So more of a raised bed than a planter - what sort of material did he construct them from? Treated or untreated wood?

yes I suppose more like a raised bed, its wood which I was planing on painting

Whether you need membrane in the bottom is down to what you want to grow in them - you can certainly grow much bigger plants if you leave them open at the bottom because they'll be able to root into the ground beneath. If they're quite shallow, then I'd leave them open, but fork over the soil at the base a bit to improve drainage. Leave them open if you want to grow an ornamental shrub or larger decorative plant too. You don't need gravel on top of the membrane if you choose to use it. If the wood's not pressure treated, then painting it will help it to last longer, but it will rot through eventually because of contact with damp soil.

Forget the weed fabric; it doesn't work, it looks ugly, it's a royal pain in the tucas, waste of money & creates a barrier to our friends, the earthworms - nature's tillers of the land.

The vast majority of weed seeds merely need to lay on the surface to germinate and wreak their havoc. You'll still have to get those nasty weeds out while that fabric is somewhere down there serving no purpose at all. The roots will penetrate that fabric anyway.

Till the ground at the base of the planters. Add some good organic compost, no gravel. Just build it up with good dark organic compost about an inch below the rim. Now you'll have an environment for happy plants. They can throw down roots far and wide with no barriers & the earthworms will be pleased as punch.

Once you add your lovely plants, you can top off that last inch with an attractive mulch; pea gravel, slate chips, wood chips, what ever you like. That will be your weed barrier. As the earth in the planters settles, just keep topping off with more compost. Hope this helps - good luck.

thanks guys, planters are now done! they look fab, ill get a photo and post it, onto the next task....