# Drain Pipe



## denick

Many people in this area are now using SDR 35 pipe for footing drains and other drains of 8' or less in depth. They say that PVC pipe like a Hancor Smooth wall drain pipe can't stand up to the use. There are many drains being dug up with pipe deformed and almost closed off.

My feeling is the reason for the problem is incorrect installation. The PVC pipe needs to be backfilled with correct compaction on the sides of the pipe so that the pressure exerted by the weight of the backfill is resisted on the bottom and sides equally.

That said is it possible in most uses to do that correctly. Or does the time taken negate the cost of the more expensive pipe?

What are your thoughts?


Nick


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## jmic

I use Hancor Perf. for footing drains and use plenty of stone to protect the installation. I do use SDR35 for run offs and all uprights for leader pipes. If leader drains are close to surface I'll use SDR 35 also. Otherwise I use the hancor perf. around footings and hancor sol. on top of footings for the leaders.


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## dayexco

i agree denick, hancor should work if installed properly. a pipe's strength is in the lower quadrants of the pipe. if the material is compacted properly under the haunches of the pipe at that depth, it should never collapse.


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## tgeb

I use the corrugated perf for around the foundation. Drains to daylight, I started using schedule 40 PVC. 
Same with down spout drains, sch 40, I explain to my customers that sch. 40 is much less likely to get crushed and they are happy to pay the increased cost.

I just jetted some corrugated downspout drains last week that were clogged with debris. Drains ran under a flagstone on concrete patio, moisture problem in basement.

We fixed it.


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## jmic

Tgeb,
Nothing personal but I'd never use corrugated drain pipe, you're taking about that stuff in the rolls? Well I guess you can get it in 10 footers as well.:no: You go from that stuff to sched. 40? Pretty extream.


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## denick

When talking about any small size plastic pipe how accurate can any thing be? The rolls of corrugated pipe have a tendency to undulate. And the same even pressure backfill problems are present as with PVC drain pipe. But almost every 4" pipe I buy has a bow to it and how do you know how that pipe will settle? Can small diameter drain work be done accurately, really accurately? Does it matter? 

Nick


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## tgeb

> you're taking about that stuff in the rolls?


Yes, the stuff in the rolls, we use it for drain tile bedded in stone, never for out falls.

I used to do the outfalls with sdr35 but found that it was easily crushed or at least cracked. Then decided it was best to use the sch40.

Well actually 20 years ago we did the outfalls with the solid version of the same corrugated pipe. It is still allowed by code here, but I won't use it.

BTW No offense taken. 



> You go from that stuff to sched. 40? Pretty extream.


That didn't happen overnight.

And since we are talking about different products, what is this Hancor you guys are speaking of? I'm always ready to provide a better product.


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## jmic

tgeb,:thumbsup: Hancor Smoothwall

Smoothwall pipe, is available in 10' (3m) lengths; 3", 4" and 6" (75, 100 and 150mm) diameters, and joins with simple, secure bell-and-spigot connections. The pipe is made with a white, high density polyethylene layer around a black polyethylene core to form a lightweight pipe with excellent beam stiffness.

Meeting ASTM F810, ASTM D1248 Type III and ASTM D3350, Smoothwall is very popular for sanitary leach field use because of its low cost, large perforations, and high beam strength when compared to single-wall perforated polyethylene pipe. Beam strength is a measure of the stiffness of a pipe in the longitudinal direction. Because Smoothwall is relatively stiff in the longitudinal direction, it can easily be laid straight and "true to line and grade". Smoothwall pipe requires a stone backfill envelope to allow it to function effectively for leach field applications.

The pipe provides for safe, easy, efficient installations without breaking, splitting or cracking, and is more impact-resistant that PVC, ABS or styrene.

Like all other polyethylene products, Smoothwall will not corrode, is unaffected by fertilizer and herbicidal chemicals, is impact resistant and can be installed in subzero temperatures. Smoothwall can be used for all your turf drainage needs as well as sidewalk culverts and on-site waste management systems.

