BUILDING ENVELOPE ANALYSIS 341 CHURCH STREET TORONTO ON M5B 1Z3
Conducted by: Kerone Folkes Date : April 13, 2007
This report outlines the analysis carried out on the west faรงade of the Monetary Times Building located at 341 Church Street. It evaluates and summarizes the type of failure(s) identified and the suggested method(s) used to address this problems found.
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Executive Summary This analysis includes conducting an investigation on the Monetary Times building located at 341 Church Street, Toronto, Ontario, whose faรงade is currently undergoing envelope failure. The existing defect being investigated predominantly exists on its west faรงade facing Church Street but has slowly expanding to include its North faรงade. The nature of the defect is represented in three main forms including: granular deposits, shear cracks and efflorescence on the concrete faรงade. If remedial action is not taken soon these defects could prove debilitating to the overall building envelope and some structure and will have to undergo extensive and expensive repairs.
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Introduction This report documents the investigation carried out on the faรงade/ envelope failure of the Monetary Times building located at 341 Church Street-Toronto, Ontario. This building has been a part of the Ryerson University School Campus for over 40 years and has undergone various types of renovation. The defect being investigated predominantly exists on the north and west faรงades of the building, facing Church and Gerard Streets respectively. If not addressed soon, this defect could cause a valuable landmark to either be demolished or undergo repairs.
Description of the Building - Site Plan
The Monetary Times building is a four storey building which is orientated North to south with entrances at the east and west facades. It was acquired in 1966, by Ryerson University and today houses Civil Engineering faculty. - Floor Plans Area of Interest
Concrete Lab Area of Interest
First Floor Plan Page 1
Area of Interest
Second Floor Plan
Area of Interest
Third Floor Plan
Area of Interest
Fourth Floor Plan Page 2
Visual Record of Findings
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Location and Description of the performance defect The performance defect appears to be a facade defect that has gradually progressed to become a fully developed envelope failure. Major deterioration is noticed predominantly on the west side of the building and based on the initial visual analysis of the faรงade, cracks are revealed where upon further testing (manually pushing on it) reveals that the fracture was not a surface fracture. Two additional visual defects were seen which were a shear chunks and granular deposits. A thorough visual inspection was conducted of the buildings exterior and it appeared that the concrete facades were the ones undergoing and or experiencing failure in more than one spot.
Fig. Evidence of failure (Granules, Shear chunk, extensive cracking & waterlogged facade)
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The possible causes of the identified defect are varied and appear to be a combination of weathering and time along with lack of proper maintenance. Other contributing factors related to the defect can include any of the factors listed below. a. The granular deposit could be a result of material deterioration b. The Shear defect could have occurred from the weight of the upper three floors being too much for the faรงade around the window mullion at that point. (compression loading) c. The seal could be damaged, missing or deteriorated around the window mullion. d. The wall may have suffered an impact damage that is now manifesting itself e. Existing latent defects (Human error, product mixing etc.) f. Material performance against adverse weather conditions g. Impacts from occupants and loads, water leakage, incorrect specifications and lack of design clarity, details, and layout. h. Designing with the codes of that particular areas To confirm if the defects extended deeper than the exterior fracture, I was able to conduct an additional visual inspection of the interior room that was located at the worst area of the defect. This inspection revealed signs that the defect had indeed expanded to the interior rooms of the building. The immediate room investigated was the Concrete Laboratory. Here the starts of water penetration were clearly visibly including discoloration on the windows indicating that these windows have lost their insulative properties over the years.
