Culverts (again but for a paved drive).

[EddieWalker]

rusts? not much.. as it's galvanized!..

I always wonder why people buy metal pipes, but until now, never really thougt about it other then it's just what they are used to and comfortable with. Here, in the land of red clay, they rust out fairly quickly. You can still buy them, but from what I'm told at the three places that I've bought them, the plastic culverts outsell the metal ones by a significant difference. The main reason that I'm told people buy metal is it's specified by the county, or it's what was already in there.

I never heard of any issues of the plastic pipe degrading. Is this something that you have seen personally? I have over a dozen of them in at my place and will buy another dozen in the next year or so. If they will degrade, then I need to address this and put concrete on the ends like you suggest.

Of the metal culverts that I've seen removed, rust is part of it, but so is blockage. They tend to hold material inside of them and over time, it just becomes easier to replace them then to try and clean them out. The plastic culverts are smooth on the inside and material doesn't seem to bind with the plastic like it does with the metal. Again, this is clay that I deal with and small amounts of gravel that we call iron ore.

Eddie

 

[rtimgray]

OK my driveway has everything mentioned not to do here done to it and I dont want to even talk about how much gravel is over it. Thank god my culvert pipe cannot read this thread it would fail on me immediately if it knew how badly it is installed

I'm gulity of a lot of that from what I read on this site. I know that what most folks say to do is a good practice, but in reality you can get by doing a lot less. We've even poured concrete on bare earth - didn't even put down a vapor barrier. Just scrape the grass and let it go.

Of course, it's only been there about 20 years, and had a couple of normal cracks. (this is for a barn floor). If anyone ever told it that it needs crushed, compacted stone and the grade should have been further excavated and that it needs rebar or welded wire and a vapor barrier, then we could be in big trouble. But I'm not gonna tell it.

And thank goodness nobody ever told my horses which side I'm supposed to approach from. I can't remember if you're never supposed to approach/mount 'em from the right or left - but evidently, none of the four of them can remember either, so we're mutually ignorant (i.e. blissful!).

Take care.

 

[Soundguy]

Soundguy, I think you are talking about polyvinyl chloride (PVC) plastic and not high density polyethylene (HDPE). The HDPE does not have the same UV degredation potential as the PVC. Plus if you paint PVC it helps with the degredation problem. Mowers are a bigger concern for the end of plastic pipes, but better the pipe than the mower.

I'm QUITE familiar with HDPE.. we install it all the time.. just about any plastic degrades to some extent with uv light.. some more than others.. sure hdpe holds up better than pvc.. but in the sun.. and after years.. plastic takes a hit vs coated metal..

soundguy

 

[Soundguy]

I am ov course, only speaking about florida, and my area.. can't speak for other areas. Keep in mind that homeowner / private road work is not the stuff we do.. we usually work for municipalities.. and as of yep.. I have really only seen metal or coated metal pipes with or without concrete miters and splash pads as culverts.. very rarely do we use plastic.. and on occasion.. we use hardi-pipe ( cemet-paper more or less.. ) and sometimes concrete pipe... both round and 'squash'.. etc.

soundguy

I always wonder why people buy metal pipes, but until now, never really thougt about it other then it's just what they are used to and comfortable with. Here, in the land of red clay, they rust out fairly quickly. You can still buy them, but from what I'm told at the three places that I've bought them, the plastic culverts outsell the metal ones by a significant difference. The main reason that I'm told people buy metal is it's specified by the county, or it's what was already in there.

I never heard of any issues of the plastic pipe degrading. Is this something that you have seen personally? I have over a dozen of them in at my place and will buy another dozen in the next year or so. If they will degrade, then I need to address this and put concrete on the ends like you suggest.

Of the metal culverts that I've seen removed, rust is part of it, but so is blockage. They tend to hold material inside of them and over time, it just becomes easier to replace them then to try and clean them out. The plastic culverts are smooth on the inside and material doesn't seem to bind with the plastic like it does with the metal. Again, this is clay that I deal with and small amounts of gravel that we call iron ore.

