Seamless Gutters and Guards Sized for Chicago Storms

Choosing seamless gutters: 5-inch or 6-inch K-style

K-style gutters have a flat back and a front shaped like crown molding. The size is the width across the top. Five-inch K-style is the long-time residential standard and suits many ranch and split-level roofs. Six-inch K-style holds and moves noticeably more water and pairs well with 3-by-4-inch downspouts, which have twice the opening area of standard 2-by-3s.

Size by the roof, not by habit. Sizing methods published by the sheet-metal trade combine the roof area draining to each gutter, a factor for pitch (steep roofs deliver water faster), and local rainfall intensity. In practice, six-inch gutters make sense for large or steep roof planes, long runs, valleys that dump concentrated water into one spot, and homes where gutters overflow in summer storms even when clean. Adding a downspout often helps as much as upsizing the trough.

Half-round gutters on older homes

Half-round gutters are semicircular troughs carried on exposed brackets, usually in copper or painted aluminum. They suit Tudors, Victorians, bungalows and other older homes where a K-style profile would look out of period. They carry less water than a K-style of the same nominal width, so sizing up is common. Half-round is often fabricated in sections rather than rolled on site, so soldered or sealed joints are part of the system, and the brackets are a visible design element worth choosing deliberately.

Gutter aluminum thickness, hanger spacing and pitch

Gutter aluminum is sold by thickness in thousandths of an inch. Budget gutters often use .027-inch coil; heavier .032-inch coil stands up noticeably better to ladders, hail and the weight of ice. In a snow climate the heavier coil is worth its modest extra cost.

Hangers matter as much as metal. Hidden hangers screwed through the gutter into the fascia and rafter tails, spaced roughly every two feet or closer, hold far better than old spike-and-ferrule fastening. Each run should fall slightly toward its outlet, enough to drain without looking crooked on the house, and long runs usually get a downspout at each end with the high point in the middle. If the fascia board behind is soft, replace it first; our soffit and fascia work covers that, and our gutter installation page covers downspout placement and how we size and hang a new system.

Gutter guard types compared: screens, micro-mesh, hoods and inserts

• Screens: perforated aluminum or plastic sheets laid over the gutter. Inexpensive and good at stopping leaves, but seeds and pine needles can lodge in the holes.
• Micro-mesh: fine stainless-steel mesh over a supporting frame. It blocks nearly everything, including shingle grit, and handles needles well. It needs an occasional brushing, and its tiny openings are the most likely to glaze over with ice.
• Reverse-curve (surface-tension) hoods: a solid cover with a rounded nose. Water follows the curve into a slot while leaves slide off the front. They work best on moderate pitches, can overshoot in very heavy rain, and tend to grow icicles at the nose.
• Foam and brush inserts: fill the trough itself. Cheap and easy to fit, but they trap fine debris and hold moisture.

No guard is maintenance-free. The right one depends on the trees over your roof, the pitch, and how the guard attaches. Guards that slide under the first course of shingles or fasten through them can break the shingle seal, so check the shingle manufacturer’s guidance first. We look at the trade-offs in more depth in are gutter guards worth it.

How gutters and guards behave in ice and snow

Winter is where guard claims meet reality. When warm attic air melts roof snow, the meltwater runs down to the cold eave and refreezes. On an open gutter, ice fills the trough and can build back up under the shingles. With a guard, the same meltwater may freeze on the guard’s surface instead, sending later melt over the front edge as sheets and icicles.

That doesn’t mean guards cause ice dams; heat escaping from the house does. It means guards can’t cure them. Sealing attic air leaks, adding insulation and balancing ventilation reduce meltwater at the source, and heated cable along the eave and in downspouts is a stopgap for chronic trouble spots. If ice dams are a recurring problem, read our ice dam guide before buying guards.

How it handles Chicago-area weather

Care and maintenance

Clean open gutters at least twice a year, after the spring seed drop and again after the leaves fall, and more often under oaks, maples or pines. Flush each downspout with a hose; a clog at an elbow is the usual reason water spills over the front. Check that hangers are tight and that each run still falls toward its outlet, since snow load and leaning ladders can bend a section flat. With guards, brush or rinse the top surface once or twice a year, because fine mesh can collect a film of pollen and shingle grit that slows water.

Seamless Gutters and Gutter Guards: common questions

Do I need 6-inch gutters?

If your gutters overflow in heavy rain even when clean, or large, steep roof planes and valleys empty into a single run, probably yes. Many homes do fine with 5-inch gutters and one more downspout.

Will gutter guards stop ice dams?

No. Ice dams come from heat escaping into the attic and melting roof snow. Some guards even make icicles more noticeable. Fix insulation and ventilation first, then choose a guard for leaf control.

Are seamless gutters better than sectional gutters?

For most homes, yes. Fewer joints mean fewer places to leak and a cleaner line along the roof edge. Sectional gutters still make sense for small repairs and for profiles such as half-round that are often supplied in pieces.

Should I replace my gutters when I replace the roof?

Not always, but it is the easiest time. The roof edge is open, old hangers come out cleanly, and damaged fascia can be fixed before new gutters go up. Gutters that are fairly new and in good shape can usually be taken down and reset instead.