Chapter 01Records · System
Gutter and downspout record
Sketch the house, name every gutter run and measure each one from the ground. The gutter tool turns length, roof depth and pitch into an area: a 5-inch K-style gutter is rated for 5,520 sq ft, and one 2 by 3 inch downspout for about 600, so count the spouts each run needs against the ones it has. Delaware's DNREC says to clear gutters about twice a year, in spring and early fall, and whenever they clog, and to keep downspouts pointing away from the house. Book those two dates, write a line after each visit, and note any run that spills in a storm. Ladder and roof-edge work goes to a gutter company or the landlord.
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026; Delaware DNREC I-ADAPT, Clean Gutters, checked October 17, 2026.
- Gutter cleanings: spring and early fall, plus any clog (DNREC)2 a year Delaware DNREC I-ADAPT, Clean Gutters, October 17, 2026
- Roof one 2 by 3 inch downspout handles (This Old House)600 sq ft This Old House gutter and downspout sizing guide, October 16, 2026
- Run length that gets at least two outlets60 ft This Old House gutter and downspout sizing guide, October 16, 2026
Do it, skip it or get help
Measure, size and log it yourself
Everything here happens on the ground or at a window. You need a tape, a sketch, the gutter tool, a calendar and the log page.
Skip it if the gutters aren't yours to manage
In an apartment or a condo where the building looks after the roof, skip the sizing and the cleaning dates. Keep the spill notes and send them to the manager.
Cleaning, hanging and adjusting go to a gutter company
Clearing a gutter, adding a downspout or changing the slope is ladder and roof-edge work. DNREC names a gutter cleaning company as the one to contact, and renters go to the landlord. This page keeps the numbers and dates you hand them.
Source: Delaware DNREC I-ADAPT, Clean Gutters, checked October 17, 2026.
The steps, in order
Sketch the house and name each run
Draw the roof from above and mark every gutter run with a name: front, back, garage, porch. Put a dot where each downspout comes down.
Have ready: The run sheet, a pencil and a walk around the house
Measure each run from the ground
Tape each run between ground marks under its two ends. Halve the gable width for the roof depth and count siding rows for the rise, as the measuring guide shows.
Have ready: A 25 ft tape, a helper and two stakes or stones
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
Run the numbers in the gutter tool
Enter length, depth and rise for each run. The tool applies the pitch factor and checks the area against the gutter's rating: a 5-inch K-style takes 5,520 sq ft. Copy the answer onto the run sheet.
Have ready: The three numbers for each run
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
Count the downspouts each run has
Compare the tool's count with the dots on your sketch. One 2 by 3 inch downspout handles about 600 sq ft and a 3 by 4 inch about 1,200, and a run of 60 ft or more gets at least two outlets. Circle any run that is short.
Have ready: The sketch with the downspout dots
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
Note where each downspout lets out
Stand at the bottom of each downspout and write which way the water goes. DNREC says downspouts should point away from the house and the lawn should slope away so water doesn't pool by the walls. Write "toward the house" or "pools here" if that's what you see.
Have ready: The run sheet and a phone for a photo of each outlet
Source: Delaware DNREC I-ADAPT, Clean Gutters, checked October 17, 2026.
Book the spring and early fall cleanings
DNREC says to clear gutters about twice a year, once in spring and again in early fall, and any time they clog. Put both dates on the calendar and book the gutter company or ask the landlord.
Have ready: The calendar and the gutter company's number
Source: Delaware DNREC I-ADAPT, Clean Gutters, checked October 17, 2026.
Watch one heavy storm from inside
From a window or a covered porch, write which run spills and where: near the downspout, partway along or at an inside corner. Too much rain, too few downspouts and a clog are the usual three causes.
Have ready: The overflow page and a phone for a short video
Source: Able Roofing, why gutters overflow, checked October 16, 2026.
Write a line after every visit
Date, who came, which runs they cleared and anything they found or changed. Add new downspouts to the sketch the same day.
Have ready: The cleaning and visits page
Print the working copy
One page, black and white, US Letter. Tick the boxes and write the dates in.
- House sketched, every run named
- Downspouts marked as dots on the sketch
- Each run taped between ground marks
- Roof depth and rise noted for each run
- Each run sized in the gutter tool
What goes wrong
The downspouts never get counted
On most house runs the downspouts run out before the gutter does. A run draining 660 sq ft through one 2 by 3 inch downspout, rated for about 600, can spill even when it is clean. The run sheet shows that before the first storm does.
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
The pitch gets left out
This Old House lists ignoring roof pitch as a common sizing mistake. A 6 in 12 roof adds a tenth to the area, which is enough to push a run past one small downspout.
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
Nobody knows when they were last cleaned
Without a date, "we did them last year" can mean two years. DNREC says spring and early fall, and the log shows at a glance whether both happened.
Source: Delaware DNREC I-ADAPT, Clean Gutters, checked October 17, 2026.
A downspout empties against the wall
A clean gutter still sends the water somewhere. DNREC says clogged gutters can overflow in front of a basement window or along the foundation, and that downspouts should point away. Note any outlet that doesn't, and hand it to the gutter company.
