When the roof shingles do not extend past the metal drip edge the water will suck back on the metal drip edge this is called capillary action and run behind your gutters.
Water falling behind gutter.
Water gets behind the gutter if water is dripping behind your gutter it s probably because it was installed without any flashing over the back of the gutter.
This can be frustrating and also creates a dangerous situation on porch steps during freez.
There are a few elements that come into play that cause water to run behind the gutter.
For example most ranch style homes have a 3 12 or 4 12 pitch roof.
The gutter apron will prevent the dripping.
The first cause is when the roofing material is installed many roofers will not extend the roofing material past the roof edging or drip edge.
This problem is common with homes that have roofs that do not have much pitch to them.
Incorrectly sized poorly adjusted or shoddily fastened gutters can lead to excess space between the gutter and roof which will lead to water falling in between.
Rain water that falls behind your gutters and over the edge of your house can lead to water damage costing you hundreds of dollars in repairs.
Have rain water dripping out from between your facia and gutters.
This may be a direct result of an incorrect fall a common gutter problem that occurs when the gradient of the standard guttering is too level for the water to flow through.