Changes

The roof membrane installed on the SBR is a polymethyl methacrylate (PMMA) membrane, which was liquid-applied and rolled on like paint. By using a liquid-applied membrane, the roof surface has no seams that could lend themselves to leaks on the roof. The SBR has four (4) roof drains and two (2) overflow pipes that direct rainwater to the basement cistern. The roof surface also has two (2) redundant overflow mechanisms called scuppers that can direct rainwater to the foot of the building in the extremely unlikely event that both overflow pipes fail. The SBR is not expected to overflow for over 100 years…

The roof membrane installed on the SBR is a polymethyl methacrylate (PMMA) membrane, which was liquid-applied and rolled on like paint. By using a liquid-applied membrane, the roof surface has no seams that could lend themselves to leaks on the roof. The SBR has four (4) roof drains and two (2) overflow pipes that direct rainwater to the basement cistern. The roof surface also has two (2) redundant overflow mechanisms called scuppers that can direct rainwater to the foot of the building in the extremely unlikely event that both overflow pipes fail. The SBR is not expected to overflow for over 100 years…

==Station 2 – Modulating Control Valves==

=='''Station 2 – Modulating Control Valves'''==

The key mechanisms for the SBR’s ability to hold water are the modulating control valves installed on the third floor. Whereas typical flat roof buildings allow rainwater to passively drain from their roofs without rainwater retention, the SBR roof drains are configured with valves that stop drainage from occurring. These valves allow water to pond on the roof up to a safe maximum depth, determined by the height of the overflow pipes, which is an average of 130 mm in the case of the SBR. Water that is held back by these valves is passed through the SBR’s first CSA-compliant treatment system via a suction line that is installed immediately upstream of the east modulating control valve.

The key mechanisms for the SBR’s ability to hold water are the modulating control valves installed on the third floor. Whereas typical flat roof buildings allow rainwater to passively drain from their roofs without rainwater retention, the SBR roof drains are configured with valves that stop drainage from occurring. These valves allow water to pond on the roof up to a safe maximum depth, determined by the height of the overflow pipes, which is an average of 130 mm in the case of the SBR. Water that is held back by these valves is passed through the SBR’s first CSA-compliant treatment system via a suction line that is installed immediately upstream of the east modulating control valve.