This article is dedicated to a very specific roof repair. This is a split level house with a second story roof over a single story roof. The exterior of the house body is lap siding. The first story roof in question is back-pitched into a second story wall. During a heavy rain water comes off of the second story roof and is dumped onto the first story roof. The water is then routed into a dead valley that leads straight into the second story wall (poor architectural design). Over many years of this water slamming into the second story wall, it eventually started leaking over the flashing and under the shingles onto the family room ceiling below and ultimately ruining the drywall. What we are going to go over is how to minimize the amount of water in this area and repairing the roof. In this case we know where the problem area is. The problem is where the first story roof meets the second story wall, so this is where we will start. In roofing, shingles start at the bottom overhang of the roof and are laid up the roof to the peak. They are then finished off with a roof cap of some sort. We will begin by reversing this process.
Clean the debris from the area of roof you will be working on.
Remove the roof cap, starting at the wall, back to the length of the first shingle at the peak of the roof.
Remove the shingles from the wall. Start at the peak and work your way down to the eve Remove only what is necessary. In our case, we removed no more than one full shingle (mostly partial shingles) all the way down.
Once the shingles and nails are removed, fill the nail holes with roof sealant.
At this point, we could see that the 5×5 flashing, that goes from the roof to the wall, had been installed incorrectly. We could actually see the top of the flashing was cut (big no no!) below the bottom of the siding allowing any heavy rain a direct route into the house. At this point we decided the best method of repair was going to be to fill in the old 5×5 gap with roof sealant and start over with a new design.
Fill the gap, from the bottom of the siding to the roof deck, with roof sealant. You don’t have to be especially clean here as it will be covered with new 5×5 flashing and 1×4 pressure treated trim.
Install new 5×5 flashing per manufacturers recommendations. Make sure it is sealed well.
Cut and install your new shingles. Make sure the edge that lays on the 5×5 metal has a very thick bead of sealant under it.
Once your shingles are installed, install your top cap and you are done with the shingles.
Cut and install the 1×4, approximately 2 inches off the roof deck, on the wall. Before installing the 1×4 make sure you put a very thick bead of silicone or other sealant behind the 1×4.
Paint the 1×4 and flashing.
After the paint has dried, seal the top of the 1×4 to the siding. Here you will have some nice sized gaps, so make sure you fill them well.
Clean up your mess and we can move on to the next step.
Earlier we talked about minimizing the amount of water that flows onto this roof. There was approximately 400 square feet of roof water being dumped onto the roof below. In order to stop this we needed to reroute the second story water into gutters and down spouts leading the water away from this area. This is probably the most important step. I will create another post on gutter installation. After you have installed gutters and downspout your job is complete and you can now enjoy a nice dry house!