This is part 2 of our guide about The Best Flashings To Use On Your Roof.
Drip Metal
This flashing is installed around the outside edge of your entire roof. A very common type of drip metal to use is the standard ‘G’ metal which measures 1 3/8″ x 1 3/8″ and doesn’t even meet code requirements anymore! That doesn’t stop anyone from installing it though, since inspectors don’t look for it.
To protect your home, drip metal must extend at least 2″ back onto the roof deck. This means the common ‘D’ style drip metal and 2″x2″ ‘G’ metal both work well. We install ‘D’ metal up the side/gable edges (rakes) of your roof and 2″x2″ G metal on the bottom edges (eaves). The reason we install different types of metal is to better protect the fascia board where there is gutters. By using a flashing that extends down 2″ it will prevent water from dripping behind gutters where it won’t dry and rotting out fascia boards.
Another important part of drip metal installation is putting the ice & water shield over top of the eave drip metal (bottom edge) and underneath the rake drip metal (side/gable edge). This way, if you have any ice damming the water that runs off the ice shield will go over the drip metal, rather than running under it into your soffits and possibly your home.
Step Flashings
These are the key to making sure there are no leaks where your roof meets a wall. The reason they are called “step” flashings are because you are supposed to put a new piece on every shingle that you install up a wall, creating “stepped” flashing. Because the common step flashings sold are 14″ long, many contractors will use 1 piece of step flashing for every 2 shingles, which unfortunately does not meet code standards. There should only be 1 per shingle, and to meet code they must be a minimum of 2″ up the wall by 3″ across the deck. We use a standard 4″x4″ which exceeds both of those requirements. A high quality ice shield must always be installed underneath the flashings as a second layer of backup protection.
Apron Flashings
Similar to step flashings, they protect an intersection between the roof and a wall. These go along where a roof meets a wall at the top of a roof surface, and is often called “roof-to-wall.” These come in 10′ sticks and must be a minimum of 2″ up the wall and 3″ on the roof surface. These must be laid in roof cement to prevent water crawling under them. Since they sit on top of the shingle, they have to be surface-fastened, which basically means you’ll see the fastener used to install it. Because of this, we use metal roofing screws that match the color of the flashing so they blend in well and have a rubber grommet that will seal down between the screw head and the flashing.
Counter-Flashing
Counter-flashing is the metal piece that you’ll see on your chimney that extends out from the brick and down over the step and apron flashings. These two flashings work together to keep water from getting into your home in the most vulnerable areas on your home, your chimneys. Often times, counter-flashing is re-used over and over again on older homes, and by the time we get to it it is rusting out and failing. Or it’s just really ugly from being bent back and forth a few times and gooped and covered in tar to stop leaks. We always recommend completely replacing counter flashing to maintain the integrity of the roof for a long period of time.
When possible, we use a solid piece of flashing that extends down the whole chimney. It looks really good plus it prevents water from blowing into seams and running down the chimney.