performance and prevent costly rehabilitation projects Identify future maintenance or capital needs

27 Prepurchase Survey Commonly survey done from ground with binoculars and set-back roofs and balconies We obtain better information when we can get close-up to the building

28 Prepurchase Survey Example Cost Spreadsheet 4.3 WALLS AND WINDOWS Quantity Unit Unit Cost Repair Cost Walls Clean entire building exterior by powerwashing Repoint deteriorated mortar joints at brick cladding (assume 10% total brick mortar joints) Repoint deteriorated mortar joints at roof parapet and cast stone joints Install a deck coating such as Kemperol 2K-PUR membrane over the repainted masonry roof parapet at the Main Street and Capitol Street elevations Repair the cracked brick corner of the penthouse at the west side of the roof by removing displaced brick and rebuilding corner Repair the vertical crack at the east corner of the Capitol Street elevation. Remove brick on both sides of corner to expose column. Clean and paint steel. Reinstall brick, including shelf angles, bed joint reinforcement and brick ties. Replace all window lintels at the north, south, and east elevations. Remove brick at lintels, remove exist. lintel, replace w/ new s.s. lintel, install stainless steel flashing, replace brick, install new sealant joint with weeps. 47,000 sf $ 3.00 $ 141,000 12,688 lf $ $ 190, lf $ $ 5, sf $ 25 $ 10,125 1 ea $ 15, $ 15,000 1 ea $ 20, $ 20, ea $ 1, $ 193,200 Repair costs usually projected by year over 10 years

30 Capital Project Planning Similar to pre-purchase, but for an existing Owner Can be a single building or campus Goals: Identify building enclosure condition Identify future maintenance or capital needs List all items and remaining service life and cost for repair or replacement

31 Capital Project Planning Inspection Inspect all roofs, balconies & ledges where water can get in Inspect all projecting elements & balustrades Inspect interiors for water leakage Binocular survey Close-up survey if possible

32 Identify Maintenance Needs Failed joints, plant growth, and cames with failed joints at bandcourses

33 Identify Maintenance Needs Leakage into attic and corroding steel framing Water weeping from joints and efflorescence

34 Preventative Maintenance Limit water infiltration to prevent accelerated deterioration of underlying structure Point failed mortar joints; included water repellant admixture in pointing mix Provide flashing at projecting masonry surfaces

35 Capital Project Planning Example Prioritization High Priority Repairs Moderate Priority Repairs Condition Cracks and spalls at terra cotta lintels w/corroding steel (0 5 years) Localized cracks and previous repairs (not a falling hazard) Repair Inspect and stabilize lintels or erect sidewalk canopy. Remove and replace corroding steel lintels and terra cotta Fill cracks with mortar Low Priority Repairs (5 10 years) Localized sealant failure Remove and replace failed sealant

36 Capital Planning Project Phasing & Budgeting Phase Cost Duration Phasing starts with area with high priority needs life safety or causing further deterioration Complete all work in each area because cost of access is high

38 Poll Have you performed a building inspection? Yes No Have you commissioned a building inspection? Yes No

39 Setting Up a Successful Building Envelope Inspection Program Typical process guided by ASTM E Standard Practice for Periodic Inspection of Building Facades for Unsafe Conditions 1. Document review 2. Preparation of inspection documents 3. Review service history history of leakage, previous repairs, etc. 4. Interior visual inspection 5. Exterior visual inspection a. General inspection b. Detailed inspection c. Nondestructive evaluation d. Destructive evaluation 6. Report of unsafe conditions 7. Report of findings

40 Additional ASTM E2270 Recommendations Recommends both General and Detailed Inspection General inspection (visual) survey from a distance greater than 6 ft Detailed inspection (hands-on) survey from a distance less than 6 ft, non-destructive testing and making openings Recommends inspection once every 5 years Report by a qualified professional ASTM E2270 is for facades, but roof or comprehensive envelope inspection program should follow similar steps

41 ASTM E2270 Continued Recommends inspection level for each type of façade material. Masonry, Concrete, Terracotta, GFRC, Stucco, Barrier EIFS 100% general inspection 25% detailed inspection of each façade type 3 sample openings per façade type Pull tests on adhesive attached components

