It's rainin' again

With no roof covering, the worker dudes tarped me up and left me for the long weekend. At 11:15 PM on Saturday night, it started to rain. At 11:30, there was a waterfall in my stairwell. Oops. So in the dark and the rain, I climbed up onto the roof, laid out more tarps (note to self: old, rotten cedar shakes are slippery when wet). I also put some plastic up inside to try and direct the water away from the wallboard (that we were planning on keeping) and onto the stairs and the carpet (which we are also planing on keeping). My extra tarping reduced the waterfall to a trickle, but didn't stop it. The rain stopped around midnight, as did the waterfall.

The improvised plastic shield 

Water was leaking in from the inside of the window

The dehumidifier had the carpet dried by the morning, but the damage to the  wallboard under the window was done. It was blistered and bulged and is now soft in spots. My contractor came over on Sunday morning and re-tarped the roof.

The new tarping system

So what happened was that the new roof section had been tarped, but water could still run off the rest of the house and down the valleys, under the tarp to the lip. But there were several gaps in the new roof sheeting, and they had removed to old roof sheeting underneath. So water that made it under the tarp had unimpeded access to the ceiling over my stairwell. It's likely that it then hit a plastic vapour barrier, because the ceiling drywall doesn't show signs of wetness. But the plastic must end at the window, and the water is re-directed there, where it pours out. So the new tarping strategy covers all the roof that drains to that area with tarps, including the sunroom. 

Any reno where the roof is removed is a risk for rain damage so long as there's no roof. When we added the 2nd story to our house in Calgary in 2005, we were roofless for about 3 weeks. Not long after they took it off, it rained (on a Sunday morning at 8 AM) and started leaking into my house. I immediately called my contractor, who showed up within 20 minutes and re-tarped me. That one wrecked a bit of ceiling drywall that we should have replaced, for you could still see it years later. Such are the perils of removing roofs.