Stantec Consulting Limited 40 Highfield Park Drive, Suite 102 Dartmouth NS B3A 0A3 Tel: (902) 468-7777 Fax: (902) 468-9009
June 12, 2012 File: 121411939.200.300
Chignecto-Central Regional School Board 60 Lorne Street Truro, NS B2N 3K3 Attention: Ms. Jackie Fahey Email: [email protected]
Dear Ms. Fahey:
Reference: Building Investigation – Highland Consolidated Middle School, Westville, Nova Scotia
Stantec Consulting Ltd. (Stantec) was retained by the Chignecto-Central Regional School Board (CCRSB) to
conduct an investigation for potential vapour and water pathways in the building envelope at the Highland
Consolidated Middle School (HCMS), located in Westville, Nova Scotia. The assessment was mainly visual,
however some bulk sampling was performed to identify mould. A boroscope was used, where applicable, to
observe areas that were not visually accessible, such as; flutes, roof deck cavities and wall cavities.
Don Hartt and David Ayers of Stantec were on site on May 24, 2012, to conduct the investigation. The visit
was prompted by a recent building assessment that focused on identifying potential pathways for
vapours/odours from roofing materials to migrate into classrooms. Several potential building envelope
deficiencies were observed during this assessment.
LIMITATIONS
The information and observations contained within this report are based on visual assessments of the readily
accessible interior surfaces of the building (i.e., walls, ceilings, floors). Information obtained during the
assessment may not be extrapolated to areas of the building not observed during the assessment.
RESULTS & DISCUSSION
The findings from the visual investigation of the readily accessible interior surfaces of the building are
presented in Table 1.
Table 1 Building Investigation Findings – Highland Consolidated Middle School, May 24, 2012
Location Observations
Room 201 Black tar compound observed in flute area at the exterior wall joint. The tar compound
was on the back side of a foam air-flow stopper and on the wood stud at the parapet
Not all flutes were observed to have a foam air-flow stopper
Northern Stairwell
Black tar compound observed at the end of the flute at the exterior wall
Draft observed in northeastern exterior wall corner at the roof deck
Water staining was observed on wood stud at parapet
Vertical crack continuous to the exterior (outdoors) was observed in southeastern corner of the concrete block wall
Room 203 Water staining observed on wood stud at parapet
June 12, 2012
Ms. Jackie Fahey
Page 2 of 5
Reference: Building Investigation – Highland Consolidated Middle School, Westville, Nova Scotia
Table 1 Building Investigation Findings – Highland Consolidated Middle School, May 24, 2012
Location Observations
Room 204 Exterior drywall wall removed to expose envelope. Apparent mould observed on
plywood wall. Water staining observed on plywood wall
Room 206
Fiberglass insulation is being used to fill gap between structural steel I-beam and metal roof deck along exterior wall. Flashing was used to conceal gap
Portion of drywall wall at window base removed from previous mould abatement exposing wall cavity. Area was re-insulated and sealed with poly. No water-staining noted
Room 208
T-bar suspended ceiling observed in room with fiberglass/vinyl ceiling tiles
Black tar compound observed leaking through holes in flutes and from I-beam along the perimeter
There is a gap between the roof deck and the wood studded support at the parapet which is exposing the thermal layer of the roof membrane
Room 220
Fiberglass insulation is being used to fill gap between structural steel I-beam and metal roof deck along exterior wall. Black tar compound was observed on the wood studs at the parapet
Strong draft observed inside wall cavity behind concrete block wall
Black tar compound observed in flute area at the exterior wall joint. The tar compound was on the back side of a foam air-flow stopper and on the wood stud at the parapet
Not all flutes were observed to have a foam air-flow stopper
Room 218
Rusted steel I-beam observed along perimeter
Building maintenance staff had recently removed a portion of exterior drywall wall to expose the envelope and window framing
Apparent mould (black staining) was observed on the window header, window base and plywood wall.
