What can I do about the joint between my roof and brick wall leaking?

Question

I have a bay window with its own roof, that connects to a brick wall. The joint between the roof and brick leaks when water is sprayed at or otherwise lands on the brick -- during our last hurricane, gallons of water made it through into the room below.

At first, I thought it was an issue with the roofing company using the preexisting flashing, but they've come back and completely redone the roof and flashing, and the leak remains.

Could something be wrong with the brick, and is there anything I can do about it? Or is this something that can be resolved at the flashing junction? I've tested this area with a hose -- water sprayed onto the flashing itself doesn't cause a leak. Water put on the brick directly above the flashing causes a steady stream of water into the room below.

Answer 1

From what I've seen, the standard approach for flashing where a sloped roof is adjacent to a brick wall is to use step flashing and counter flashing.

The bottom flashing is made as a series of steps that are installed underneath the adjacent shingle, and bent to run vertically up the wall. The next piece partially overlaps the previous one, and ends one step higher on the wall, etc.

The counter flashing is installed over the bottom flashing, and is imbedded into a slot cut into the mortar joints between rows of bricks.

In your picture, it looks like the bottom flashing is just one long piece sitting under the shingles, and the top piece is also one long piece, totally dependent on globs of silicone to keep water out - which it's clearly not doing.

The step approach is routinely used on brick chimneys that penetrate the roof, and there are many articles and videos showing how to do it - search for "step flashing chimney" or "step flashing brick wall", for example. Here is one article that shows much of the process.

Answer 2

To prevent the bricks absorbing water coat the bricks.

To prevent the leaking from above the flashing, remove it and use mortar to make the surface flat, by filling all spaces, then use silicone to seal.