A leaky rain gutter is never much fun and the problem is you won’t know if you have a problem until it starts raining or you happen to notice while cleaning out your gutters.
If you have old gutters they may be made of galvanized steel and over time they can rust however even new aluminum and vinyl gutters can get leaks.
Visual Inspection
The easiest way to find a leak is by visual inspection.
If your rain gutters are giving you a problem then follow the path back from the ground inspecting your down spouts and gutter system to its end point.
The problem areas are often at seams where two pieces are joined with poprivets and sealent.
When inspecting your down spouts make sure you check the bended area of tubing closely. This is a place where debris will build up and cause corrosion of the metal.
If you have different types of metal pieces used for your downspouts and your gutters you may find that dielectric corrosion has occurred. This will also happen if your fasteners are of a different metal type.
Corners inside and out will also hold debris like rotting leafs that can damage metal parts and also cause overflows.
Finally your seams and end caps.
This is one of the areas that is more difficult to inspect because they are held in place with poprivets or screws and also by sealer. A quick inspection might miss problems in these areas so inspect them closely and use a garden hose to test the connections.
Testing with your garden hose
As a last resort after cleaning your gutter you can plug the downspout with a plastic trash bag and fill the gutter with water.
Your gutter mounts should be in good condition because they will have to carry the weight of the water which may be more then an average rain fall.
After a few moments you will find where the leak is coming from and you will be ready to make your repair.
Making Repairs
If you find that you have a bad connection at a seam, downspout connector or end cap and the metal is in good condition you can make the repair without replacing parts.
If you find that the metal is deteriorated at a connection or in the center of the part then you should think strongly about replacing that section of gutter because you are likely to have more problems later if you simply patch the area.
To make your repairs you will need
A drill with 1/8th inch drill bit to remove the pop-rivets
A screw driver or 1/4 inch nut driver if sheet metal screws were used.
Gutter sealer to seal the connection.
Pair of pliers to straighten the metal.
Aviation tin snips to cut any new pieces that need to be fitted.
Repairing a downspout
If you find a problem with a downspout it is best to just replace it. Patching a downspout never seems to work well even if you cut away a section and mend it with new downspout you will endup having to purchase a full length of downspout anyway so just remove the old and install the new.
It is your choice to keep any bent pieces but in good practice you should probably replace those parts too.
If you have a leak on a long section of downspout make sure that the top section is inserted inside the lower section at their connections. This is a very common mistake. Remember water flows downhill so you always want the water to flow inside of the new lower piece you do not want the top piece wrapping around the outside of a lower part.
End Caps and Corners
End-caps and corner pieces are relatively easy to replace the trick is getting behind the part in the case of a corner to get the pop rivets out and new ones back in.
You may find that supporting that section of gutter with bungie cords connected to your hangers will allow you to remove the section from the hangers and work on it.
Gutter systems are pretty strong but bending can cause kinks so this could be a two person job.
To replace the part drill through the pop rivet head centers and they will come out with relative ease.
Clean all sides of the connection and coat the overlaping section with sealer before reattaching the part with new pop-rivets.
Once the part is installed you will need to apply a thick coating of sealer to the inside gutter surface to help repel water from the connection point.
Midspan leaks
Leaks in the center of your gutter are more difficult to repair. The reason being is manufacturers will use different profiles to form the gutter. Even a close match can be off just enough to make the connections harder to make then just repairing a section of gutter in place.
If you have a small leak you can use gutter sealer and a piece of like metal .. Aluminum for aluminum gutters.. and make a patch in the bottom or side of the gutter.
If you find you have a lot of pin holes on the bottom of your gutter then you should think about replacing the whole section of gutter from end to end.
Final Note
The choice to replace vs repair a badly damaged older gutter is pretty simple.
If your gutter is in bad condition due to corrosion then definitely look into replacing as much of it as necessary or installing a whole new system.
The cost for parts is not that great and the skills to perform the install are no more then the skills needed to make major repairs.