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This article explains how gutters are attached to or supported on buildings, describing different sorts of gutter hangers and their pros and cons. We also discuss the recommended sized or capacity of roof gutters as a function of the size of roof area being drained. This article series discusses how to choose, install, diagnose & maintain roof gutters & downspouts, & roof drainage systems to prevent building leaks and water entry.
We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
How Are Gutters Attached to the Building? Types of Gutter Hangers
[Click to enlarge any image]
Gutters won't survive the occasional extra weight of water, wet leaves, ice or snow that weigh down gutters when they have not been kept cleaned. But you can increase the durability of the building's roof gutter system by using enough connections to fasten the gutters to the structure so that those occasional extra stresses can be endured.
The sketch at left informs us that
Roof gutters should slope at least 1-inch in every 200 inches of run
Roof gutters should be secured to the building every 2-3 feet.
Four-inch gutters are good for relatively small roof
areas; however, five-inch gutters are preferred because of their additional capacity. Five-inch
gutters are also less likely to allow water to overshoot the gutters when the water is draining
off a steeply pitched roof.
While "rules of thumb" for both gutter size and number of downspouts needed often are based simply on the length of roof edge that is being drained, this approach is flawed in that it fails to consider the total roof area that is being drained.
A roof that is very small in total area, even if very long, may get along just fine with a smaller 4-inch gutter, while a much larger roof area with the same length of roof eaves needs a 5-inch gutter or larger.
Also, as our (photographs below illustrate) odd roof shapes or complex multiple roof designs may end up sending a large volume of water from multiple surfaces into a relatively short gutter length that cannot possibly handle that volume. The result will be spillage by the building foundation and a high risk of a wet basement.
Some homeowners install larger gutters and leaders not because of difficulty handling the volume of water being drained, but because they believe that they'll have to clean the gutters less often. Nevertheless, it doesn't take a much larger handful of leaves or debris to clog a large downspout than a smaller one.
Before Installing a Larger Gutter System: Things to Check if Your Gutters are Overflowing
Double check that the overflow is not gutter back-flow due to a gutter or roof drip edge installation error
Check that the gutters are not loose and pulled away from the roof edge
Check that water is not "overshooting" the gutter, especially at or below roof valleys
Check that the gutters slope properly towards downspout drains
In sum, if the area of roof being drained is larger than usual and there are no defects in the gutter or downspout system, then if gutters still overflow during heavy rainfall you may need to install a larger gutter system.
Also see DRIP LINES INDICATE OVERFLOW This article describes ground-level visual clues that tell the story of the history and location of gutter overflows at a building.
Roof Gutter or Eaves Trough Inspection & Repair Articles
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-747-7747 or by Email: firstname.lastname@example.org
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Certainteed Weatherboard fiber cement siding and trim products - see certainteed.com/ or see certainteed.com/resources/sidingandtrimspecsheet.pdf
"Flashing: the plain solution to leaky walls", Thomas E. Remmele, Manager, Technical Services, Sto Corporation, Building Standards, November/December 1999 p. 21-25.
"Weather-Resistive Barriers [copy on file as /interiors/Weather_Resistant_Barriers_DOE.pdf ] - ", how to select and install housewrap and other types of weather resistive barriers, U.S. DOE
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones