Culvert Question

[justinramani]

Hello Everyone!

The wife and I are getting ready to have a culvert installed across a creek on our property. We originally were looking at double wall HDPE plastic, but a guy we know out here happens to have two sections of 36" x 8' concrete culverts that he is willing to sell to us for about $140. The culverts look to be in great condition. The two together will give us about a 16' crossing.

The HDPE (plastic) pipe would have been one piece and 20' long, but would be significantly more expensive. We have a guy that can load and transport the concrete culverts to our property for a very reasonable price.

What do y'all think? Go with the concrete, or opt for the HDPE?

Thanks in advance

Justin
Fayetteville, NC

 

[dodge man]

Thats pretty cheap, I'd go for the concrete.

 

[LD1]

Only 16' of concrete culverts isnt gonna leave you a 16' opening. At least not unless you pour concrete around the ends or come up with some other kind of retaining wall. With ~2' or so of dirt on top of the culverts, you are gonna loose about 3' each side from the bottom of the culvert to the flat of the crossing. So your actual crossing will me more like 10' wide. If just for tractors, ATV's or foot traffic that is probably fine. But for full sized vehicles, that wont seem very wide of a crossing.

And are you sure 36" is large enough? Any pics of the area?

 

[justinramani]

LD1,

You think we will really lose out on 3' each side? I figured we may lose some space, but I didn't think we would sacrifice 6' across a 16' length. I don't have any pics of the area right now, but I can probably get some later today or tomorrow. I see a lot of driveway culverts that cover almost 100% of the length of the pipe. Those culverts don't look like they lose out on any width. I am far from an expert on these things - so your advice is greatly appreciated.

 

[ovrszd]

I share LD1's concerns about the width. But then, we haven't saw the site nor heard how deep you are burying the culvert??

My next concern would be setting the concrete culvert. What's your plan for that?? I have no idea what 8' of 36" concrete culvert would weigh?? Lastly, you'll have to create a very solid platform to lay it on to keep it joined and filling the hole will be critical.

The plastic is wayyyyyyyyy easier to deal with. And the cost will seem irrelevant next year.

Only down side to the plastic is burning. Again, not sure of the surroundings but if it's grassland that you frequently burn you'll hafta babysit around the ends while burning so you don't get it on fire. Otherwise it's extremely durable and you'll never have to mess with it again.

 

[ovrszd]

LD1,

You think we will really lose out on 3' each side? I figured we may lose some space, but I didn't think we would sacrifice 6' across a 16' length. I don't have any pics of the area right now, but I can probably get some later today or tomorrow. I see a lot of driveway culverts that cover almost 100% of the length of the pipe. Those culverts don't look like they lose out on any width. I am far from an expert on these things - so your advice is greatly appreciated.

At a glance you should have a pretty good idea how much fill you'll have over the culvert?? So what's your guess??

 

[justinramani]

We are thinking about 1 foot of fill on top of the culvert..... I will snap a picture and post it up in a few minutes so that you can better see the area.

- Justin

 

[LD1]

3' loss os over 5' height, assuming its 2' burried. Thats slightly steeper than about a 60 degree angle. It could easily be more than that with erosion. Depends on what the fill is.

I agree, go plastic. ITs longer to start with. And you can handle it easy. With the cost of moving and setting, plastic will probably be cheaper in the long run.

 

[greenmojo]

+1 to the shoulder comments.

The price for the concrete culvert is great, but it may just be a little short depending on your needs.

A 20' culvert sounds great, then by the time you get your surface on and shoulders cut in, you can't get 2 rigs driving side-by-side any more. Starting at 16', you're already in the hole.

~Moses

 

[ovrszd]

We are thinking about 1 foot of fill on top of the culvert..... I will snap a picture and post it up in a few minutes so that you can better see the area.

- Justin

That helps. But understand LD1's point. You can't get the dirt fill to stand vertically. So with that 1' of fill over the top of a 3' culvert you now have 4' of fill to hold in place. Being a total optimist you are going to lose 3' on each end. Now you have a 10' drive.

 

[justinramani]

Here are pictures as promised. there is a elevation change on both sides of the creek. You might not be able to tell in the pictures, but the water goes sub-surface for 8-10 feet before it re-emerges on the surface.

 

[justinramani]

ovrszd,

Tracking now! That makes sense. I may be able to get a third section of concrete culvert. That would get us a starting width of 24'. The transportation/movement of the concrete culverts isn't an issue. We have a guy that will load them, move them, and unload them at the install site for just over $100.

 

[ovrszd]

Understand, pictures are very hard to get a clear picture when the entire surroundings are not known. With that said, I don't see anyplace to bury a 36" culvert? Are you planning to haul in dirt and elevate the roadbed? I only see a minor indention in the ground that might be a foot deep? I'm surely not getting the whole picture. :confused3:

 

[ovrszd]

ovrszd,

Tracking now! That makes sense. I may be able to get a third section of concrete culvert. That would get us a starting width of 24'. The transportation/movement of the concrete culverts isn't an issue. We have a guy that will load them, move them, and unload them at the install site for just over $100.

Then you have to put them in the hole. Will your tractor handle that job?? Maybe you are planning to hire a backhoe??

 

[justinramani]

Thats correct, we are going to pull fill dirt from another part of the property and raise the elevation to accommodate the culvert/access road.

 

[justinramani]

We are doing some clearing and will have the machines on site to place the culverts.

 

[greenmojo]

ovrszd,

Tracking now! That makes sense. I may be able to get a third section of concrete culvert. That would get us a starting width of 24'. The transportation/movement of the concrete culverts isn't an issue. We have a guy that will load them, move them, and unload them at the install site for just over $100.

A third section of that concrete culvert would seal the deal for me. A 36" culvert would be nice. I'd like to see the after pictures too, will work out well.

~Moses

 

[LD1]

Not sure how much your total cost will be with the concrete, delivery, etc. Plastic culvert would be ~$800.

Have you considered a pair of 24" culverts instead of the 36? Flows about the same, but a foot shallower means a lot less filling

 

[greenmojo]

4 36" M/T tires might come in around $800 and you could just drive through the creek! ;-)

 

[justinramani]

LD1,

I didn't think about doing two smaller culverts. That may work out for us also. I thought I was set, but I guess I may have some decisions to make yet. Does concrete need to have a lot of fill on top to support heavy loads - or is the concrete itself enough to support heavy loads?

Also - do you think I could build side walls out of cinderblock on both sides? That may allow me to keep the fill on top of the culvert and avoid losing too much width.

Thoughts?

Thanks to everyone for their input.

- Justin