FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Discussion Forum

Discussion Forum

Drainage for my house

erikpeter | Posted in Construction Techniques on June 10, 2006 05:29am

I’m building a house on fairly good soils in an otherwise pretty wet area in Western Oregon.  I’m trying to determine the best configuration for my drains.  The soil engineer said a footing drain is unnecessary, although I will put in a sump in the crawlspace.  The site is very flat (6″ of slope over 150′)  The nearest ditch is 150 feet away. 

–Do I need to pump my gutter drains out to the ditch or will the natural water pressure of the water coming down the downspouts carry the water away? 

–If I do need to pump the gutter drains, can I have them pumped by the sump, or will they backflow into the crawlspace too quickly?

–What type of pipe should I use?  (I was planning to use 3″ Schedule 40 to connect the gutter drains and use 4″ADS to run out to the ditch.)

Reply
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Replies

  1. Piffin | Jun 10, 2006 06:13pm | #1

    The basement sump has two purposes
    one is to catch and dispose of any water that accidentally gets in IF or WHEN the other primary drainage systems fail
    The other - sometimes perforated drain lines under the slab lead to the sump pit in places with a high water table where rising hydralic pressure can lift the slab or leak into the house

    The exterior drians - there are two - completely independent of one another. You need a perimeter drain at or just below footing level, perforated, with a sock to keep it from silting up, surronded with washed 3/4" stone and a landscape fabric or other geotextile to keep the fines out of the gravel. This must lead downhill to daylight, possible the ditch you are speaking of.

    The other exterior drain for the gutter drops is not perforated and should not lead ito the same perimeter drain at footing level. The whole idea of eavestroughs and drains is to lead the water AWAY from the foundation, not to inject it in. I usually run it about two feet below surface, keeping it pitched to drain the way I want it to go too.

    If you cannot lead these to daylight downhill, you need to dig a drywell or a sump pit. Sump will pu,mp up and away. Drywell is a hole about septic tank size. Drystack concrete block in a circle and fill the center with 3/4" stone. Cover with the geotextile to keep fines out, and lead the drains into this, preferably at least 40-50 feet away from the foundation in a dowhill direction. A lot of airspace is left in the drywell that is filed with the water and then gradually disperses it - percolates into surronding soils. But if the water table is too high, a drywell won't work, it'd have to be a sump pit

     

     

    Welcome to the
    Taunton University of
    Knowledge FHB Campus at Breaktime.
     where ...
    Excellence is its own reward!

  2. User avater
    zachariah | Jun 11, 2006 01:07am | #2

    what ever you do, do not drain gutters to a sump in your crawl space!!one of the most costly renovations I have done was to repair massive damage to a 1/2 finished 1/2 crawl space down stairs.sump pumps can easily fail from power outages during a large storm or just plain old mechanical failures piffin's suggestions are spot on.a little extra effort now will reward you later.

    good luck, Z

  3. FlashGordon | Jun 11, 2006 03:00am | #3

    The rule of thumb for drainage pipe is to keep a 1/2% slope for smooth wall pipe like schd 40 PVC and 1% for corrugated pipe like the ADS.  1/2% is equal to 6 inches over a 100 ft run.  Since your lot is flatter than that, your going to have to make the drainage pipe continually deeper as you move away from the house. 

    Draining to daylight is best, but it sounds like that's not an option for you due to a flat lot, so your going to have to install some type of drywell.  My first choice in your part of the world, where there is a lot of rain, is a real drywell like Piffin was explaining.  If your soil is sand and gravel, you might get away with a long run of perforated pipe (at least 20 ft, the longer the better) buried in crushed stone instead of the dry well, but forget about it if the soil has even a little silty or clay. 

    You can do a quick test for silt and clay - grab a handful or soil, add a little water to make it just a little wet.  Pack it tight in you hand and try to squeeze out a little ribbon between your thumb and first finger.  If it just breaks into granules, it's sand and gravel.  If you can get even a little ribbon of soil, you've got some silt or clay. 

     



    Edited 6/10/2006 8:01 pm ET by FlashGordon

  4. sungod | Jun 11, 2006 07:10am | #4

    Lets try to answer what I think you are asking.
    On a lot that graded is properly, the house would be on dirt that is 3 ft. higher than the street if its 150' away. I assume your lot is totally flat, so the top of your stemwall should be 18" above adjacent grade not just 6". If your stemwall is 3' high, then the dirt can be higher than adjacent grade to keep water from seeping under your house. I am guessing your have no basement.
    Here is a bit of "Magic" to "Pump" your raingutter water uphill to the street without an electric pump. Just run 3" ABS or PVC plumbing drain pipe with glue fittings and joints to the street/stormdrain/stream. At the house run with an elbow to extend the pipe a couple of feet higher than the other end. With the roof gutter going into this pipe, the water will go uphill. Disadvantage is that the pipe is always full of water, unless you have a "T" outlet that you can open and drain.

    1. Piffin | Jun 11, 2006 12:46pm | #5

      You are obviously in a land where it never freezes 

       

      Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

      1. sungod | Jun 11, 2006 06:35pm | #6

        Your right Piffin, I keep forgetting local conditions. I'm in Southern California where I don't worry about frostline, icedams, humidity, tornados, sunstroke and maneating mosquitos. We worry more about outrageous home prices, skin cancer and earthquakes.
        Back to the original question, maybe combining your idea of a "T" fitting at its lowest point to drain into a dry well. Forget dry wells if your on solid rock in Colorado, volcanic rock in Hawaii or clayey soil of Texas.
        I also thought raising the house 3' would be good so you don't have to worry about drainage. But 3' is not high enough for residents along the Mississippi. Also, some guys are on a tight budget and cannot afford a concrete / foundation bill that is twice as much.
        I do not mind you keeping me in check, cause I do a lot of things out of the norm. I learn a lot from others mistakes and mines :-)

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Up Next

Video Shorts

Featured Story

Fire-Resistant Landscaping and Home Design Details

These defensive details give homes a better chances of surviving wildfires.

Featured Video

A Modern California Home Wrapped in Rockwool Insulation for Energy Efficiency and Fire Resistance

The designer and builder of the 2018 Fine Homebuilding House detail why they chose mineral-wool batts and high-density boards for all of their insulation needs.

Related Stories

  • Old House Air-Sealing Basics
  • A Drip-Free, Through-Window Heat Pump
  • Insulation for Homes in the Wildland Urban Interface
  • An Impressive Air-to-Water Heat Pump

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Fine Homebuilding Magazine

  • Issue 332 - July 2025
    • Custom Built-ins With Job-Site Tools
    • Fight House Fires Through Design
    • Making the Move to Multifamily
  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Old House Journal – August 2025
    • Designing the Perfect Garden Gate
    • Old House Air-Sealing Basics
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data