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water behind gutter

I'm trying to figure out how water runoff from the roof could get behind the gutter. The area is on a shed dormer with a drip edge vent. I see water collecting at the bottom of the gutter where it sits against the fascia. It then runs down the face of the board to the bottom and drips off. The area is at the peak of the gutter. I removed the screws holding the gutter on in this area thinking water may be running off the roof onto the support bracket and down the screw, but that did not seem to fix it. I tried pulling up on the drip edge and could not see water running down behind it. Thoughts?

Re: water behind gutter

This is a common problem with gutters, especially vinyl gutters, as they tend to bend out away from the fascia screws holding them to the fascia.

Often, the 1st row of shingles applied to the dormer are installed with little or no overlap & the water curls under the shingle & runs down the fascia.

There are at least 2 ways to fix this:

One way is to install a 45 degree angle metal gutter apron (metal flashing); one end slipped under the 1st row of shingles, & secured as noted below; the lower part overlapping the back of the gutter, so that water will flow into the gutter; this would require removing the spikes or hangers holding the gutter & using the spikes or hanger screws to attach both the gutter & the lower part of the flashing.

Another relatively simple fix is to insert a thin flat piece of aluminum or vinyl flashing that measures 3" deep X the width of the dormer SO THAT THE LOWER EDGE OF THE INSERT IS WELL OVER THE MOUTH OF THE GUTTER, allowing the water to drip directly into the gutter.

To secure the end being tucked under the shingles, if the shingles are new & flexible, pre-drill holes into the aluminum/vinyl pieces & nail or screw the flat piece to the sheathing; exterior deck screws with a drill can be used; a brief heating of the shingles with a propane torch is sometimes needed in cold weather.

If the shingles are old & brittle, or won't bend, don't attempt to bend them, especially in cold weather, you'll only break them; butter the edge of the flashing with black roofing cement & slip it under the 1st row of existing shingles.

Any shingles that ARE torn or broken in the repair process can be re-attached to the roof by buttering the backs of the pieces & placing the pieces back in their original position.

The home improvement stores sell the metal/vinyl flashing sections in 10' sections in various shapes at a reasonable price; a piece of vinyl siding could even be used, if cut to the right dimensions.

Re: water behind gutter

Thanks for the reply. After I posted the question, I was at HD and asked someone in the roofing area. We thought that what was happening is since the slope of the shed roof is so shallow that the water runs around the edge instead of dripping off and since its vented, in some places the water runs through the vent slits and to the house side of the metal, then comes in contact with the fascia and runs down behind the gutter. I bought a roll of 6 inch aluminum flashing and cut some strips 3 inches by about 1 1/2 foot sections an slid it up behind the drip edge and in front of the back edge of the gutter. I could see the water running right out from behind the drip edge and down the new flashing. Problem solved.

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