Membrane Project

Weather: 21°C, sun and clouds
Workers onsite: Unknown

Work done today:

I’m not sure!

I heard what sounded like work being done on a patio, but I could not see any workers onsite. In mid-afternoon a purple pickup was parked inside the fencing of the emergency repair area and a man was walking across the site, possibly inspecting it.

Weather: 14°C, cloudy with some sun
Workers onsite: At least 1

Work done today:

• No work done today. One person was observed at the C can working on some equipment.
• NOTE: Work is not always done on Saturdays.

Weather: 15°C, showers and clouds
Workers onsite: At least 3

Work done today:

• Work began on the removal of the sidewalk section at the east end of the emergency repair area.
• Work was done to remove membrane on the patio closest to the 244 building main entrance.

The work on the sidewalk is to allow the new membrane to go underneath, creating a proper seal. This was not done in the original design.

Despite working most of the day (and past the 6 p.m. cut-off), the small electric jackhammer used didn’t allow the workers to get much done, as seen below.

Work was also done to remove membrane from the below patio. For some reason, workers elected to use hand scrapers to manually pull the membrane off, rather than the more efficient machines on hand.

Weather: 16°C, clouds and scattered showers
Workers onsite: none

No work onsite today.

Weather: 18°C, showers and clouds
Workers onsite: At least 3

Work done today:

• More grinding of the concrete slab in front of the 244 building, starting around 7:45 a.m.

Several residents reported water leaking into the underground parking. I investigated, as did the Council President. Our findings are below.

First, the water:

This area of the parkade corresponds directly with the exposed concrete slab above in front of the 244 building. There are three drains in the area:

• One drain that was embedded in the gravel near the building
• One drain that was embedded in the soil/garden patch near the fire exit
• One drain that was embedded under the planter

All three drains were completely clogged with dirt.

When the membrane was stripped from the concrete slab in the past few days, the watertight seal around each drain was opened up. Before the membrane was removed, most water would not have gone down these drains, due to them being plugged with dirt, and instead would have flowed elsewhere–which is why water often pooled around the 244 building entrance.

With the watertight seal/membrane removed, water is now free to pour down the outside of the drain piping, in the gap between the pipe and the concrete, through the part that the membrane normally cover. Again, because the drains were plugged, the water had nowhere else to go.

This lead to a lot of water coming into the parkade today when rain showers passed through the area.

It’s hard to see in the shot below, but there is water actively dripping out from around the drain pipe.

The main culprit was the drain that had been buried under the planter:

Because it was plugged with dirt and gravel, it quickly filled up, then water started pouring through where the membrane would have stopped it.

After work with a pressure washer and digging out gravel by hand, the drain was eventually cleared:

Below, the gravel that was removed, plus some of the dirt that had come back up as the pipe was cleared:

A second drain was also cleared. The one nearest to the fire exit did not appear to be leaking, likely due to its location and was left as is.

With the two drains cleared, further showers should see most of the water going down the drains as intended, though some will still leak through the edges until the membrane is replaced.

Below is a drain cover. This normally keeps gravel out, so why was gravel found in the two drains that were cleared?

There is no way to know 100% for certain, but the likeliest answer is drain covers were removed to prepare the concrete slab for work, then when the gravel was moved out of the area, some of it spilled into the exposed drains. All gravel was found on top of the dirt.

There are a few issues here:

• Apparently no one checked to see what the potential impact would be of these drains leaking once the membrane was removed. This is important because in this case, the water leaked onto an area of the underground parking where no vehicles were parked, but this is unlikely to be the case for every drain in the parking lot and central courtyard area.
• If the water had fallen onto a vehicle, it could have potentially caused damage, as there may be material mixed in with the dirt/gravel that could be corrosive or otherwise harmful to automotive paint.

For now, water leaks should be much less severe. The forecast is calling for intermittent showers over the next three days, so we’ll be monitoring to see how well the drains manage now that two have been opened up.