Bulk samples were taken from would for mould analysis (MBS#1 and MBS#2)
A tape-lift sample was taken from the plywood wall for mould analysis (TMS#1)
Drywall removed from the wall was placed by building maintenance staff in clear garbage bags. A bulk sample from apparent mould on the drywall paper backing was taken for mould analysis (MBS#3)
The window header was observed to be water soaked and rotted
Apparent mould and water staining was observed to be impacting building materials at the floor level and possibly into room spaces below
Room 216
Building maintenance staff had recently removed a portion of exterior drywall wall to expose the envelope and window framing
Apparent mould (black staining) was observed on the window header and plywood wall.
A strong draft was observed in the wall cavity at the roof deck
A gap in the envelope to the exterior of the building was observed at the concrete block/sheet metal siding
Deficiencies in the roof system were evident by the presence of water stains on wood at the parapet in
various locations of the HCMS. This information together with drafts noted at the roof deck/wall joint provide
evidence that pathways for vapour and water to enter the building envelope exist.
During the building investigation, apparent mould was exposed within the wall cavity of Room 218. The
drywall had been removed by building maintenance staff prior to Stantec’s site visit. The mould impacted area
consisted of the interior surfaces of the exterior wood framed wall that supported corrugated sheet metal
siding, including window frames. The deficiencies with regard to the exterior envelope that led to water
intrusion in Room 218 were observed in other areas of the building where the sheet metal siding was
installed.
June 12, 2012
Ms. Jackie Fahey
Page 3 of 5
Reference: Building Investigation – Highland Consolidated Middle School, Westville, Nova Scotia
Bulk samples for mould were taken at the HCMS during the investigation. The results of the bulk sample
testing for mould are summarized in Table 2.
Table 2 Mould Bulk & Tape-lift Sample Test Results – Highland Consolidated Middle School, May 24, 2012
Sample Number
Location Species Identified Fungal Growth
MBS#1 Upper floor, Room 218 Cladosporium sp. colonies Active mould growth
MBS#2 Upper floor, Room 218 Cladosporium sp. colonies Active mould growth
MBS#3 Upper floor, Room 218 Stachybotrys sp. colonies Aspergillus/Penicillium-like spores (heavy)
Active mould growth
TMS#1 Upper floor, Room 218 Cladosporium sp. colonies Active mould growth 1 Aspergillus/Penicillium-like spores may include those of Acremonium, Paecilomyces and Trichoderma
Bulk samples were submitted to Mycotaxon Consulting Limited, located in Halifax, Nova Scotia. Mycotaxon
produces data that is of sufficient quality for Canada Mortgage and Housing Corporation (CMHC), Health
Canada and Public Works and Government Services (PWGSC) for the analysis of mould and biological
contaminants. Mycotaxon Consulting Limited is a participant in the American Industrial Hygiene Association’s
Environmental Microbiology Proficiency Analytical Testing (EMPAT) programs.
CONCLUSIONS
Based on the results of the building investigation conducted on May 24, 2012, Stantec makes the following
conclusions regarding the potential pathways for air/water ingress which allow migration of vapors and
promoted mould growth and dispersal issues:
Potential Pathways
Potential pathways for vapour and water intrusion in the building envelope were identified during the
investigation. These pathways provide opportunity for vapour and water to migrate into the building. The
indicators of pathways observed in the investigation include:
Black tar compound, likely from the recent roof replacement, were observed to have seeped into
ceiling/wall spaces around the perimeter of the roof deck in the upper floor;
Multiple air-flow foam stoppers were missing from flutes at either end of building where wall meets roof
deck;
Black tar compound, likely from the recent roof replacement, were observed to have seeped into ceiling
spaces through holes in the metal roof deck flutes in the upper floor;
Water staining was observed on wood studs in the parapet along the perimeter of the upper floor;
Air drafts were observed within wall cavities around the roof deck/wall joint in several rooms;
Cracks in concrete block walls were noted in the northern stairwell;
Gaps/spaces were observed between the exterior brick façade and metal sheet siding; and,
Deficiencies were observed in the parapet cladding details.
June 12, 2012
Ms. Jackie Fahey
Page 4 of 5
Reference: Building Investigation – Highland Consolidated Middle School, Westville, Nova Scotia
Mould
Prevention of wet conditions in indoor environments and remediation of any mould contamination in
buildings or affected materials/structures is the current emphasis. The growth of mould in indoor
environments is typically due to a moisture problem relating to water ingress through the building
envelope.
