Gutters should be cleaned at least twice a year, preferably in spring and fall. If you plan only one cleaning, it's most practical to do it in the late fall after the trees have shed their leaves.
Pick a dry day so leaves and small twigs can be removed by hand or with a handheld blower that may have an attachment designed for this purpose.
Be prepared to remove encrusted layers of leaves and other debris from the gutter trough. If you encounter this kind of buildup you may wish to tackle it a little while after a rain when the material is damp. Or you can always hose down the debris. Be careful however not to drive the packed debris into the downspouts where it may become lodged.
While you are removing debris, check for corrosion, holes, dents, sagging and leaking areas and missing, loose or bent hangers or spikes. Mark problem areas with painter's tape so you can spot them when you are ready to make repairs.
Clean the gutter around the downspout area first because this is the place most likely for debris to collect.
Gently flush your gutters with a garden hose or a gutter cleaning tool after you have cleaned them. This will verify whether your gutters are draining well or if they are holding standing water, which contributes to many gutter problems.
Get rid of standing water by increasing the grade of your gutter to create and maintain the proper drain slope. Gutters should slope downward at least 1/4" for every 5'-10' of gutter.
You'll probably be able to adjust the grade simply by bending the hangers. However, it may be necessary to take down an entire gutter section and remount the hangers.
Sometimes hangers have outlived their usefulness and need to be replaced.
If gutters are sagging, it is likely that the nails holding the hangers, or the spikes holding the gutters, have loosened and backed out. This may be corrected by resetting the nails or, if they won't hold, replacing them with screws.
Spikes can't be replaced with screws. In extreme cases it may be necessary to re-nail the spike slightly to the side, above or below its original hole. Seal the old hole in the back of the gutter with gutter sealant.
If the hangers are solidly in place but the gutter still droops, it may be the gutter is exposed to an undue amount of weight. The hangers can often be bent to put the gutter back into position.
If a downspout is clogged, work to loosen debris from the bottom of the downspout or you may pack it tighter. You may be able to unstop the downspout by using water pressure. Run a garden hose up into the spout from the bottom. Turn the water on full blast and watch to see if water starts coming out the top.
If this doesn't work, try a plumber's snake, also running it up from the bottom. Finally if all else fails, take off the downspout and poke around inside to find the reason for the clog.
If you have rust in the gutter, check to see if it's surface rust or if the rust is eating through the metal. You can easily determine this with a piece of sandpaper. Where you see the rust, sand it down. If it's just surface rust, you can remove it with just a little sanding. If the rust goes deeper after just a little sanding then the rust is eating into the metal and need to be replaced.
If the gutters have surface rust and if the joints are still soldered, then the gutters probably don't leak. If the rust is eating into the metal, then your only real solution to keep the gutters from leaking is replacing the gutters.
I'm a CREIA certified home inspector. I have built Hammond Inspection Services to be more than just an inspection company. I started this blog to be more of a resource to home buyers, sellers and real estate agents.