Places That Roofs Tend to Leak

Places That Roofs Tend to Leak

Places That Roofs Tend to Leak

Of all the structures that make up your home, your roof is undoubtedly the most important.  The proper functioning of your roof protects your valuable investment, but it also keeps your family safe – and what could be more important than that?  Whether there’s a little water dripping down from your ceiling, or a new pond has been created in your living room, chances are, your going to want to know where that leak is coming from.  Actually, roof leaks tend to occur in specific locations on your roof, and are often caused by various types of weather conditions. Below are some places where roof leaks are likely to happen.


Although the very purpose of flashing is to gaurd against leaks, when they are malfunctioning, they can actually be major targets for water to seep through.

Vent Flashing

plumbing vent

The major element of plumbing vent flashing that makes it prone to leaks is its rubber seal. For some reason, the rubber seems to only be durable for about 10 years. So, it’s important to watch out for cracking rubber around your plumbing pipe. This flashing should shoot up and under the shingles that go up the roof from the center of the plumbing vent. The bottom half of the flashing should be exposed, and actually blanket the entirety of the shingles.


The distinguishing characteristic of b-vent flashing from regular plumbing vent flashing is that it often comes equip with a metal storm collar. This “collar” fits securely around the vertical pipe, but if it’s loosened, a leaking roof can easily occur.

Wall Flashing

head wall

This flashing exists where a roof stops once it reaches a wall.  Head wall flashing must be installed to direct water streaming down the wall, away from the stopping point of the shingles. Head wall may be behind wood siding, or in front of a brick wall. It should extend over the shingles by three inches, at least. If the wall consists of masonry or brick, the flashing ought to bend and extend one inch into a mortar joint.

wall step

While some flashing sits where a roof stops, wall step flashing resides where a roof extends alongside a vertical wall.  As each new row of shingles is put down, a step flashing is installed over the shingle next to the wall. Part of the flashing is laid up on the wall, while the other portion becomes covered by the next row of shingles.  Notice deterioration and rust on this flashing. You should only be able to see a small portion of it sticking out.


vertical slits

Vertical slits between shingles are the first places you should look for corrosion that might be causing a leak.  Specifically in 3 tab asphalt shingles, it is not at all strange for leaks to develop in the top 3 inches of each vertical slit.


These ceramic, color-coated particulates of crushed rock protect the asphalt from the destructive ultraviolet rays of the sun. When they are over exposed to sunlight, the asphalt within the shingle begins to corrode.  However, granule erosion in the vertical slit area” tends to happen when water drips from the shingle above. Since this is a small area it’s difficult for the sun evaporate any moisture. The granules at the top of each slit receive twice as much energy from the dripping water as the granules on either side of the slit. This might not seem like it would do all that much harm, but over long periods of time, roof leaks due to this are not uncommon.

Roof Valleys

If you don’t want a leaking roof to take place in your roof valleys, the best thing you can do is to trim your shingles correctly.  Usually, when you trim a shingle for a valley you end up with a rough point on the end of the shingle. If a second cut is not done to make this point straight, water can makes its way along the top of the shingle, and leak into your home.


Skylights can create a great ambiance in any home, but a downside is that because they interrupt the continuous roof surface, they are a common contributor of leaking roofs. Water rushes down a pitched roof (or immediately collects on a flat one), builds up in the skylight, and eventually finds a place around the flashing where it seeps inside, and onto your head.

Whether you want to learn more about places your roof might leak, or if you’re interested in a roof leak repair estimate, don’t hesitate to contact Hercules Roofing, your Boca Raton, Florida roofing experts!

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