When plastic gutters have cracks and holes, rainwater can drip onto your house and cause damage. Water can warp wood siding, shutters, window and door frames. It can even erode your house's foundation. Fortunately, repairing your gutters is well within the reach of do-it-yourselfers, so you don't have to wait for an expensive visit from a professional. Seal cracks with caulk and holes with scraps of vinyl. You can purchase vinyl that matches your gutters at the home-improvement store.
Clean the cracked portion of the gutter with a rag and cleaning solution. Clean the inside and outside of the gutter and dry completely.
Apply clear silicone caulk to the crack, inside and out.
Spread the caulk with a putty knife. Scrape away any excess.
Measure the hole and cut a piece of vinyl 1 inch larger than the hole on all sides.
Clean the inside and outside of the damaged area of the gutter. Dry completely.
Apply clear silicone caulk around the hole on the inside of the gutter.
Press the vinyl into place, scraping away any excess caulk with a putty knife.
Don't start this project unless there will be no rain for the next 24 hours. Dry weather allows the caulk to cure properly.