size of percolation pipe holes

cj maxx

hi im just extending/upgrading my raised percolation area as im getting a digger anyway in but forget how big to bore the holes in the drainage pipe. read here 8mm but that seems big from what i remember so 6mm or 4mm maybe, does anyone know? ,
also where to get terram or other geo textile covering in north east area and is it wild dear ?
heres the plan just so ye know
1000-1200 topsoil ( poor drainage on subsoil )
500mm wide x 550mm deep trenches of 20-30mm stone (300 below 150mm above the pipe) 1.5 m apart
pipe has a fall of 1/200
terram/geotextile stuff
topsoil
.thanx

muffler

8mm dia. holes. - see here - page 20 of the document.

cj maxx

sorry muffler i didnt get back earlier. thanks for the link .
a few more queries
how far apart are the holes? and should the pipe connecting the percolation drains together at the ends also be drilled ?
shoul each pipe be vented
once again thanks

rayjdav

Holes to be about 75mm centres, placed at 4, 6 and 8 o'clock on the pipe. Very common practice now to 'score' the pipe instead of perforate but get someone who has done it as can be tricky to get right.;)

Everything after the distribution box should be perforated, save for 90's and "T" joiners, and obviousl;y the vertical vent pipe:rolleyes:

Each run should be vented at the end of the run..

Supertech

You can buy the pipes pre drilled as well. Not sure of cost versus ordinary sewer pipe but not astronomical and saves on the time of doing it yourself.

cj maxx

pre drilled pipes are over twice the price in local hardware shop. :eek: soout with the cordless !
thanks for your answers guys (or dolls)

muffler

cjmc wrote: »

thanks for your answers guys (or dolls)

Aye, you wouldn't be sure what you get round here :pac: