Underdrains

[bank]

I specified that an 8" perforated pipe wrapped in filter fabric and backfilled with gravel (18" cover) be placed beneath a playground covered with wood chips. The architect wants to use styrofoam packing peanuts in lieu of gravel backfill. Does anyone have experience using this material for backfill around perforated pipes; i.e., will it work?

 

[Ron]

It will work, but it is compressible and unstable under load. If your trench fills with water, it will float and would likely displace or allow your pipe to drop down farther in the trench.

In my opinion, not a good idea.

 

[Hoagie]

I'm laughing my butt off. Styrofoam peanuts? Tell that architect to 'smoke another one.'

 

[MiketheEngineer]

Like many architects - he is nuts - peanuts

 

[civilman72]

Styrofoam packing peanuts?

Sounds like a good reusable/recycling idea - to make use of the Architect's extras from Xmas. Maybe he'll want to throw some bows and ribbons in there also?

Not trying to be obtuse, but I'd have to do a lot of research on prior use of this material as backfill before using it in my design.

 

[RWF7437]

Look out for Salmonella in those peanuts.

 

[BigH]

Bank - just one underdrain? Or are you providing the drains, say at 1.5 m spacing . . . 8 inches seems pretty big - but it depends, I guess on the layout. I probably would have considered 2 inch drains at 5 ft spacings.

 

[bank]

Thank everyoue for confirming my suspicions. Architects must take classes on how to yank our chains. I informed the architect that I would not seal any plans calling for packing peanuts. Instead, we will use 4" perforated pipe (thanks BigH), embedded in washed gravel wrapped in non-woven filter fabric.