Source: Delaware DNREC I-ADAPT, Clean Gutters, checked October 17, 2026.
A spill gets noticed but not written down
"The back gutter overflows sometimes" gives an installer nothing to work with. The run, the spot, the date and how hard it rained let them tell a clog from a missing downspout.
When the steps change
Renting a house
Measure and log the same way, but the cleaning dates and every fix belong to the landlord. Send the run sheet and any spill notes in writing and write down the date you sent them.
Trees over the roof
Able Roofing says nearby trees or especially rainy weather can mean cleaning more often than twice a year. Add a third date after the leaves drop and note which runs fill fastest.
Source: Able Roofing, why gutters overflow, checked October 16, 2026.
An upper roof drains onto a lower one
Add the upper roof's area to the run it spills onto, as extra roof in the tool. That run often needs the bigger downspout, so give it its own line on the run sheet.
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
Half-round gutters
Half-round is rated for less at the same width: 2,500 sq ft for the 5-inch and 3,840 for the 6-inch. Write the shape on the run sheet so the tool checks the right rating.
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
Tips and tricks
- Tip 01
Name the runs the way the installer will
Front, back, garage, porch. Write the same names on the sketch, the run sheet and every visit line, so a phone call needs no map.
- Tip 02
Photograph each downspout outlet once
One photo per outlet, taken the day you make the sketch, shows where the water went before anything changed.
- Tip 03
Book the fall cleaning after the leaves drop
Early fall is the target, but a date set too early can mean clearing the gutters before the trees are done. Look at the trees over the roof when you pick the day.
- Tip 04
Keep the tool's printout with the run sheet
Print the gutter tool's result for each run and clip it behind the sheet. The installer sees the area, the pitch factor and the count in one place.
- Tip 05
Ask what they found
After a cleaning, ask which run had the most in it and write it down. Over a few years that tells you which trees to watch.
What we would do
Do the sketch and the count this weekend, then book spring
Print the free page, walk around the house once, and run each gutter through the tool. If a run is short on downspouts, put that in front of the gutter company when they come for the cleaning, so one visit covers both.
The tools and guides in this system
Chapter 01Gutter and downspout sizingMeasure a gutter run and its roof from the ground, apply the pitch factor, and get the gutter size, downspout count and slope, plus a printable gutter log.Open the tool
Chapter 01Home service logTurn the last visit for your heating, cooling, chimney and septic service into the next due date and a book-by date, then print a log of who to call.Open the tool
Chapter 05Home maintenance calendarPick your climate region, say whether you own or rent and tick what the house has. Get a year of household jobs by month and a year sheet to print.Open the tool
Know-howHow to measure a gutter run and its roof from the groundThree numbers per gutter run, all taken on the ground: the run's length, how far the roof reaches back, and its rise. Then the pitch and the area.Read the guide
Problem-solving guideGutter overflowing in heavy rain: what to write downWatch one storm from a dry spot, note which run spills and where, then check its downspouts against the roof area. Take that note to an installer.Read the guide- Chapter 01All records toolsPrintable home records with a calculator behind each one: appliance and warranty log, HVAC filter sizes and change dates.Open the chapter
Questions
How often should gutters be cleaned?
Delaware's DNREC says about twice a year, once in spring and again in early fall, and any time they clog. Able Roofing adds that trees nearby or a very rainy climate can mean more often.
Source: Delaware DNREC I-ADAPT, Clean Gutters, checked October 17, 2026; Able Roofing, why gutters overflow, checked October 16, 2026.
How many downspouts does a gutter run need?
Divide the run's pitch-adjusted roof area by what one downspout handles: about 600 sq ft for a 2 by 3 inch and 1,200 for a 3 by 4 inch. Round up. A run of 60 ft or more gets at least two outlets either way.
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
What size gutters does my house need?
Most house runs fit a 5-inch K-style gutter, rated for 5,520 sq ft of drainage area. A 40 ft run under a 15 ft deep, 6 in 12 roof drains 660 sq ft after the pitch factor, well under that. The gutter tool does the arithmetic for each run.
Source: This Old House gutter and downspout sizing guide, checked October 16, 2026.
Which way should downspouts point?
Away from the house. DNREC also says the lawn should slope away so water doesn't pool next to the building. If an outlet points at a wall or water pools there, write it down and ask the gutter company or the landlord.
Source: Delaware DNREC I-ADAPT, Clean Gutters, checked October 17, 2026.
What should I write down after a gutter cleaning?
The date, who did it, which runs they cleared, what they found and anything they changed, such as a new downspout. Add any change to the sketch the same day.
The primary source
I-ADAPT Exterior Adaptation: Clean Gutters, Delaware Department of Natural Resources and Environmental Control (DNREC), I-ADAPT. Checked October 17, 2026.
The steps on this page follow this source. Other figures cite their own source where they appear.
Other sources on this page
- How To Size Gutters and Downspouts, This Old House. Checked October 16, 2026.
- The Most Common Reasons Gutters Overflow, Able Roofing. Checked October 16, 2026.
See every source on the site on the sources page. Spotted an error? Tell us.