Culvert options?

KubotaSteve · Jan 5, 2005

I bought a 20 ft section of pipe like Bill is talking about from Lowes. I bought the 12" diameter for around $100 and I think the 15" diameter is $125. I got mine from Lowes. It is pretty strong. I have mine under the driveway with about a foot of fill on top of it and have had a dumptruck with 18 ton of stone go accross it. Remember the bigger the pipe you go with, the easier it will be to clean if necessary and the less fill you will need.

bczoom · Jan 5, 2005

( I have an area behind my garage that is used for water run off. The ground slopes down away from the garage and runoff from the road and my driveway run through this area as well. There is no water in it unless we have a downpour and then it isn’t much. I would like to fill this area in to build a wood shed that will attach to the back of my garage. I also want to place an outdoor wood furnace on this filled area. )

David,

Sorry, but I'm not getting a clear mental picture.

When you say "run off", do you need this culvert to catch the water over the distance of the pipe (all 30') or do you just need to catch the water at the end of the pipe and use the culvert to route it out of your way?

If the former, the french drain is probably your best bet. Get stone all the way around the pipe but don't cover with dirt. Once the dirt packs, no surface water will reach the pipe. For the wood shed and outdoor stove area, you could switch to non-perforated pipe and cover with dirt but just make sure any water running towards these 2 things has been accounted for (re-routed).

If the latter, I'd go with 12" like Bill pictured. One thing I've found about using 4" flex is that debris (leaves and such) can clog it pretty easily /forums/images/graemlins/mad.gif. If you go this way, you may want to get something for the intake end to keep it out.

MMM · Jan 5, 2005

One big one is worth a lot of little ones. Here's a very informative thread on drainage pipes.

drainage thread

dlabrie · Jan 6, 2005

( When you say "run off", do you need this culvert to catch the water over the distance of the pipe (all 30') or do you just need to catch the water at the end of the pipe and use the culvert to route it out of your way?
) 

I need to catch the water at one end and route it out of the way. We don't have a TSC in NH /forums/images/graemlins/frown.gif I will be going by HD next Tuesday.(it's 40 miles away) I will stop and see if they have the 12 or 15" pipe that Henro posted.

I should have taken a picture to post. There is a big snow storm headed this way, so I probably won't get a chance.

Currmudgeon · Jan 6, 2005

When picking up surface runoff, it is important to have sufficient capacity in your storm sewer or culvert to carry the expected amount of water. It's also a good idea to grade the site so the unexpected amount of water will flow around your expensive stuff, rather than trough it. If you can't grade in an overland overflow path, it's customary to design the culvert to carry the 100 year flood. In a situation I'm working on right now, even that may not be adequate.

Putting in a big pipe is cheaper than cleaning up the damage. Doing the grading to carry the excess water on the surface can save a lot of pipe.

How much land drains to the inlet of your culvert? That's the key to suzing the pipe.

LBrown59 · Jan 26, 2005

They have brochures with the stuff listing all the attachments you can add to it. There is also a 6" roll thetas 100 ft long, but the price is over $100 for it.
EddieWalker
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You can do a double run of the 4'' for less than the cost of a single run of the 6''.
A double run 4' will carry more water than the single run 6'' also.

Around here you can't get the fittings needed for the 6'' like you can buy for the 4''.

Egon · Jan 26, 2005

( A double run 4' will carry more water than the single run 6'' also.
)

The one 6 in. has a larger area than two four in. pipes. Friction would also be less for the one 6 in. pipe.

I like the idea of the large [ Henro's type ] pipe. A thunderstorm can drop a lot of water in very little time.

Egon /forums/images/graemlins/grin.gif

LBrown59 · Jan 26, 2005

( Yes that is right. Can you buy 12" flex pipe at HD? I can't find much on their web site. 

I don't know...the pipe I was referring to is rigid, double wall, and sold in 20' lenghts (they will sell a half length though). I got it from a local culvert pipe supplier. Even 18" by 20 feet can be moved around by one person, so it is not that heavy. It has a rubber gasket on the male end, that goes inside at the bell end, where pipe sections are joined by sliding one inside the other...not too bad to work with.

I think I have seen larger diameter (12" or larger) flex type corregated piping sold in 20' lenghts at TSC. This stuff is not double wall though, and is more like the 4" stuff that Home Depot sells, just larger...

I've attached a picture of the stuff I used... )
======
1* It has a rubber gasket on the male end, that goes inside at the bell end, where pipe sections are joined by sliding one inside the other...

*********
If joining 2 or more sections of this stuff together make sure they are all from the same manufacturer.

Different Manufactures aren't compatible with one another and the sections won't connect to each other.

Been there done that paid the consequences! LOL

LBrown59 · Jan 26, 2005

( ( A double run 4' will carry more water than the single run 6'' also.
)

The one 6 in. has a larger area than two four in. pipes. Friction would also be less for the one 6 in. pipe.

I like the idea of the large [ Henro's type ] pipe. A thunderstorm can drop a lot of water in very little time.

Egon /forums/images/graemlins/grin.gif )

What is the area of a?
1* 4'' circle
2* 6'' circle
3* 2 4'' circles.

What is the volume of each of these 10 inches deep.

How many gallons of water will each one hold?

Chuck52 · Jan 26, 2005

Area of circle = Pi*(radius)**2. Four inch diameter = 2 inch radius, area = 3.14*2*2 = 12.56 square inches. Six inch diameter = 3 inch radius, area = 3.14*3*3 = 28.26 square inches. Therefor one six inch pipe will carry more volume than two four inch pipes, and the flow resistance for the six inch pipe will also be less.

Chuck