On perforated PVC pipe, which way do the holes go, up or down?
The holes go down, so as the water rises in the gravel it flows into the pipe and out.
Click here for more details in the ODOT book, 605.03 section B
Determining the proper cast iron grate size. [pdf document]
How do I install SmartDitch products? [pdf document]
How do I install a channel or trench drain? (video demo)
How to install a pop-up emitter and flo-well? (video demo)
How do I install an NDS Catch Basin? (video demo)
How to calculate flow rates for different pipe sizes. (pdf document)
How do you install a French Drain? (video demo)