Normal wear and tear as well as a harsh winter can cause the seams of aluminum gutters to spring a leak. It's not too hard to repair these leaks when you realize how the professionals put them together when the gutters are new.
As with many jobs, the success of the project is directly related to the amount of patience you have when it comes to the prep work.
Assemble the ladders and tools required to safely access the leaking gutter. Use wide boards on soil to support step ladders. Obey all the safety recommendations that are printed on the ladders. Place the ladders so you don't have to reach out beyond the ladder to make the repair.
Visit a hardware store or home center that sells aluminum gutters to locate the required gutter repair sealant. Wholesale roofing supply houses that sell asphalt shingles usually are an excellent source of high-quality gutter repair products.
The manufacturers of aluminum gutters make a special sealant that's been tested to produce leak-free gutters for years. You want to buy this product. Don't assume caulk of any type, even if it says it's for gutter repair, is the best thing to use.
Once you have the proper sealant, stop and read the instructions on the label. They will say to apply to a clean, dry,
grease- and oil-free surface. Clean does not mean hosed out. Clean means clean enough to eat from.
Remove all gunk, leaves, twigs and other debris from the inside of the gutter. Make a solution of soapy water using regular liquid dish soap. Use an old paint brush to apply this solution to the inside of the leaking seam or gutter joint. Dab the paint brush around to create lots of suds. Add more liquid soap if necessary.
Brush, dab and do what's necessary to remove all dirt within six inches of the seam to be repaired. Rinse regularly with clear water until the seam is perfectly clean.
Use old rags, a leaf blower or allow the gutter to dry naturally in the sun. Make sure it's completely dry.
Puncture the seal at the tip of the special sealant and squeeze the tube as you would toothpaste. Sealant can be extremely sticky and have the consistency of honey when the air temperature is about 75 degrees.
Apply the sealant so it spreads out about one-half inch on both sides of the seam that's leaking. Don't try to use a stick. Move the tip of the tube around to spread the sealant. The sealant starts to skin over quickly, so you must work fast. Use the tip of the tube as a spreading device to help the sealant stick to vertical parts of the gutter.
Apply the sealant so it's about three-sixteenths of an inch thick. It seems like it's too much material, but when the sealant dries and cures, much of what you see disappears into the air.
Summary: The application of the sealant is the easiest part of the project, but it's imperative you put on enough material. If you want to see how much material disappears into the air, do a test on a scrap piece of aluminum foil the day before you attempt this project. Leave the test piece of foil out in your garage to dry. Because the fumes are unpleasant, do not do this test inside your home.
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