Although aluminium gutters provide a great way to drain water off your roof and away from your house, they do tend to develop leaks over time. An aluminium gutter leaks most often when standing water works its way through a seam in the gutter. A gutter leak should be repaired immediately because the potential exists for the leak to grow. Repairing an aluminium gutter leak is usually an easy task.
Clean the area above the leak with a wire brush and water.
Remove any water that is in the leaking part of the gutter. Soak up the water with rags, or brush it out of the gutter and into the downspout.
Allow the area to dry completely. Rub the area with sandpaper.
Cover the hole (or leaking seam) with plastic roofing cement. Apply the sealer liberally with a putty knife so it covers at least two inches around the hole. The excess amount is because the plastic cement will shrink.
Place a piece of sheet metal over larger holes. Place the piece of metal onto the plastic cement that's surrounding the hole. Cover the piece of sheet metal with a layer of plastic cement.
It is best to repair a gutter when it is warm and dry outside.