Although we are a commercial roofing contractor, we often find ourselves helping solve leaks that don’t involve the roof. After all, about 30% of all leaks that come into a building are not the roof. Rather than telling the owner it’s not the roof and leaving, Weather Shield trains all of its technicians on the assembly of most building components. Here is just one example from last week.
Weather shield was asked to repair a roof leak a commercial building in the Grand Rapids area. After reviewing the history of the leak, it became immediately apparent that the leak was not coming from the roofing membrane itself. The leak only occurred during long driving rains. It would not leak in a rain without wind, or during a heavy snow-melt. This is typical of a wall leak, as a roof leak in the membrane itself will almost always show up each time one of these weather events occurs.
After reviewing the building plans, we decided to cut into the wall, just above the termination to see if it was installed properly. After taking a few blocks out, we found the problem.
The block wall had almost everything right. The weep holes were designed properly, the insulation backer was in place, and the vapor barrier was intact. The only problem was location of the vapor barrier just behind the block. Rather than turning the vapor barrier up so the moisture that got behind the block shed down over the roof, there was a trough. The water from driving rain soak through the walls which then would fill up the trough and run to the end where it dumped into the building.
The solution to the problem is straight-forward but time-consuming. A mason needed to remove the bottom course of block down the entire wall and slope the vapor barrier so the water would shed out onto the roof.
All in all, Weather Shield was able to find the problem and create a solution for a roof leak that has plagued the owner since the building was built.