My last shop had a 12 foot cantilevered bench out 24 inches. Just 2x4s angled up from the wall footer (no sheeting or insulation) and a 2x4 frame with chipboard on top. Beat the **** out of stuff and tossed Pontiac big block heads around on them for years. Never wiggled.
Current one has some big built-ins that come out 3 feet. Way too much space taken up. Going to tear them out and put in some cantilevered ones.
That's how mine currently are in the garage. What i like about it is the fact that I can keep things swept up or blown out with the leafblower without things getting underneath of a bench. I've built three different types since I built my garage. The one with the most storage of course the bench that was 33" deep with doors on the front. I had it down one wall and it was maybe 20' long. I also had overheads to match. I built it with a toekick so nothing would get underneath. The bad thing was though that it would wick up a little water if I washed the garage out. I ended up giving it all to a friend of mine for his garage as he didn't have one cabinet in there.
My second set was two 8' long benches, 36" deep, with one shelf underneath. I had one on each side of the window in the garage and it gave me 16' of storage. I was never really satisfied with that style though.
The third and probably last is what I have now. I got in on the Gladiator deal a couple of years ago, and have 18 of the Gladiator overheads. Then I now have the cantilevered lower bench. On one side wall, the bench is 24' long, then on the front wall i have a 5' long bench that site a little higher and deeper than the sidewall bench. This is where the computer, catalogs, printer and such is at. I also picked up a 2' deep x 6' long office desk at the ReStore for $20. Not quite sure how I am going to utilize it though, and not real pleased with it. I plan on moving my mill and lathe over to the other side of the garage to open up some space on what was the large side of the garage before I tore the wall out dividing the garage. I want to add a 6' x 24' bumpout on the side of the garage, but that won't happen until probably next year.. Once I add the bumpout, then my three roller boxes will go into that area, and open up some more floorspace. I'd also like to do away with our outside shed, then add on to the back of the garage with maybe a 16' x 24' addition for cold storage and keep the tractors, snowblowers and all of the garden tools in there. I'll just have to see what next year brings on that.
But as far as benches, I have been very pleased with the cantilevered style. It's strong, it's easy to clean around now, and I don't have as many spiders, or so it seems, because they don't have as many places to hide. And I like the fact that I can scrub out the garage now with soap and water and don't have to worry about water wicking up on any wood.
