Try it out on a wooden picnic table and find out how much heat it throws downward.
You can get a baking stone and place it on that, or get a large cookie sheet. As you said treated lumber like a picnic table is probably the est.
PyroProtecto-Fireproof-Grill-Charcoal-Grills-protects-flooring
They make clamp on arms for using Kuuma grills on boats, do you have a deck railing? I can’t honestly see that one sort of grill would throw more heat downward than another, I’ve grilled on a cast iron hibachi that was set right on a wooden deck rail with no scorching and the hot cast iron was mere inches from the railing, but if it’s a concern get a metal table or clamp on arm.
It says you can cook anywhere, so it’s OK whatever you use:)
Maybe use your camp kitchen and put a couple of 1 x 10s under the grill to protect the surface.
Just then, two fire trucks roared by, sirens blaring, lights flashing. They stopped at a house right down the block.
All twelve of us raced out of the back yard, down the street, where we found the owners of the blazing house standing by helplessly.
They glared at us with looks of disgust.
Suddenly, we realized why………we were all still holding our roasting forks with marshmallows on them…
On a more serious note, most solid surfaces will be fine, as most of the heat will be directed upward. Just make sure you aren't setting your awning on fire... :)
Check with a hearth/woodstove outlet. They’ll have a range of mats and heat shields you can modify to whatever size you require. Or fabricate wood to fit your ideal design and adhese aluminum foil to it with stovepipe cement.
Get a circle or square, big enough to set the legs on, of plywood at least 3/8” thick. You can fasten the feet to the slab of plywood if you wish, to make it more stable. Building supply stores sometimes have them avail able pre-cut, as table tops.
One word: Durock. Explanation: cement board normally used for vertical installs of tile, etc., especially in wet environments like showers. It is also heat-resistant and would ensure no heat transfer from the legs to the elevated surface where you are cooking. It’s heavy so you’ll want to size it to meet your needs with no excess.
Here’s a 20” x 17” metal trivet mat that might work:
Go to a home depot and buy a 30”x30” ceramic floor tile. Probably 5$.
2-4 square concrete stepping “stones” from the landscape section at Home Depot or Lowe’s might be an idea. Or some 1’ tiles from the tile section.
I got tired of cooking on the ground with my Dutch Ovens so I bought this...
I can put the charcoal right on the table and bake to my heart’s content.
I’d go with one I didn’t care about. Just sain.
We’ve used a small charcoal grill camping, and bought a nice folding aluminum camp table.
It works great and is fire resistant.
I used to put my small charcoal grill on a wood picnic table with a layer of tin foil under the grill.
How about a large AirBake cookie sheet on a few bricks or thin pavers (on the campsite table)? They’re cheap and lightweight. 16x14” and 20x15.5”.