Active mould growth (visible as black staining) impacting plywood and wood studs was identified in Room
218. Sources of mould growth typically were related to building envelope deficiencies, such as:
gaps observed between the exterior sheet metal siding and brick façade;
poor condition of the window caulking;
improperly installed sheet metal siding; and
deficiencies around window cladding identified during a previous site visit.
Apparent mould growth was observed to be impacting similar building materials in Room 216 and 204.
Water staining found along the exterior wall in Room 218 did not appear to be pooling at the floor studs,
but noted to follow the plywood wall either into the floor space or room that lies directly below.
Water stained wood studs observed in the parapet in several areas of the HCMS were water-stained. A
likely source of this water staining is the previous roof which was reported to have numerous leaks.
ACTION POINTS
As a result of the assessment, particularly the identification of apparent mould within the wall construction and
consistent with best practices in industry, Stantec offers the following action points for consideration:
Mould may be impacting building materials on both levels and in various areas of HCMS. Given the
unknown extent of impact, a site-specific health and safety plan (HSP) should be developed and
implemented to protect workers and other staff entering the subject building to perform maintenance
duties.
Suspend all activities that would disturb building materials that are potentially impacted by mould (i.e.,
drywall, wood, fiberglass insulation) until the mould remediation objectives are developed in concert with
the HSP.
Verify that poly sheeting and duct tape continues to provide an adequate seal for exposed cavities and
areas where the drywall was removed.
Seal off rooms where drywall has been removed and restrict entry to the subject areas by posting caution
signs on the door.
Personnel entering restricted areas should be equipped with proper personal protective equipment in
accordance with the requirements specified in the HSP.
Recommendations provided in the document titled “Mould Guidelines for the Canadian Construction
Industry” issued in 2004 should be followed for any work disturbing the suspected mould-impacted areas.
A meeting with CCRSB and Stantec should be held at the client’s earliest convenience to discuss these
action points and to develop elements for further assessment of the building according to priorities for
remediation going forward. This assessment would lead to a comprehensive plan for the remediation of
the building.
June 12, 2012
Ms. Jackie Fahey
Page 5 of 5
Reference: Building Investigation – Highland Consolidated Middle School, Westville, Nova Scotia
CLOSURE
This report is prepared for the sole benefit of the Chignecto-Central Regional School Board. The report may
not be relied upon by any other person or entity without the express written consent of Stantec Consulting
Ltd. and the Chignecto-Central Regional School Board.
Any uses which a third party makes of this report, or any reliance on decisions made based on it, are the
responsibility of such third parties. Stantec Consulting Ltd. accepts no responsibility for damages, if any,
suffered by any third party as a result of decisions made or actions based on this report.
The information and conclusions contained in this report are based upon work undertaken by trained
professional and technical staff in accordance with generally accepted engineering and scientific practices at
the time the work was performed. The conclusions presented herein represent the best technical judgment of
Stantec Consulting Ltd. based on the information obtained from the specific sampling locations.
The conclusions presented represent the best judgment of the assessor based on the data obtained from the
work. The conclusions are based on the site conditions encountered by Stantec at the time the work was
performed at the specific testing and/or sampling locations, and can only be extrapolated to an undefined
limited area around these locations. Due to the nature of the investigation and the limited data available,
Stantec cannot warrant against any undiscovered liabilities.
If any conditions become apparent that differ significantly from our understanding of conditions as presented
in this report, we request that this information be brought to our attention so that we may re-assess the
conclusions presented herein.
Sincerely,
STANTEC CONSULTING LTD.
Don Hartt, B.Sc., EPt Environmental Technician Tel: (902) 468-7777 [email protected]
Pamela Sears, MHSc, BFA, CIH Industrial Hygienist Tel: (902) 468-0415
Attachment – Laboratory Report & Selected Site Photos
v:\1214\active\1214xxxxx\121411939 chignecto school board iaq\task 200.300 additional investigation\additional investigation_24_may_2012\rev building
investigation_hcms_12_jun_2012.doc
Project No: 121411939.200.300
Photo 1: Room 201. Flute ending at exterior wall with foam stopper. Flashing covering I-beam. Not all flutes containing foam stopper.
