Not about carpet but maybe some here know: Can you bury treated wood to border a gravel path? Is there any kind of coating that makes it last longer? What thickness is advisable? Any idea how long can the board last in the ground? We've looked at some plastic border products but the feedback (even for the real thick ones) is that you can't keep them straight and as time passes and exposure to sun, they conform to the pressure from the gravel. Thank you.