Western Fin inancial Pla lace Cit City of f Cr Cranbrook Co Council il Prese sentatio ion February 25 th , 2019 Presentation by: Building Consulting Services Kevin Wilkins 2018 Repair irs and Repair ir Opti tions movin ing forw rward
• WPF has been experiencing moisture issues for many years. • The existing TPO roof membranes have reached the end of their life cycle and are showing their age. • Over the past few years RJC and IRC have completed reports on the roofing issues. Both of those reports provide a very detailed and valuable review of the roof assemblies, cut test, components, budgets and other related issues. • Our report and opinions are based on our own review and much of the information provided within those reports. BCS did not complete cut tests. • The IRC report uses a numbering system for the different roof areas. We have maintained that same numbering system in our report for consistency between report.
The WFP roof areas are as follows; • 1.1 - Office Patio (Mechanical Fastened - MF) • 1.2 – Rear Entry Roof (MF) • 1.3 – Rear Canopy (?) • 2.1 – Stair Roof (MF) • 2.2 – Change Rooms (Fully Adhered - FA) & Concourse Roof (MF) • 2.3 – Arena Exit (MF) • 2.4 – Arena Exit (MF) • 3.1 – Restaurant Roof (New SBS in 2018) • 3.2 - Pool Roof (FA) • 3.3 – Racket Ball Roof (MF) • 4.1 – Arena Roof (MF) • 5.1 – Elevator Roof (MF) Mechanical fastened roofs are typically used over normal humidity environments, where Fully Adhered membranes are recommended over high humidity environments like Pools and Change Rooms.
• While both the RJC and IRC reports are very detailed, there is limited information as to exactly when and where within the complex the water issues have occurred, as the City could not provide such records. • Through discussion, it seems the roofs generally do not leak throughout the year during normal rain fall, other than at a few select locations, like as seen at the yellow tarp in the Concourse. • It is BCS’s opinion that the majority of the water issue occur in early spring during warming cycles after long Roof leaks extreme cold cycles. year round. • BCS has asked the City to review and document any water issues within the complex through this 2018- 2019 winter to assist in confirming our opinion.
Current Condit itions of f Roof Systems TPO membrane is aged and deteriorated: • Cracks and splits • Reduced flexibility in old TPO membrane due to age (i.e.brittle) • Stretched membrane
Pool Roof • Adhesive failure in the fully adhered roof • Insulation buckled up • Repaired in 2018 Insulation de-bonded and lifted off vapour barrier
Stretching and Deterioration of f Roof f Membranes • Wind uplift forced on Mechanical Fastened TPO creates stretching forces • Air movement within billowing TPO moves vapour around in the assembly
Conditions that cause moisture issues in roof systems : • Air movement under the membrane • Cold outside temperatures create • Wind induced from membrane billowing thermal variances & vapour drive. • Air leakage from interior through • High humidity interiors combined penetrations and at roof with warm temperatures junctions/perimeters
Roofs with a single layer of insulation reduces thermal resistance • Insulation installed in one layer. • Insulation board move around due to window suction loads. • Gaps between joints of insulation boards develop. • Heat transfer through metal fasteners. Improvements with double layered insulation • 2 layers of insulation • Fully adhered, no fasteners • Insulation gaps lapped.
• In review of the original construction drawings, BCS has concerns about the location of the vapour barrier within many of the constructed roof edge assemblies. • Poor vapour barrier construction was confirmed during dis-assembly of the Restaurant roof. • The Parapets should have been designed to include a vapour barrier at the red line, (as seen to the left), at the bottom of the parapet, to close off and prevent vapour from entering the cold parapet. • Within the constructed parapets, when vapour enters and contacts cold surfaces it condenses back to moisture, and if cold enough will freeze. More vapour is then drawn in, contacts the cold surfaces, condenses and continues to freeze and begins building up frost within the parapet Parapet: is the upstand wall located at roof edge. construction.
