Copper and half-round gutters in St. Louis

Why St. Louis has so much of this

The city was built in brick, block after block, from the 1890s through the 1950s, and the builders hung half-round gutters on it — galvanized on the modest streets, copper on the better ones. Copper doesn't rust, so a hundred-year-old copper half-round on a house in Compton Heights is often still doing its job. What fails is the soldered seams, the outlet where the downspout meets the gutter, the iron brackets that rusted, and the sections a previous owner "fixed" with roofing cement.

Copper gutter repair: St. Louis seams, brackets and outlets

Soldered seams and outlets. Copper is joined with solder, not sealant. When a seam opens, it should be cleaned to bright metal, fluxed, and re-soldered. Caulk on copper is a six-month fix that makes the proper repair harder. Most repairs on copper gutters in St. Louis are this: two or three seams and an outlet, typically $250–$600 depending on access.

Brackets and straps. Half-round hangs from brackets — into the fascia, the roof edge or the mortar joints — with a strap over the top. The originals were steel and they rust through. Replacement brackets in brass, stainless or copper-coated steel on 24-inch centers, with the pitch reset, usually get a decade-old sag draining again.

Sections beyond saving. A run that was hit by a ladder or split by ice is replaced in matching copper, soldered in. Copper darkens to brown within a few years; new sections stand out for a while and then don't.

Downspouts. Round copper downspouts, the elbows that got crushed at the bottom, and the leader heads on the grander houses. The profile should be matched, and the outlet at the bottom moved away from the foundation, which on a city lot with a five-foot gangway usually means a buried line rather than an extension.

What to look at from the ground

You can learn a lot about a half-round system without a ladder. Walk the house on a dry day and then again during a steady rain.

• Green or white streaks on the brick under a seam usually mean the solder joint has opened and water is weeping through.
• A wavy line along the roof edge means brackets have rusted or pulled loose and the gutter is drooping between them.
• Black patches of tar on the copper are an old patch. They often hide a split or a failed seam.
• Water pouring over at one spot can be a clogged outlet. Half-round outlets are smaller than K-style ones and block more easily.
• A downspout that rattles or leans away from the wall has lost a strap.

Write down where each problem is. A contractor who works on copper can tell you more once they are on a ladder, but your notes make the visit faster.

Why caulk is the wrong fix

Roofing cement and silicone stick to copper for a while and then let go, because copper expands and shrinks a great deal with the seasons. Worse, the old patch has to be scraped and burned off before the seam can be soldered, which adds time to the proper repair. If you need a stopgap before a contractor can come, a bucket under the drip is kinder to the gutter than a tube of caulk.

Questions to ask before copper work starts

1. Do you solder copper yourselves, or send it out?
2. What weight of copper will any new sections be?
3. What are the new brackets made of, and how far apart will they go?
4. How will you protect the brick and the roof edge while you work?
5. What happens to any copper that is removed?

Looking after copper and half-round

Clean the gutters with plastic tools, not metal scoops. Keep the outlets clear, since a small outlet clogs fast. Don't paint or coat copper unless you want a different look; the brown and later green finish is what protects it. Check the brackets every few years, because they fail long before the copper does.

Replacing a half-round system

When the whole system is done — usually galvanized half-round that has rusted through, not copper — there are three ways to go:

On a 1920s brick home in Tower Grove South with 120 feet of gutter, aluminum half-round runs about $1,500–$2,400 installed; copper, $4,200–$7,200. Ask for both to be quoted. Half-round vs. K-style compares the profiles, and copper gutters: cost and care goes further on copper.

Historic districts and what your city says

The City of St. Louis has local historic districts — Soulard, Lafayette Square, Compton Heights, Shaw and others — where exterior changes visible from the street can need review, so check with the city's Cultural Resources Office before work starts; swapping copper half-round for white K-style is the kind of change that gets questions. Outside the city, licensing and permit rules vary by city and county — check with your city or St. Louis County before work starts. Kirkwood, Webster Groves and Clayton each have their own building departments.

The scrap question

Copper is worth money, and copper downspouts do get stolen off houses. If a contractor quotes you a replacement in aluminum and offers to "take the old copper off your hands," understand that your gutters may be worth more than the job. Removed copper has scrap value — ask that it be weighed and credited on the invoice, or left for you to sell.

Related: gutter repair for aluminum systems, gutter cleaning for how copper should be cleaned without scratching it, box gutters on older houses, and the Kirkwood guide for the older houses outside the city. Requests from this site go to an independent local contractor partner.