Hauling drums of hazmat on flatbed......

Your truck, your rules. If they don't like that they can find someone else to haul their freight.

 

I rather have the old carboys (Big portable tanks of fluid...) inside the van. The whole thing would act like a tanker but I preferred van to flat with carboys. Although I can see the speedy unload possible with flat.

 

Keep it short, like 4 inches. I see some guys using these v boards with too much strap and they don't sit close enough to the corner to be effective.

 

I'm not gonna put words in your mouth, but I think you mean 4" in between the boards, right? 4" total wouldn't be enough to even screw into the boards.....
I'd say 12" total - 4" for each board to screw into, and 4" in the middle.

 

That's exactly what I meant. Sorry I phrased that badly.

 

It's all good. I just didn't want the OP sitting there, scratching his head and going WTF?!?

 

That is about what it should be. Usually 6 inches overall 4 inches between boards. You have literally paraphrasing miles of strapping to use. Chop em up and build the boards.

After you use the boards a while, keep a eye running over the little straps now and then. One or two will start to fray after a board set is stressed so be prepared for either rebuilding or building a new set. Used to use them all the time with shingles and roofing rolls.

 

I say 10" straps. I found 4" gap to be too wide. On stuff like stone I found the larger gap allowed the strap to still contact the stone, maybe if you used 2x4s as the board it might be ok.