At WFP… LEFT: Thermal representation of parapet’s internal temperatures. RIGHT: Resulting potential frost zones within the parapet in cold climate. The higher the humidity within the building the greater the amount of frost.
Here are some examples (from other When all this frost melts it buildings) with roof results in many gallons of frost build up within a water running back into the roof assembly due to building. This is not a roof interior vapour loss. leak. Replacing roof membranes does not fix this.
• In consideration of these cold parapet locations and internal frosting, in the image to the right, the thick red line shows the location of the parapets immediately adjacent or above high humidity locations. • BCS assumes the red line locations are the areas of the building where the majority of the water issues occur in warming weather cycles. • The City is in general agreement, and is monitoring it this winter. • Conclusion: Parapet vapour barriers The parapet/wall location along the Restaurant/Arena must be repaired as part of any roofing was repaired during in 2018. repairs or replacement.
Moisture within Assemblies and RISK The GREEN area is the Restaurant roof and was replaced in 2018. The RED areas have moisture above and below and/or within the insulation, are delaminating and require replacement. The YELLOW areas are recommended for repair and only have moisture within the assembly at the top of the insulation at the dew point. The RISK of probably failure is LOW for these roofs. So a proper repair could last 20 plus years.
Repair and replacement options The options reviewed in our report were; • Repairing with cover strips (An option, but not recommending) • Repair with a liquid applied coating (No longer an option, due to manufacturer’s change in warranty as they are no longer providing a Flaking and Peeling warranty.) • Complete removal and replacement with new TPO roofing. • Complete removal and replacement with SBS roofing. • Spray foam application to Arena barrel roof, (an option only for the arena). • We have just added an option of EPDM membrane replacement, with a manufacturer’s warranty and possibly an RCABC warranty, which will be discussed later in this presentation. We are still working with the manufacturer with respect to details.
Carlisle Fleece EPDM Repair • Black EPDM rubber roof • Provides a warmer roof due to solar heat gain • Adds additional insulation, R-2.5 • Lowers the dew point down into the insulation producing better characteristics for drying the roof • 20 year roof membrane warranty, and possibly a RCABC Warranty • Less disruption to building. • RISK: Frosting may occur in the unrepaired parapets over low humidity environments, (LOW RISK).
Intent of Repair Option • Remove existing TPO membrane and let moisture dry from top of TPO for a few hours. • Remove insulation at parapet and install new vapour barrier to seal ends of insulation. • Adhere down new Rapid Lock Cover board. • Install new EPDM membrane. • COST RISK: Must replace any saturated insulation. • COST RISK: If insulation is loose and /or damaged in the fully adhered systems all the insulation & vapour barrier will be required to be replaced for that roof area.
Restaurant Roof Repairs completed in 2018 • The Arena / Restaurant wall was repaired in 2018. • The old TPO roof was removed. • New SBS roof was installed with higher R-value to meet code.. • Poor parapet vapour barrier details were repaired around the perimeter of the Restaurant Roof and Elevator roof. • A substantial leak was discovered and repaired at the Elevator roof that was leaking into the Stair below. • With the Restaurant roof and wall repaired, there have been no further moisture issues/leaks below these areas.
• We placed RED and GREEN dye within the Arena Roof to monitor any moisture within the Arena roof. The GREEN dye washing out as seen in the photo indicates a fair amount of moisture flowing on top of the vapour barrier. At this point in time, we are uncertain whether the moisture is from vapour loss and frost, or if the TPO is leaking. • We are still monitoring and considering further testing. • What this means is….
Arena/Restaurant Moisture moving on top Wall of vapour barrier. Continuous Membrane. ? Unknown Arena Roof Overhang Arena/Restaurant - Existing condition Wall - Repaired in 2018
Arena Soffit Overhang adjacent Elevator Shaft Water staining Leak discovered and repaired in 2018
Recommend
More recommend
