Hello Everybody!

Username chosen in honor of my British origins and a rather infamous fire there in 1666. :)

Anyway, I'm halfway through building my first outdoor kitchen and have a few questions if I may. I'm an engineer with 30 years in the offshore oil and gas industry, more used to building oil platforms and pipelines than outdoor kitchens, and my father is a retired industrial HVAC engineer, so I'm more than equipped enough to make this a DIY job generally. I also live in an unincorporated area of Harris County Texas, so no pesky city permits to worry about.

The grill we have bought is a Solaire 30 inch natural gas infrared model with the rotisserie and back burner. It arrives, hopefully, in about a week.

All of the services (gas pipe, water pipes, drain and electricity) were put in when we had the house built a little under 5 years ago, so no need to worry about those.

The grill is going to sit on concrete blocks inside a stucco-covered concrete block structure. No wood or other combustible materials involved and I'm keeping the plastic pipes, electrical cables, etc. well away from the grill. The sides and back of the grill enclosure will be fully blocked in. The front will have stainless steel cabinet doors under the grill. Any gap will be filled in with cement or cement board, as there's not enough room for a proper lintel here. The countertop will be granite or marble or some other real "rock". The Memsahib wanted SileStone or some other artificial stuff but I'm pushing back because it'll simply get cooked in our Summer temperatures and sunlight.

Q1 - Do I need to put vents behind the grill to supply combustion air? There won't be a fridge in the same space, just the grill, otherwise enclosed on all four sides except for the air intakes which I believe are under the protruding front panel? I've got the vents (two 14-inch long x 5 inch high, stainless steel). Not sure if I need none, one or two. None or one and I don't need a lintel. Two and I do.

Q2 - Can I get away with supporting it just on the two short sides? It'll sit on concrete ledges about 3 inches wide down either short side. I can support it across most of the back as well if needed. I can't support the front as there's going to be a cabinet door underneath and there's not enough height to put a lintel in between.

Q3 - Do I need to use fire bricks or fire cement anywhere?

Q4 - Do I need to ensure an air gap around the sides and back between the grill casing and the blockwork? If so is about 1 inch minimum enough?

Q5 - What's the recommended maximum unsupported span for granite or marble countertops? I'm planning on 1-inch thick material. I can put cement backer boards on top the blockwork but not plywood, as it'll rot and / or catch fire. Maximum span I have at the moment is the fridge slot, 26 inches x 26 inches square, supported round the sides and back, but not at the front where the fridge will slide in.
 
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