What is the lifespan of geotextile membranes?http:

[greentown]

I'm having a gravel driveway put down and have settled on having a Polystorm Soakaway heavy duty Crate system underneath:
http://www.plasticdrainage.co.uk/polysto....te.html

As per the instructions, the plastic crates will be sealed inside a Geotextile membrane:
http://www.plasticdrainage.co.uk/non-wov....ng.html

The gravel drive will be constructed in the usual way over the crates - so there will be
crate bedded in sand, wrapped in membrane then layers of sand - hardcore - sand - gravel - (I think that's the order).

Anyway, I just wondered, given that the plastic soakaway crates are full of holes, and the only barrier between the holes and void in the crates is the membrane - how long would it be before the system eventually fails and sand etc statrs to penetrate the membrane?

I've seen figures online of Geotextile lifespans of between 20 and 100 years - which is most accurate?

I think the contractor involved will use Terram - is this a good membrane?

All thoughts appreciated.

[lutonlagerlout]

terram is good
in practise the geotextiles should last a life time at least
we have never had any fail on us in the last 10 years of using them
LLL

[greentown]

Thanks - that's good to know.