Storm Water Overflow Pipe

Vermaraj

Engineer specd out a storm water retention system consisting of stormtech 740's and catch basins.

The 740s overflow down a hill into the wetlands. For the overflow he has specd 200' of 6" schedule 40 PVC. Are there any less costly options for this overflow pipe?

Trying to educate myself before talking to him again. Not a bad guy design wise. But clearly designs from a money is no object perspective.

tgeb

What do you think would be an appropriate alternative?

You're not going to change the engineer's mind.

I just priced out some 6" sch40 for downspout drains on a home remodel.

200' of 6" would be $456.00 before taxes and delivery and does not include any fittings. 200' of 4" would be $210.00. An increased cost of $246.

Of course the cost of installation (of the 6"), is a little bit more, but what are you thinking this can be installed for?

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Tom

www.gebcon.com

rino1494

I have dealt with many engineers and none of them view cost as an option. If an engineer spec'ed it that way, then that is the way he wants it. The only other thing you could do, is price out 6" sdr35. It might be cheaper, but not by much.

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dayexco

we're not engineers put in what he wants....hear the expression..."ours is not to reason why, ours is just to do or die"? he spec'd it, install it...what's 2-300 bucks in the scope of the project?

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someday, i'll be as patient as Nick.

Vermaraj

It's been my experience that when you ask the question, "would xyz pipe work as well". And the engineer gives you a dumbfounded look then it would work just fine.

I was able to cut the price of the septic system for this job in half just by leafing through the standards and asking why he chose system x versus system y. His answer was, "I never heard of that system let me check it out."

So we both learned something and the client was better off for it. In the end I will make more off the sch40. I just mark up the subs work and charge the client accordingly. These days every dollar counts and these clients aren't exactly swimming in money.

dayexco

if you're using a cellular core schedule 40 pipe, you're using a product that has no where near the structural wall integrity the class 200 pvc water main has. it also has the same O.D. of schedule 40 pipe. cellular core pipe has been known to crush during backfilling operations. it's intended use is shallow bury under a house floor, or within a wall. you were wise in private to suggest some value engineering mods...nobody is against saving money. personally? i don't want to save $50 to have it cost me $3k later on.

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someday, i'll be as patient as Nick.

PipeGuy

Who would benefit from saving the $300 difference between using Type S HDPE pipe or SDR-35 pvc instead of SCh 40 PVC? The Owner? You? Frankly, if I'm the design engineer I might be inclined to charge the Owner something for my time to review and approve an alternative product. Afterall, from the engineer's viewpoint he's already properly designed a system and set his seal upon it.
Design professionals except legal liability for the performance of the systems they design. As contractors we don't always have an appropriate perspective from which to consider all the facets the design professionals have had to consider in the development of any given system. In this case there may be any number of reasons for which the relatively heavy PVC pipe is specified and not some other PVC or HDPE product. It it were me, I wouldn't even consider asking the engineer to consider an alternative for 10 pieces of $45 pipe.

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Upchuck

I usually only suggest alternatives to engineer when there is a big cost savings that doesn't impact job specs. On a septic I recently did the engineer speced out 96 (8 rows of 12) small infiltrators to keep height of leachfield down. I suggested an infiltrator that was only 4" taller which I felt wouldn't affect much since it was a raised system. We used 45 infiltrators instead amd saved the HO over $1200.

I know that the HO gave me the job because I was able to save them money. I still felt like the system was over designed compared to usual systems we install but I wouldn't say that to HO or designer because that not part of my job. Also some engineers don't like to be questions by contractors.


In your case I would use Sch 40 pipe. The cost difference isn't that much.