Materials

Gutter End Cap Types: Left, Right, and How They Fail

Last updated: May 23, 2026 · Reading time ~5 min

Gutter end caps are the metal pieces that close off the end of each gutter run. They come in left-side and right-side versions. Failure happens at the sealant joint over 10-15 years — sealant cracks, water leaks behind the cap. Re-sealing extends life another 5-10 years.

The two types

Left-end cap (closes the left end as you face the house) and right-end cap (closes the right end). Pre-formed pieces that snap onto the gutter terminus and are sealed inside the gutter cavity.

How they fail

The sealant inside the cap dries out over 10-15 years. The first sign is a slow drip from the bottom of the cap during rain. Eventually water finds the joint and runs down the fascia.

Repair

Re-seal: clean inside of cap, apply butyl tape, add gutter sealant. About $50-$100 per cap.

Replace: pop off old cap, slide on new one, seal. About $80-$150 per cap.

Frequently asked

Can I caulk the outside?

Short-term yes (a season or two), but proper repair is inside the gutter.

Do guards affect end caps?

No — guards mount on the gutter, not the caps.

Why do end caps fail more than other parts?

They're a small joint with a lot of thermal cycling and water exposure. Plus they're often last in line for re-seal during cleanings.

Got a specific KC gutter project?

Free quote in 24 hours. No high-pressure sales.

Free Estimate Call (816) 469-9563