Your auto store should have a piece of sheet metal fabricated to use on garage floors, to catch leaks from vehicles. It costs about 8 bucks or so, depending on the size you get. You can even paint it to match the deck. I've been using one and it does catch grease and dropped food.

Both suggestions sound good to me, in hardware/outdoor stores I've also seen mats for sale that are designed to sit under the bbq.

The sandbox is an intriguing idea, probably the most fire-resistant, and you can replace the sand if it becomes greasy.

Is it a gas grill? If so, the gas tanks should be kept 5 ft from the house and 10 ft from wall openings.

Thanks Handymac. The sandbox sounds like a great idea. I could make it like a beach. I like the idea that I could easily change out the sand every year or two. Not too much cost, very fire resistant, grease absorbent, but, we have a lot of cats in our neighborhood and I don't know if they would decide it was their sandbox.

Good point mightyanvil. Fortunately where I will put it is about 30 feet from the nearest wall. I have 3 units - a gas grill, a charcoal grill, and a charcoal smoker (Weber Smoky Mountain.)

Yeah, the cats do pose a potential adventure possibility. :-)

Maybe a cover for the sandbox?

other than dropping small utensils thru it, there is no need for prtoection from teh heat. teh heat travels UP. look at the spot in teh yard where you cook, the grass does not brown so not much heat getting down low.

you may get drip stains though, my grills all drip a good bit of "juice" when in use.

anyway, i have never seen anythign special done to protect the deck. you can if you wish, it just is not necessary.

I understand that heat rises, but the smoker is fairly close to the ground and it does get warm underneath it. So heat is a concern. I am also concerned about any errant burning charcoal that may fall down. My concern was heightened the other day when a neighborhood house burned down from a cookout on a deck two days before. That has made me more cautious about heat, fire, and grease.

then yes, a metal pan under it would be the best thing. a sheet of plywood or something is still wood.

You are right to be cautious, gas bbqs are not quite so bad (seen a lot of melted siding though) but charcoal is another matter, you need something there and it should always be supervised. Sounds like a nice setup. Apart from the other benefits of sand, it's insulating to some extent and would tend to extinguish embers.

There are treatments to make it less appealing to cats, otherwise I suppose you could have some sort of cover over it, even an old folded tarp.

According to the Fire Marshall in my state the greatest risk from a gas grill is a broken or malfunctioning gas to tank connection. If gas escapes it is heavier than air and therefore is very dangerous on decks above the first floor. In fact it is illegal to have one in that location in this state. Most of the home fires here were caused by the gas leaking and finding an ignition source below.

There are a lot of mats made to protect wood decks from gas grills but most are not fire-resistant enough for synthetic decking or charcoal grills so metal is probably the best option.

Here is a link that might be useful: metal grill mat

Thanks Mighty for the metal grill mat link. Those are nice. I currently am using a drip pan I picked up at the auto parts store under the Smoker to catch any grease. These pans are nicer and larger. But, I think I will try to work with the sand box. I just have to figure out how to cover it. I need to come up with something economical and easy to take off, but will stay put in wind or rain. Any suggestions?

If I were going to that much trouble, I would use something more stable and attractive like stone dust or pea gravel perhaps with a filter fabric and an open mesh below it for drainage.

I have my grill on a large deck. Cooking some steaks a few years ago, they caught fire and the flames were shooting out of the grill and around the deck railing. I was sure the deck would burn down along with the house. I ran inside looking for baking soda, couldn't find any but threw a canister of flour all over the grill and deck. Put the fire out, but I think I was just lucky.

The whole railing was black from the smoke, but did not burn. It was treated lumber.

"...threw a canister of flour all over the grill and deck. Put the fire out, but I think I was just lucky."

Very lucky.
Flour dispersed in air is flammable and explosive.

You were indeed lucky. Salt would have been a better choice in the absence of baking powder. Maybe even sugar!

A good reason to keep a fire extinguisher handy if you have a bbq.

Jane, that is one of the situations I want to avoid. Having a fire extinguisher nearby is an excellent plan.

Mightyanvil, I am interested in your suggestion of something more stable than sand. Does stone dust or desiccated granite pack down so much that it would be hard to remove if I needed to change it out? What about walking on it barefoot? The area is near a pool and I know pea gravel would be hard on the feet, but what about stone dust or desiccated granite?

Sugar is flammable lol. Don't use it for fire!

I have been using a 3x5' piece of 1/4" hardi board under the grill for a couple years now and it works fine. We have a kennel run filled with straw under the deck so it was a BIG issue with us. keeps the grease off too!

tcmat....Be careful of putting down a plastic mat to protect your deck from grease splatters. I bought a cheep plastic mat and put it down on my Azek deck to stop the grease splatter from staining the boards. When I removed the mat, I was left with a gray "stain" from the mat out gassing into the Azek material. It took me 3 days to get that that chemical "stain" out with hit and miss solutions which, I'm sure took the top finish off the Azek boards.

We have a smoker on one wood deck and a grill on another. Both pressure treated wood. The smoker is a pellet smoker. It has a drip pail on the side. We do live up next to wilderness, and one time I forgot to empty the drip pail on the smoker, and some critter got to it, so there was some grease spilled, but it disappeared in time. The grill is propane and is hooked directly into the propane tank line that supplies heat for us. We have never had any problems with that at all. Our decks are not stained or painted. Just au natural.

rorobona, hopefully he was careful as he last posted about this six years ago........

I guess I was careful because so far I have not had a problem. I bought a metal pan that is designed to go under cars to catch drips and put that under the smoker and a mat at Home Depot to put under the gas grill. They both have worked well. Thanks for sharing your experiences