downspout extension underground


  #1  
Old 03-19-03, 05:46 PM
stooge
Visiting Guest
Posts: n/a
downspout extension underground

Not sure this is the right forum, but here goes. I'd like to extend my leader downspouts away from the house. Can someone recommend a method. I guess I'd take an 8' foot section of perforated PVC pipe with an elbow, dig a trench, embed in stone and backfill. Does this sound right?

Do I cap the end of the pipe or leave open? What size stone, how much above and below pipe? Is pitch critical or OK as long as it is pitched? Trench depth?, etc. What other details am I missing? Thanks.
 
  #2  
Old 03-19-03, 07:45 PM
L
Member
Join Date: Mar 2000
Location: Arlington, WA
Posts: 8,670
Upvotes: 0
Received 1 Upvote on 1 Post
I think you are on the right track, but I will make a couple of suggestions.

First, make the first 4 or 5 feet of pipe solid, not perforated. Make the last 4 or 5 feet perforated. Put about 12" of rock below the perforated section. And don't put a cap on the end. Think you'll have it.
 
  #3  
Old 03-20-03, 04:48 AM
njhotrod
Visiting Guest
Posts: n/a
Is this ideal?

Wouldn't the water need an outlet or a vessel (dry well) to prevent it from puddling, backing up in the downspout, or flowing back towards the house?

I ask this question because I have some sort of underground downspout drainage system installed in my house. Although they seem to take any water that I run through them, I don't have a clue where the water is going. I am fighting a slight moisture problem in my basement and wonder if the downspout piping might be contributing. I would abandon the underground system, but there is a lot of concrete walk and patio around my house and to have downspout extensions across the concrete would be inconvenient.

Short of digging the system up, any suggestions for finding the outlet of these downspouts?

Thanks,
Joe
 
  #4  
Old 03-20-03, 04:13 PM
stooge
Visiting Guest
Posts: n/a
Thanks lefty, sounds like a plan.
 
  #5  
Old 03-20-03, 04:40 PM
magister
Visiting Guest
Posts: n/a
Hotrod; Basically the designed discussed is sort of a variation of a dry well; The water escapes from the pipe via the holes; A similar system is often employed behind septic tanks (or at least it was the last time I helped put in septic tanks, 20+ years ago)

If your piping/dry well is taking the run-off, I wouldn't rush to dig-up the piping; Though, that would be the only way to find it, if the plastic pipe ends underground and it's not marked on any documents. Instead, you might want to do a search on this and the basement forum in an effort to better diagnose your actual problem.

As for digging a new dry well, you could run the pipes under the walks with very little effort and if that is what you decide to do; Though, once again, I don't know that I'd rush to replace your system, if it is functioning; Post back and someone would probably give you more details as to how you should procede...

Hope I Helped;
R
 
  #6  
Old 03-20-03, 06:11 PM
L
Member
Join Date: Mar 2000
Location: Arlington, WA
Posts: 8,670
Upvotes: 0
Received 1 Upvote on 1 Post
Njhotrod, I'm only guessing here -- I can't see your system. The downspout drainage system at your house probably has solid pipe (ADS) connected at each of the downspouts that runs past the concrete. From there, it either goes into a perforated ADS that the water dissapates through, or it may be a solid line all the way through the yard that dumps into a rain gutter or storm drain. If you can't find an outlet, I would guess that whoever installed the line used the perforated pipe to disperse the water. I would hope that they installed the system to take the run off past the concrete (solid ADS), before they put it into a perforated ADS, IF, in fact, that is what they did.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: