Check Gutter Pitch With a Garden Hose Before You Buy Guards

Before a guard goes on, the gutter underneath it has to drain. A guard sits over the trough and only lets water in. If the trough is flat or sags in the middle, water sits in the low spot, and the guard holds that water in place instead of letting it run to the downspout. A garden hose and a helper can show you this in about twenty minutes, and the test costs nothing but the water.

Why the hose beats the eye

A gutter that looks level almost never is. The eye reads a trough against a fascia board that may itself lean, and a run that has settled half an inch over twenty feet can look straight from the ground. Water does not care how the run looks. It takes the path the trough gives it, and a low section holds a little water every time it rains. That standing water is why some guard systems overflow in a heavy St. Louis storm even when the guard itself is fine.

Set up the test

Clear the trough first, and do it from a stable ladder with someone holding the base. Leaves and seed husks can pool water and make the run look worse than it is, so a clean trough gives you the real slope. Run the hose from the far end of the run, the end farthest from the downspout, and keep the stream steady rather than spraying. Have your helper stand at the downspout and tell you when water first appears there and when it stops.

Let the flow run for about two minutes after the first water reaches the downspout. Then shut the hose off and watch the trough for ten minutes. Water left sitting in the trough after the flow has stopped is the result you are looking for. Mark that spot with a pencil on the fascia board just above the trough, and note its distance from the downspout.

Read what the water tells you

• Water reaches the downspout quickly and nothing remains afterward: the run falls the right way and the hangers are holding.
• Water sits in one section and drains slowly: that is a low spot, usually at a hanger that has pulled away from the fascia.
• Water runs past the downspout toward the far end: the run falls away from the outlet, or the outlet is set too high.
• Water spills over the front lip: the trough is overfilled at that point, often because the downspout beneath it is too small or crimped.

Each of these has a different fix, and the hose test tells you which one to look for. A low spot is usually a hanger problem and can often be corrected by resetting the hanger and resealing it. A run that falls away from the outlet is a slope problem that may need the whole section reset. A spill at the front is often a downspout problem, so the elbows and crimps need checking before anything else changes.

Measure the slope

Once you know where the trouble is, measure it. Set a four foot level along the inside back of the trough, then use a tape to check the height of the trough at each hanger, measured from the top of the trough to a fixed reference line you chalk on the fascia. Write the numbers down in order along the run. A run that falls evenly toward the downspout shows a small, steady drop from one end to the other. A run that drops, flattens, and drops again has a sag, and the flat stretch is where water collects.

Be honest about what the numbers mean. A gutter is not built to be perfectly flat, and it should never climb toward the far end. A fall too slight to see can still be enough for water to move, but a flat stretch several feet long is a real problem. If your numbers show one, a guard will hold the same water the trough already holds, and the guard will not cure the sag.

Where the timing matters in St. Louis

Run this test in the fall, before the first hard freeze and before the leaves come down in earnest. Water that pools in a sagging trough freezes there, and the ice adds weight to a hanger that is already loose. Freeze and thaw cycles push hangers out of the fascia slowly, and a run that sagged a quarter inch over the summer can sag more by February. Testing before winter also gives you time to schedule the fix before the weather makes the work harder.

The test is worth repeating in spring after a wet winter, because a loose hanger often shows itself only after the ground has softened and the fascia has taken on water. Do not run the test during a rain you did not plan for, since a wet ladder is a fall risk.

What it costs

The test itself costs only water and a little time. Resetting a hanger or two is usually a small job, and many roofers include it as part of the gutter work. Resetting a long section or replacing a sagged run is priced differently, and you should not accept a single lump number for it. Ask for the work to be itemized: the hangers, the section length, any fascia repair if rot is found, and the downspout work if the outlet is part of the problem. The same itemization helps when you compare guard prices, because a guard cannot be priced honestly over a run that still needs its slope set.

Some of the work depends on what the test finds. A run with one loose hanger is a different job from a run that has sagged along its whole length, and a quote that lists both as "gutter repair" hides the difference. Ask the contractor which hangers they expect to reset and how many feet of trough they expect to replace before any guard goes on.

What to ask

Before you pick a guard, ask any roofer or gutter contractor these questions, and ask for the answers in writing.

1. Will you measure the pitch and the hanger heights before you quote the guard?
2. Which hangers will be reset, and what happens to the fascia behind any hanger that has pulled loose?
3. Does the quote name the downspout sizes and show where each outlet drains?
4. If the run sags, is the reset included in the guard price or listed on its own line?
5. Who checks the run after the guard goes on, and when?

If you want a second set of numbers, call Keys Roofing at (314) 220-2333 and ask for the measured slope and hanger heights on paper before you decide on a guard. A written measurement is something you can compare, keep, and show to any other contractor you call.