42 Inspection Reports Report and drawing content/detail are dependent on intent of inspection and Owner s future needs Minimal report or drawings needed to satisfy most ordinances Report typically lists observations and includes recommendations for: Any urgent remedial repair work for unsafe conditions Any areas requiring future repair or stabilization Any additional investigation needs Any future monitoring requirements Report typically include annotated drawings identifying observations/repair locations or further investigation locations

43 Hand Annotated Drawings

44 Electronically Annotated Drawings

45 Electronically Annotated Drawings

46 Presentation Outline Reasons for a building enclosure survey City ordinances Safety Prepurchase survey Capital project planning Identify maintenance needs Description of an inspection program Inspection techniques and technologies Case studies

47 Inspection Methods - Facades Visual Survey From ground and adjacent buildings, typically with binoculars Interior survey for damaged interior finishes and water leakage Technology is rapidly changing and new methods of visual survey are developing Gigapan (high definition photography) Drones Pros: Lowest cost Cons: Areas of deterioration and potential hazards may go un-noticed

48 Exterior Facade Survey

49 Facade Hazards

50 Interior Survey Water Leakage

51 Inspection Methods - Facades Hands-on Survey Requires equipment to access upper levels Extent of survey (i.e. number of drops ) depends on Owner. Most City Facade Ordinances only require one drop per elevation; ASTM requires 25% Pros: Better, more reliable method to identify deterioration and hazards (though dependent extent of survey) Falling hazards can frequently be accessed; smaller hazards can be removed during the survey Cons: More expensive

52 Facade Inspection Determining Access Method Site Traffic Police Details Cordoning Requirements Permits Adjacent Properties Building Geometry Height Cornices Facade Setbacks and Projections

53 Facade Access Methods - Lifts Pros Simple setup; easy to move Can perform repair work Cons Height limitations (typically 150 ft max) Site must have adequate grade-level access for machine

54 Facade Access Methods Swing Stage Pros No height limitations Can perform repair work Cons Requires contractor setup at each drop Cannot easily navigate around projections, atypical facades, etc.

55 Access Methods Industrial Rope Access Pros No height restrictions Quickly remobilize to new drop locations Cons Only limited repair work can be performed Requires special training

56 Hands-On Facade Inspection Document existing conditions Remove small spalls or deteriorated facade Non-Destructive Investigation Crack gauges Hammer sound concrete and masonry Pachometer or GPR to locate steel IR scan for air leakage

57 Hands-On Inspection Document Conditions

58 Hands-On Inspection Identify Deterioration

59 Remove Delaminated Spalls

60 Exterior Window Gaskets and Sealant Joints

61 Measuring Cracks and Crack Movement

62 Hammer Sounding

63 Pachometer or GPR to Locate Steel

64 IR Scan for Thermal Anomalies

65 Destructive Testing Take samples of concrete, masonry, or other components for further lab testing Sample openings to observe hidden conditions Sampling or openings typically require contractor assistance for removal and repairs Or small holes or openings to review hidden conditions with boroscope

66 Samples for Material Testing Concrete Depth of carbonation Total chloride content Petrography Masonry Freeze/thaw durability Mortar analysis Petrography Hazardous Material Testing Coating or Sealant Identification

67 Exploratory Openings - Rust Staining Rust stains help locate deteriorated anchors or framing hidden in wall system

68 Exploratory Openings Masonry Distress

69 Exploratory Openings - Borescope

70 Presentation Outline Reasons for a building enclosure survey City Facade Inspection Ordinances Safety Prepurchase survey Capital project planning Identify maintenance needs Description of an inspection program Inspection techniques and technologies Common signs of facade problems Top 10

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

72 9. Efflorescence and Water Stains Look for white powdery stain; indicates water movement

73 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

74 7. Cracks Look for these normal shrinkage cracks

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

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

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

78 6. Paint Failures Look for blistered, cracked or peeling paint

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

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

81 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) Wood deterioration Steel window corrosion

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

83 1. Pieces Falling Off And we re back to where we started, with facade inspections and the reasons for facade ordinances

84 Thank you. Questions? Carolyn Searls