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Fig. Evidence of failure (Water penetration and spots on interior of building along with window discolorations)
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Tests Conducted to determine the causes of the Defect There are a few ways in which a Building performance defect can be detected, the most obvious one beginning a visual analysis of where the defect is starting to manifest itself. By performing a visual analysis one can find out the extent of the cracking / defect across the face of a faรงade the types of side effects it produces (i.e. water marks, salt deposits - efflorescence) Steps taken to initiate investigation of this performance defect can include gathering information with the following methods: 1. Conducting a dilapidation Survey of building and occupants 2. Statistical study (Historical data of building, site, Functional changes, etc.) 3. Analysis (Olfactory/Visual/Touch) 4. Follow-up interview 5. Infrared thermographs equipment that give readings based on the amount of moisture that is present within the sample 6. Structural Analysis (Building materials and practice at the time of construction)
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Mitigation / Remedial Measures Considered Defect: Combination of Cracking/ Shear failure and degeneration Actual Reason Assumed: Structural Degeneration (Building has exceeded it expected Life cycle) Age of Building: 41yrs of use under Ryerson University Location of Defect: Majority located on the West wall with developing defects on the north wall Use of room enclosed: Civil Engineering Concrete testing laboratory Steps towards Mitigation 1. An extensive visual survey of exterior faรงade and interior walls will be performed (note pictures on pages above) 2. For the exterior wall the following test will be performed to determine it the defect is more than a surface one. a. The depth and lengths of the cracks will be measured and documented b. The type of fissure will be noted (shear, diagonal, horizontal or vertical) c. The wall will be physically pushed on to denote how much movement of the faรงade takes place and to also observe if any additional debris falls from the affected area. d. The wall will be then tested with a mallet to see if any of the faรงade breaks away or crumbles. 3. The pieces that were separated by shear will be measured and their location documented on a drawing of the elevation of the building. 4. The various types of cracks will have their locations and directions recorded onto the drawings. 5. If present all wet spots will be tested for water saturation levels and if visible, shape and direction of water spread(s). Page 8
6. Will try to secure an unobtrusive sample for further testing. (Material deterioration) 7. All evidence will be photo documented. 8. A similar visual test will be conducted within the interior of the building with an additional focus placed on the following: a. Smelling for signs of mold and mildew b. Checking sealants and window panes for fissures and or discoloration indicating failure. c. Looking for interior water spots and or early signs of water damage d. Signs of condensation and other related manifestations e. Check ceilings for signs of leakage f. Check along windows for air leakage 9. Obtain structural drawings and /or documentation on building material specifications. 10. Survey key occupants of the building and it facilities to get an idea of other inconsistencies that you might have overlooked. 11. Keep a journal of discoveries.
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Mitigation and Recommendations Having analyzed the gathered data and the existing problem my report would state one or both of the following recommendation to the owner:
Repair 1. Because the faรงade is one of historical significance an attempt can be made to repair the faรงade but I would recommend a deeper investigation be performed to see how extensive the internal damage is as the walls in that section of the building are very thick. (Infrared) 2. It was noted that the test conducted in the concrete laboratory were at times involving extensive vibrations. This is an activity that I would recommend to be stopped. 3. Replace the window and their current seals as they were damaged and no longer perform as designed. 4. Unload the building. It would seem as if the heavy equipment housed within the building is more structural loading than the building was originally designed to carry which would account for the shear failure that was occurring on the lower walls.
Replace 1. Shore up the west faรงade of the building remove the existing damage faรงade and replace it with a similar product based on the specifications written at the time the building was being built. 2. Change the use of the building 3. The building has gone beyond its service life and it is now endangering
its occupants and passersby if it continues to fall apart at its present rate so it therefore it needs to be demolished and rebuilt.
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Conclusion With the faรงade being one of historical significance, I would recommend an attempt to repair it but first a deeper investigation must be performed to observe how extensive the internal damage is to the walls in the sections that exhibit the most damage.
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References Ahmad, A. P. (2004). The Dilapidation Survey Report. Retrieved April 12, 2007, from Understanding Common Building Defects: http://www.hbp.usm.my/conservation/DilapidationSurvey.htm Base, T. (2006, February). Residential Diagnostic Tools. Retrieved April 12, 2007, from Tool Base Technotes: http://www.toolbase.org/PDF/BestPractices/DiagnosticTools.pdf http://www.csinet.org/. (2004). Master Format Specifications 2004 Edition. Retrieved April 12, 2007, from Master Format Specifications: http://www.csinet.org/s_csi/docs/9400/9361.pdf
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