The Best Flashings To Use On Your New Asphalt Shingle Roof

Residential Roofing

March 27, 2015

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This is a more detailed look at the flashings used in your roof installation. For more information about the rest of the roof, check out this guide on the best roofing materials for your home.

Flashings are a key component of your roof. Not only must you make sure all of the flashings below are installed correctly on your roof, but you also must make sure they are the right quality (and hopefully painted to make your home look good).

The word flashings is a big word, as it technically is used to describe any metal used on your roof. This includes:

  • pipe flashings
  • valley metal
  • drip metal
  • step flashings
  • apron flashing
  • counter-flashing

Flashings are by far the most vulnerable points on your roof since they are covering holes in the roof or joints where the roofing meets something else. This is the most critical part of the roof for your roofers to install right. Most of the leaks we encounter on older roofs are due to flashings that are deteriorated or installed improperly.

Because a roof is supposed to last a minimum of 25-30 years, we highly recommend that all flashings be replaced when you get your home reroofed. Even if all these flashings already exist, they are often filled with holes and are beginning to break down. The only way to ensure your flashings don’t leak in the future is to replace all of them.

Pipe Flashings

These seal around the pipes that stick up through your roof – usually a bathroom vent or Radon vent of sorts. These flashings are critical to a roof’s performance since it is literally covering a hole in your roof. If this pipe flashing fails because of a material or installation defect, water can go straight through your roof into your attic.

The classic type of flashing to use on these are a stainless steel base combined with a black rubber ring that seals around the pipe itself. The only problem with these are that the rubber gets baked in the sun and frozen in the cold. Over time this rubber becomes brittle and will crack. What we recommend is an all-metal flashing that wraps around the hole pipe. Not only will these flashings last forever (no rubber to wear out), but you can also paint them to match the roof and they look great.

Valley Metal

A valley in your roof is anywhere that 2 horizontal planes meet each other, usually at a right angle. This creates a seam between the sheathing where you have to blend two sides together. This is an inherent weak spot in a roof. Since plywood is flat, there will be a sharp corner in the valley, and when you lay felt and shingles over the top it can create an air pocket between the plywood and shingle. If anything is put in the valley (like someone’s foot, a snow shovel, etc) it can break through the shingle and leave a huge hole leading directly into your home.

Since all the water on a roof will run to the valley, this can end in huge problems on the inside of a home. This is why we highly recommend installing valley metal in the valleys. There are two different ways to do it, either a concealed valley metal (works well with the lighter weight shingles), or an exposed valley metal that should be painted to match the roof. Exposed valley metal is necessary when using some of the heavier-weight shingles that you can’t bend through the valleys.

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 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.

Call Us Today For More Information

If you need a quote on roof flashing, call the experts at New Heights today. We serve Spokane, Post Falls, and the surrounding communities.

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