InspectAPedia®

Bad downspout connection (C) Daniel Friedman Where do Leaks Occur at Roof Downspouts or Leaders?

  • DOWNSPOUT LEAKS- CONTENTS: Common Leak Points on Downspouts & Downspout Connections - Downspout defects, clogging, overflowing, holes corrosion, leaks that cause wet basements or crawl areas
  • POST a QUESTION or READ FAQs about the cause, repair, & prevention of leaky roof downspouts
  • REFERENCES
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Roof drainage downspout leak points:

This article describes the places where you are most likely to find leaks in the building roof drainage system downspouts or leaders.

This article series discusses how to choose, install, diagnose & maintain roof gutters & downspouts, & roof drainage systems to prevent building leaks and water entry.



Green links show where you are. © Copyright 2017 InspectApedia.com, All Rights Reserved.

Common Leak Points on Downspouts & Downspout Connections

Gutter and Downspout Details (C) Carson Dunlop Associates

Article Contents

[Click to enlarge any image]

Common leak points at downspouts include:

Sketch courtesy of Carson Dunlop Associates.

Downspouts Split by Leaves, Swelling Wet Debris, or Frost

Downspouts may be split and damaged from swelling organic debris (leaves) or by freezing. The result is leaks against the building wall and foundation. Keeping a strainer at the gutter-to-downspout connection will protect the downspouts from becoming clogged and thus splitting.

Split downspout due to frost (C) Daniel Friedman

Split downspout due to frost (C) Daniel Friedman

Of course, if the downspout is connected to a buried drain line that is also blocked, water backing up into the downspout will, in freezing climates, still freeze and burst the downspout.

Downspout Leaks at Connections & Elbows

You might be surprised but the dislocated downspout "connection" shown at below-left is very common. Don't assume that the building's downspouts are all connected - it's worth a close look, especially if there are signs of water entry or dampness in the basement or crawl space.

Bad downspout connection (C) Daniel Friedman

Bad downspout connection (C) Daniel Friedman

At the first photo above right you can see two downspouts descending the building wall. The white round downspout has lost its elbow and extension, and leakage has rotted the building.

In the photo just above, the downspout or leader unit is leaking a bit at the elbow and has damaged the T-111 plywood siding. Look for insect and rot damage at this location.

Gutter and Downspout Details (C) Carson Dunlop Associates

What is the proper direction or "female" end to "male end" of downspout joints?

The sketch at left illustrates the direction of water flow off of a roof - in this case a "flat roof" that drains to two roof scuppers.

The enlarged section of downspout connections (circled detail at lower right in the illustration) explains that downspout section connections and downspout elbow connections need to be installed so that water flow will always be directed to the interior of the next or "down-slope"
downspout component.

Sketch courtesy of Carson Dunlop Associates.

Downspout Extensions that Lack Adequate Slope

Our downspout extension line photos below show what happens if the downspout extension is too flat, or if it ends aimed "uphill" from the downspouts themselves: the downspout extension simply backs up and during heavy rain, spills by the building.

The photo at below left shows a black flexible 4" drain line and tee intended to conduct roof spillage away from the building. But following the drain line we found it ending pointing "up hill".

Bad downspout connection (C) Daniel Friedman

A closer look into the downspout extension connecting tee (below right) shows that the line contained standing water and was not draining.

Bad downspout connection (C) Daniel Friedman

Downspouts Emptying Below Decks & Porches

Downspout spills below deck (C) D Friedman

An often hidden basement water entry problem is traced to a downspout that the building owner thought was safely handled below an attached deck or porch.

On closer inspection we may find that the downspout spills below the deck and against the building, or that an extension has fallen off, or as we show at left, the downspout extension slopes up-hill.

Notice the water stains on the foundation wall near the downspout?

Particularly because many builders construct the deck before final backfill and grading, soil below the deck slopes back towards the building, increasing the risk of basement or crawl area water entry.

Sometimes desperate measures are needed to successfully extend a downspout out from below a deck. The photos below show a combination of a downspout that was spilling below a deck, an inside building corner, and a wet basement (not shown).

Bad downspout connection (C) Daniel Friedman

Under Deck Downspout extension (C) Daniel Friedman

 

Roof Gutter & Downspout Articles

...


Continue reading at DOWNSPOUT DEFECTS, OTHER or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see DOWNSPOUT / LEADER DEFECTS

Or see GUTTERS & DOWNSPOUTS - home

Suggested citation for this web page

DOWNSPOUT LEAKS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

INDEX to RELATED ARTICLES: ARTICLE INDEX to ARTICLE INDEX to GUTTERS & DOWNSPOUTS

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia


...

Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Comment Box is loading comments...

Technical Reviewers & References

Click to Show or Hide Citations & References

Publisher's Google+ Page by Daniel Friedman