Occasionally, gutter seams or joints open, producing major leaks. Knowing how to repair plastic gutter seams early on reduces the chance of further damage and, possibly, a major repair. Repairing the seal in a plastic gutter seam will keep the water from pouring into your woodwork.

1

Wash the seam area of the gutter.

Clean the repair area to remove any grime or debris.

2

Prepare a tube of exterior-grade polyurethane caulk.

Cut the tip off the caulk tube nozzle at a point where it produces a bead large enough to fill the crack. Start small — you can always make the hole bigger. A 1/4-inch bead is large enough for most cracks. After you cut the tip, you have to puncture the seal in the end of the caulk tube using a stiff wire or long nail.

3

Apply a bead of caulk along one of the cracks.

To apply the bead of caulk, move the caulk gun at a measured pace along the crack and using continuous light pressure on the gun trigger.

4

Smooth the caulk.

You can use a craft stick, plastic spoon, or wet finger to create a smooth surface.

5

Caulk the remaining cracks following the same procedure.

Caulk on all cracks between gutter pieces.

6

Clean the caulk tube.

Wash away any caulk remaining on the gun, your hands, or other unwanted places before it dries.