What is flashing?
Let me use it in a sentence. “We had to remove the siding so we could flash the windows” “That window is definitely going to leak, it isn't flashed” “Can you run to the store and pick me up some flashing tape”.
In the contracting world, the word flashing has become both a noun and verb. You can buy flashings at the lumber yard and you can “flash” your windows. Basically, the term flashing describes a system of overlapping materials that diverts water and prevents your windows and doors from leaking. Well, they will still leak. But, the flashing diverts the water safely away from those doors and windows because of the way the materials are shingled or lapped.
Flashing has been around for a long time. Back in the day, flashings were typically made of copper and would flash in the sun, hence the name.
Nowadays, most flashings are made of aluminum or stainless steel. There are also flexible flashing tapes now that use adhesives to seal windows and doors.
Why should you care?
As a homeowner, it's important that you know what flashings are for several reasons.
First, if you are looking to DIY your new doors and windows, you should know what flashing is so that you can do it!
Second, If you are a homeowner looking to hire a contractor, it's also very important that you know what flashing is. You want to make sure that your contractor is doing it! There's a saying- if you want to save some cash, flash!
Flashing is the best way to protect your investment in new doors and windows. The costs of windows and doors only continue to increase over time as does the cost of the labor to install them. You want your new windows to last for as long as possible, so make sure they are flashed!
If you are hiring a contractor, go ahead and ask them, how do you plan to flash the windows? They should be able to give you a response. There is nothing wrong with asking this question. If they get defensive they might not be the right contractor for you.
Is caulking flashing?
No, not really. Caulking is a sealant. It's kind of like the first line of defense to protect your home from bulk water infiltration. The problem with caulking is that it eventually fails. Water is very persistent and will find any little bug holes or separation to penetrate. Caulking doesn't do anything to divert water away, so it isn't flashing.
Caulking and flashing work together to create a system that protects your windows and doors. Immediately after install, the caulking seals your windows and when it rains no water enters. However, 5 years later the sun has beaten down on that caulking and made it hard, the siding has shrunk and a crack appears in the caulking. Now water is free to start leaking into your house to rot away the bones of your home. However, once it makes its way behind the siding, it finds that the opening has been flashed! It tries to leak into the framing but it has nowhere to go, it is diverted down and out of the window sill and continues on harmlessly behind the siding where it finally exits.
Different Types of Flashing
Flashings come in many different shapes and materials, each one designed for a specific purpose. To see a few different kinds of flashings, click here. The type of flashing used also depends on the site conditions. In the photo above, I am installing a copper flashing. I chose copper for this situation because aluminum is known to degrade when installed in direct contact with masonry.
A word about replacement windows
If you are having replacement windows installed, they won't be flashed during install. That is one thing to consider when opting for replacement windows. If you would like to read more about the pros and cons of replacement windows, you can do so here.
