Copper Gutters in St. Louis: What the Metal Costs You Later

Copper gutters are the choice a St. Louis homeowner can watch change over the years, and some people pick them for that reason alone. The metal costs more than aluminum, weighs more, and does not need the paint refresh that aluminum does. What decides whether a copper run lasts is less the trough itself and more what the trough touches, how its joints are made, and what holds the downspouts. This page covers those points so you can ask the right questions before you set a copper bid next to an aluminum one.

Gutters and guards

Copper and aluminum should not share water. Rain that runs off copper carries a little dissolved copper with it, and that water attacks any aluminum or galvanized steel it passes over. A copper trough hung on steel brackets, or fastened with aluminum straps, will show the damage on the lower metal first, usually at the fastener or the bracket. The pattern that avoids this is copper hangers, copper or stainless fasteners, and copper straps on copper downspouts, with no aluminum part in the path of the water.

Copper also stains what it drains onto. As the surface weathers, the runoff takes on a green or brown tint, and where it lands on limestone, a painted porch rail, a light brick course, or a stucco kick, it leaves a mark that does not wash off easily. If a downspout discharges onto stone or a lighter wall, a splash block, an extension or an underground line should be part of the same bid, not a later fix.

Copper moves less with temperature than aluminum does, but a long run still moves. The usual method is to fix the run at one end and let it slide at the other, so the trough is not forced to take up its expansion at the corners. Corners, end caps and outlets are where copper runs are most likely to leak, because those spots are joined rather than continuous. A long run can be made with fewer seams, but the corners still need joints, and the joint method is worth asking about before you compare prices.

In St. Louis the freeze and thaw cycle loads a gutter in two ways. Ice that forms inside the trough presses outward on the seams and the front lip, and a sudden thaw can release it all at once. Hail season, which runs through the spring and into early summer, dents soft metal, and copper dents too, although the surface can hide the dent until the patina forms over it. A copper trough hung on hangers spaced too far apart will sag under a heavy ice load, and a sag holds water, which then freezes again in the same low spot.

The downspouts set how long the run lasts

Copper troughs are often quoted with the downspouts as an afterthought. The downspout carries the most water on the run, takes the hardest knocks from ladders, hail and winter ice, and is the part most likely to be bumped by a mower or a trimmer. Ask whether the downspout is the same weight as the trough, whether it is held by a copper strap at each run, and what sits at the bottom. A copper downspout that ends in an aluminum elbow has moved the galvanic joint to the place where water pools and sits.

What it costs

Copper is priced by the weight of metal and by the labor to form, fit and join it. A copper bid usually runs well above an aluminum bid for the same footage, and the gap widens on a house with many corners, valleys and outlets, because each one is a separate fabrication task. Two weights are commonly quoted, 16 ounce and 20 ounce copper. The heavier metal costs more and holds its shape better over a long unsupported span, so ask which weight the bid uses and why, and do not set a 16 ounce quote beside a heavier one without noticing the difference.

Copper does not need paint, and over many years that is a real saving that aluminum owners pay for in repainting. The saving only counts if the rest of the system is right. Copper hangers, copper or stainless fasteners, straps, outlet fittings and any splash protection on stone or stucco are separate items, and a bid that says only copper gutter often leaves them out or assumes them. Look for each one by name in the line items.

A failed copper joint is also more expensive to repair than a failed aluminum section. A soldered seam that opens in a freeze has to be cleaned, reopened and resoldered, and that takes more labor than snapping in a replacement aluminum section. Ask who makes the joints, how they are checked before the crew leaves, and whether the bid includes a visual check after the first heavy rain.

What to ask

1. Which weight is the trough, and is the downspout the same weight?
2. What are the hangers, fasteners and straps made of, and does any aluminum or galvanized part sit in the path of the water?
3. How are the seams made, and are the corners, end caps and outlets soldered, riveted or sealed?
4. Where does each downspout discharge, and is there a splash block, extension or underground line for any stone, brick or stucco below it?
5. Which end of each run is fixed, and which end is allowed to slide?
6. What hanger spacing does the bid name, in inches?

Compare the answers line by line against the aluminum bid. The two are easiest to compare when hangers, fasteners, downspout straps and outlet fittings appear as separate items in both. If you want to go through the questions with a crew before you decide, the Keys office is at (314) 220-2333.