What builders plastic should I use for a 40cm deep retaining wall: medium or high impact?

[isidore12]

I am planning to build a small retaining wall, using besser block and mortar, about 40 cm deep, in-ground.

I have to choose between high or medium impact builder film.

Obviously, high impact builder film would be the best choice, but it is also 150% more expensive.

I would please like to know if the benefits (i.e. durability and longevity) justify the difference in price.

Thank you

High impact builder film:

https://www.bunnings.com.au/cagroup-4-x-50m-x-200um-orange-high-impact-polypro-builders-film_p036088...

$255

Medium impact builder film

https://www.bunnings.com.au/cagroup-4m-x-50m-x-200um-black-builders-film-polypro-polyethylene-film_p...

$118.56

[MitchellMc]

Welcome to the Bunnings Workshop community @isidore12. It's wonderful to have you join us, and many thanks for your question about Builder's film.

For the purposes of your application and project, the CAgroup 4m x 50m x 200UM Black Builders Film Polypro Polyethylene Film will be fine. You've already selected the thicker 200UM version, and once it is in place, it's not going to receive any more impacts. If this were sheeting that would be walked over for several months with stones embedded in the bottom of shoes, then the high-impact version would be warranted. I'd go with the more budget-friendly option.
 
Please let me know if you have any questions.

Mitchell