Gutters and where the water goes

Roofing and guttering are the same problem seen from two ends. The roof gets water off the building; the gutter and downspout decide where it lands. In a county of subdivisions on graded lots, where the ground was shaped by a machine before the house went on it, where it lands matters more than people expect.

Sizing, which is usually wrong before it is old

A gutter has to carry the water off the roof plane above it in the heaviest rain that plane will see, and the amount of water is a function of roof area and pitch. A steep plane delivers water faster than a shallow one of the same footprint. Standard residential guttering is five inch, and six inch carries substantially more, which matters on a long run, on a steep plane, or where two planes drain into a valley that dumps into one section of gutter.

Downspouts are the other half. Too few outlets on a long run means the water travels the length of the gutter before it can leave, and a gutter running full is a gutter that overshoots at the corners and sags in the middle.

Seamless is not a brand, it is a method

Seamless gutter is formed on site from a coil, on a machine on a truck, and cut to the exact length of the run. The only joints are at corners and outlets. Sectional gutter, sold in lengths and joined every ten feet, has a seam every ten feet, and a seam is where a gutter eventually leaks. Nearly everything hung residentially now is seamless, and if a proposal does not say which it is, ask.

Guards, honestly

Gutter guards are worth having and they are not a promise that you will never look at a gutter again. What they reliably stop is the big stuff: leaves, twigs, the seed load that comes off a maple in a fortnight. What they do not stop is fine grit, shingle granules and roof silt, which passes through any mesh or perforation fine enough to be worth fitting.

Two practical points that follow from that photograph. First, a guard sitting on a worn roof is protecting the gutter, not fixing the roof: the shingles above this one are visibly aged and the guard does nothing about that. Second, the debris does not disappear, it relocates to the top of the guard, where a twig across the holes still narrows the opening and where it has to be brushed off by somebody at some point.

Why the new roof is the moment to deal with the gutters

• Access is already paid for. The ladders, the staging and the crew are on your house. Doing the gutters as a separate job later means paying for the setup twice.
• Drip edge and gutter have to agree. Metal drip edge at the eave should direct water into the gutter, over the back edge rather than behind it. Getting that wrong sends water down the fascia, and it is far easier to get right when both are being fitted at once.
• Old hangers loosen during a tear off. Debris comes off a roof into a gutter whatever anybody does. A run that was marginal before a tear off is often visibly sagging after one.
• Granule silt tells you the roof age anyway. If the crew is pulling handfuls of granules out of the gutter, you have your answer about how much life is left in the shingle above it.

Where the water goes after the downspout

This is the part that gets ignored and causes the expensive problems. A downspout that discharges against the foundation is a downspout that is watering the thing you least want watered. Extensions, splash blocks, or a buried line taken out to daylight all work; the choice depends on the grade of the lot. On the flatter graded lots common in this county's subdivisions, a two foot splash block is often not enough, and the tell is a damp patch that appears in the same corner of a basement after every heavy rain.