Diameters:


3" (75mm); 4" (100mm) and 6" (150mm)

Length:


10' (3m)

Specifications:


ASTM F810

Joining System:


Bell-and-spigot

brochure


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## rino1494

Around the footers, we use a triple wall S & D pipe and SDR35 for the drain out to daylight.


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## jmic

Hey Rhino,
Can you give a little more info on that Triple Wall S&D Pipe.:blink:


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## PipeGuy

I see all kinds of stuff spec'd - often with no obvious rhyme or reason. 

Crushed pipe is usually a function of insufficient cover (protection from traffic loads) or uncontrolled backfill. Controlling backfill in the bottom 1/3 of the pipe accounts for a huge proportion of the pipes ability to support loads and assuring that rubble has adequate seperation from the pipe itself is another big deal.
Personally. my concerns about HDPE drain tile pipe is when its used in shallow applications, when it's used in situations where backfill is uncontrolled (read 'around home foundations) and where it's exposed to daylight. I'd say once you're burying something less than 2 or 3 feet deep you should use SCH 40 for the additional strength and resistance to being eaten (I've seen squirrels tear up some drain tile)


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## rino1494

jmic said:


> Hey Rhino,
> Can you give a little more info on that Triple Wall S&D Pipe.:blink:



Sure thing good buddy :thumbsup: 

http://www.baughmantile.com/triplewall.htm

It comes with a coupler already installed on it.


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## denick

Fact?
The circle being a very strong object can resist a great amount of pressure on the inside or outside when the pressure exerted is equal on the same surface side of the circle.

Question,
In most installation of small diameter PVC drain pipe the bottom 25% of the pipe is supported solidly. The top third of the pipe is bearing the downward weight of the backfill. Can the 42% left that are the two side surfaces can the material in contact with it be compacted sufficiently to prevent failure?

Nick


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## PipeGuy

Ultimately, anything will fail if subjected to loads greater than its inherent strength characteristics unless such load can be transferred to something else - like if you backfilled thinwall pvc entirely in concrete. Typically in the case of pipe failures you're dealing with stresses from point loads like vehicle tire loading, backfill debris that makes contact contact with the pipe, and shear forces developed by inconsistennt bedding.
I'm not sure I understand the question but I think the answer is yes - depending on the pipe's strength characteristics it can be backfilled sufficiently well so as to induce failure at the top or bottom before failure occurs at the 'remaining 42%. With concrete pipe for instance, doing such doesn't take much effort.


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## atulc

*Footing drain recommendation for 10' below grade?*

What drainage pipe do you recommend for footing drains where the pipe would sit under 10 feet of soil? A section of the pipe would be under a stone patio. Following this thread, I see that Denick recommends SDR35 perforated pipe for upto 8' depth. Several others recommend triple-wall perforated pipe. Which pipe can best withstand 10' deep soil?


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## fhdesign

We have switched to using sdr35 solid and perf and are having good success with it, we just use white pipe for where the leader drains are exposed.


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## atulc

Fhdesign - thanks. I want to make sure we are talking about the same thing. I am looking for footing drain pipe recommendation. You mentioned leader drains which normally run about 3' below grade. Have you used SDR35 for footing drains 8-10' below grade? Do you use the pipes with gasketed end or bell end? 

Anyone has experience with triple-wall perforated pipe at that depth? How well do they hold up over time? Any pros or cons vs. SDR35?


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## fhdesign

Yes we use sdr35 for footing drains, non-gasketed or bell end, but any good perforated pipe installed correctly will work fine. However you may want to use solid sdr for the footing drain runoff.


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## Gnella

Around here certain towns require sch. 40 down spout connections. Connections to spout have to be 4 inch and main trunk MUST be 6 inch all sch. 40. In one town in particular you have to use sch. 80 under the driveway . We have used the smooth wall and have found it very successful as well. As stated earlier I think it comes down to bedding:thumbsup:.


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