A few of the Great Lakes Waterproofing Sales Guys have been quoting jobs where the homeowner has already tried to grade the yard so it slopes away from the foundation to help with water issues. Most of the time we encounter a layer of heavy duty plastic with rocks on top and a plastic barrier usually 4-6" tall, place around the perimeter.
It looks great but they wonder why there's still water in the basement. Before the Great Lakes Waterproofers start waterproofing, we have to clear away the rocks to help get our injection equipment in and we usually see the same thing. No prep work has been done on the ground before the plastic sheet and rocks have been laid down. Instead of tamping (compacting) the soil, the plastic is laid upon a somewhat graded area and rocks are laid on top.
The opposite effect has occurred.....the rocks compact the soil around the foundation causing a "funnel" situation, the water builds up on the plastic, is held in by the new barrier and is channeled back to the foundation, making the situation as bad or worse then before. Unfortunately grading away from the house requires a lot of work and professional equipment to be done right or the water issues will be worse. You're not alone if you try to waterproof this way, we see it all the time.
The Great Lakes Waterproofing Injection Method provides a foundation barrier against moisture and can fill in some of the low areas with bentonite clay, preventing water from pooling up in one area.