Eddie

 

[Aguanga]

Like soundguy, I also work for a general engineering contractor where we specialize in storm drain, sewer, water, and electric/communication conduit install. I'm not a fan of cmp for the same reasons eddie mentioned, but it does have some obvious functionality. Check with your local suppliers on pricing for cmp, hdpe, pvc (sdr35 sewer pipe), and rcp; then start making calls to local engineering contractors that install the stuff. You may be surprised to see how how cheap of a deal you can work out. Lots of good advice already given on install so I'll just add a couple of items to it... make sure you have good moisture on backfill. The most difficult area to compact is from bottom of pipe to springline (lower half of pipe) so if you're inexperienced or short on the right equipment, etc; I'd recommend a 1-2 sack concrete slurry for this region. A 12" pipe in 24" wide trench 30' long is just over a yard to accomplish this - cheap insurance. You'll get some better guidance with more info and or pictures - how deep are flowline of ditches relative to road height, how long, how much pitch or slope can you get in the line, how large of an area (watershed) will drain into and flow through the pipe, etc. I know Oregon can get a lot of rain at one time so it's better to go bigger within your budget. Remember that you have a highly compacted road, but if it's under standing water with the right soil conditions will pump and displace.

 

[atgreene]

A couple things to add here and clear-up. My expertise is in erosion management, road building and general excavation. It is also based in Maine where we get 4-5 feet of frost, so some of my info may not apply to your situation in warmer climates.

It sounds like you are simply draining a wet area on one side of the road to the lower side of the road. Not a stream bed or a common overtop situation?

A 12" smooth bore culvert is huge for most driveway applications. I'm all for overkill, but with proper plunge pools on both ends an 8" plastic smooth bore will handle vitually the same amount of water as a conventional 12" galvanized steel culvert.

You may be able to lay less material over the culvert than the diameter of the culvert, but it's not recomended for here. Maybe different elsewhere.

A vibratory plate compactor will do all the compaction you need for a driveway culvert if bedded in good quality 3/4" crushed gravel.

Galvanized culverts do rust out, but we have an excess of road salt to deal with here, so that may exacerbate the issue for us. I replace and install a lot of culverts, unless Maine DOT has anything to do with it, plastic goes in. Otherwise Maine DOT requires 15" aluminized steel minimum. What a waste.

Don't make this overly complicated, culverts are a pretty simple thing.

Good luck.

 

[gemini5362]

Like soundguy, I also work for a general engineering contractor where we specialize in storm drain, sewer, water, and electric/communication conduit install. I'm not a fan of cmp for the same reasons eddie mentioned, but it does have some obvious functionality. Check with your local suppliers on pricing for cmp, hdpe, pvc (sdr35 sewer pipe), and rcp; then start making calls to local engineering contractors that install the stuff. You may be surprised to see how how cheap of a deal you can work out. Lots of good advice already given on install so I'll just add a couple of items to it... make sure you have good moisture on backfill. The most difficult area to compact is from bottom of pipe to springline (lower half of pipe) so if you're inexperienced or short on the right equipment, etc; I'd recommend a 1-2 sack concrete slurry for this region. A 12" pipe in 24" wide trench 30' long is just over a yard to accomplish this - cheap insurance. You'll get some better guidance with more info and or pictures - how deep are flowline of ditches relative to road height, how long, how much pitch or slope can you get in the line, how large of an area (watershed) will drain into and flow through the pipe, etc. I know Oregon can get a lot of rain at one time so it's better to go bigger within your budget. Remember that you have a highly compacted road, but if it's under standing water with the right soil conditions will pump and displace.

Thank you very much for your post I now know that at least I did one thing right when I put in my culvert. You said to make sure you had good moisture on backfill. When I installed the new plastic ? culvert i rented a trackhoe and dug up the old one. I get the new one in place and it had started sprinkling. I decided that since all I was doing was covering it back up I could do that with my tractor and have two advantages. My tractor did not have a time meter measuring how much money I was going to owe when I got done and the tractor has a cab. I pulled the trackhoe up next to my tractor and got in the cab to start over to the culvert. it was about 2 or 3 minutes to the driveway where the culvert is. By the time I got there the rain had turned into a major heavens opening up gusher. It rained so much that I could not see out of my tractor windows with the wipers on high speed. I finally got the culvert covered so that it would not wash away. I am very very certain that I got enough moisture in the backfill of that culvert.