Im in the process of laying artificial grass in my garden,im laying weed membrane,layer of type 1 , a layer of sharp sand than my grass, ive got 5 big bulk bags of type 1 and sharp sand, i was thinking of using the empty sand bags on top of the weed menbrane as extra protection,does anyone think it will be a silly idea to cut them flat, its strong material and water passes through it eadily enough. Dont really trust just weed membrane.