boards as garden bed border?

I have a stack of pine boards that are partly rotten.  I need to outline garden beds and am thinking about laying board down flat to outline the beds plus that would suppress weeds around the beds? Or is that asking for snails and other trouble?  

I inherited a veggie plot where each bed was marked out with boards. It was fine for a few years, but quickly became a nightmare. As the boards started rotting the weeds moved in, and rooted directly into the board. After that they were impossible to shift. To make maters worse, when the beds were built they were sized so that it was impossible to get the mower down between rows, so there was an endless job of either strimming or hands and knees trimming with sheers.

Regarding slugs and snails, yes I certainly found that they liked hanging out by the boards, but I couldn't say if it increased the total slug population.

These days my preference is a little different. I now don't have beds as such, I have larger areas where I can plant rows of crops. The rows are in slightly different places each year, rather than fixed by the spacings of the beds. I have used, to good effect, pieces of old board laid down flat between rows, as temporary walkways. I cut them short enough that they are easy to move, and simply lift them periodically to weed a what-not. Incidentally, they make good slug traps like this, as the slugs collect under the boards where they can quickly be collected or exposed to chickens if you have them.

Thank you.  I might give the boards a try in one area.  My kids decided to build more frames around  other beds.  Thank you.  

Like Michael said, it is painful because you can't get rid of the grass. If you build a raised bed you do it for a reason, be it drainage or you can't bend down.