Photo 2: Room 201. Flute ending at exterior wall with foam stopper. Flashing covering I-beam. Tar compound observed on back of foam stopper.
Project No: 121411939.200.300
Photo 3: Room 201. Flute ending at exterior wall supported by I-beam. Tar compound observed on wood butted up against flute at parapet.
Photo 4: North stairwell plenum exterior wall. Water staining observed on wood at parapet.
Project No: 121411939.200.300
Photo 5: Room 208. Showing end of parallel chord roof truss and metal roof deck at parapet. Water stained wood observed along with tar compound.
Photo 6: Room 208. Showing metal roof deck meeting parapet. Water staining on wood and steel I-beam observed. Above wood roof thermal membrane is visible.
Project No: 121411939.200.300
Photo 7: North stairwell exterior wall. Large cracks observed in corners. Ceiling tiles with water stains observed.
Photo 8: Room 220. Exterior wall showing wall roof joint. Fiberglass insulation sealing cavity at parapet between roof deck and steel I-beam support.
Project No: 121411939.200.300
Photo 9: Room 208. Tar compound dripping from holes in metal roof deck.
Photo 10: Room 218. Showing wood rot and apparent mould at window header and on exterior plywood wall. Also observed rusted I-beam.
Project No: 121411939.200.300
Photo 11: Room 218. Showing wood rot and apparent mould at window header and on exterior plywood wall. Also observed rusted I-beam.
Photo 12: Room 218. Showing apparent mould on exterior plywood wall at exterior wall/floor joint. No pooling at base indicating moisture is seeping below floor.
Project No: 121411939.200.300
Photo 13: Room 218. Showing wood rot and apparent mould at window header and on exterior plywood wall. Also observed rusted I-beam.
Photo 14: Room 218. Showing apparent mould at window base and on exterior plywood wall.
Project No: 121411939.200.300
Photo 15: Room 216. Showing apparent mould on window header and exterior plywood wall.
Photo 16: Room 216. Showing apparent mould on window header and exterior plywood wall. Strong draft coming from concrete block cavity at parapet.
Project No: 121411939.200.300
Photo 17: Showing gap in envelope between concrete block/brick façade and sheet metal siding with wood frame.
Photo 18: Room 216. Showing building materials affected by water damage/intrusion around window base.
Project No: 121411939.200.300
Photo 19: Room 216. Showing building materials affected by water damage/intrusion around window base.
Photo 20: Room 204. Showing apparent mould on exterior plywood wall.
Project No: 121411939.200.300
Photo 21: Room 204. Showing apparent mould on exterior plywood wall.
Photo 22: Room 214. Showing window base that has been abated for mould and re-insulated by the CRSB.
Project No: 121411939.200.300
Photo 23: Room 218. Water impacted drywall removed from exterior wall with apparent mould. Wrapped in light gauge plastic bag.
Photo 24: Photo taken from outside window in Room 218 showing detailing around roof curb flashing/parapet.
MYCOTAXON CONSULTING LTD. 3 Rockwood Avenue Halifax, Nova Scotia Canada B3N 1X4 Phone: 902-475-1456 Fax: 902-475-1982 Mr. Don Hartt Stantec Consulting Ltd. Suite 102 40 Highfield Park Dr. Dartmouth, N.S. B3A 0A5
May 28, 2012 Dear Mr. Hartt: Herewith are the results of the microscopic examination of the bulk and tape samples from your project 121411939 Task 200.300, which were received by this laboratory on May 25, 2012. SAMPLE GENERA MBS 1 active growth Cladosporium sp. colonies MBS 2 active growth Cladosporium sp. colonies MBS 3 active growth Stachybotrys sp. colonies heavy Aspergillus/Penicillium-like spores TMS 1 active growth Cladosporium sp. colonies Note: 1. Aspergillus/Penicillium-like spores may include those of Acremonium, Paecilomyces, and Trichoderma I hope this is helpful. If you have any questions concerning this report, please do not hesitate to contact me. Sincerely yours, Mycotaxon Consulting Ltd. Per: Thomas G. Rand, Ph.D. Mycology