Stop the drip: Fix a leaky eavestrough

Leaky eavestroughs can create a wide variety of problems, from simple nuisance drips to serious foundation leaks. The good news is that fixing them is relatively easy.

Joint leaks
If the leak is at the joint of two pieces, make a repair using roof-repair caulking or construction adhesive. Clean the leaky area with a wire brush and then cover the hole or split seam with the caulking. Smooth the caulking flat with a putty knife. Schedule the repair according to the weather so the caulking can dry for at least a day before being exposed to water.

Repairing sections
If a whole section of eavestrough needs to be replaced, because it’s dented or damaged in a serious way, begin by cutting away the damaged section using tin snips. (Be sure to wear gloves to protect your hands from the sharp edges as you work.) Cut a new section to fit, overlap the seams and clamp it in place. Next, drill pilot holes before riveting it together. Large interior patches can be made using rolled aluminum to make the required patches: just rivet them in place before sealing the edges of the patches with caulking.

Flat spots and sags
Over time, eavestroughs will often sag and stop draining properly. Fix sags and flat spots in long runs by first marking a level line across the length of the section with a string level, and then adjusting the trough to run at an angle toward the nearest downspout.
The outlet end in the run should be a minimum of 1/8″ lower for every 10′ of length. To eliminate flat spots, the eavestrough’s slope should be consistent across the length. Replace loose or missing spikes and ferrules as required to prevent future sags.