Just shows how well hidden the screws are.
They are about 2 1/2" to 3" long, they go into pieces at right angles, the width of the "Au vent" (2m) at 50mm centres, which themselves are screwed into other pieces running the length of it all and they themselves are screwed to the concrete/brick support!
Twas quite a lot of work, but it raised the level until it was much easier to step out of the "French windows" or "porte fenetres " as they laughingly call them. So Wifey with her paralysed foot is less likely to trip or fall with a drink in her hand. Also all the decking has to be perfectly level with no protruding bits. Which of course is normal,
Just found one Wifey took of the last one about to go down, you'll see some of the really p!ssed ones in the back ground and pbvs I saved one of the straightest for the last, (still not straight!) as I couldn't use my special but bulky tool I had been using to un warp the boards that were warped, and hold them in place while screwing them down!
Lesson learned, NEVER buy decking, or
any other wood, then keep it for any length of time before using it, even if you keep it dry!
@kevstar already knows this of course!