Roof flashing: the most common leak point

If shingles get all the attention, flashing is the quiet part doing the hard work. It’s also the part that fails most often. Understanding it helps you see why some leaks keep coming back even after the shingles look fine.

What flashing is and where it goes

Flashing is thin metal, usually aluminum or galvanized steel, bent to seal the spots where your roof meets something it can’t shingle over. Shingles handle the flat open areas just fine. The trouble is always at the transitions.

You’ll find flashing around chimneys, along walls where a roof slope butts up against siding, and in the valleys where two slopes come together. It also wraps skylights and seals around vent pipes.

Each of these joints is a seam, and every seam is a chance for water to get in. Flashing is what closes that gap.

Why flashing fails

Metal moves. It expands in the Georgia heat and contracts in the cold, and over years that flexing works fasteners loose and opens small gaps. Old flashing can also rust through or pull away from a wall.

Bad installation is just as common a cause. If flashing was nailed wrong, sealed with caulk instead of proper metalwork, or reused when it should’ve been replaced, it leaks no matter how new the shingles are.

Because flashing sits at the busiest water paths on your roof, even a small failure there lets in more water than a gap out in the open field would. That ties directly into the common causes of roof leaks, where flashing tops the list.

Why a good replacement redoes it

Here’s where corners get cut. Some crews lay new shingles right over old flashing to save time and money. It looks clean on day one, but you’ve just built a new roof around its weakest link.

A careful job replaces the flashing along with the shingles, or at minimum inspects every piece and reworks what’s worn. New chimney and valley flashing done right is what keeps those joints dry for the life of the roof.

So when you compare quotes for a roof repair or a full replacement, ask how the flashing gets handled. If you want a straight answer on the shape yours is in, book a free inspection and we’ll show you what we find.