Right now, I have it on my wooden deck, I haven't had a chance to use it yet. Is it ok to use it on the deck? What are the odds ash or coals are going to fall and start a fire? Or should I store it under my deck, and roll it out onto the grass and use it? Is it any safer, as long as the grass isn't really dry? There's nowhere else where I can use it. I should have thought about this before I bought it, but I'm sure theres a way to make this work! Thanks!