Fence top trellis holding water = rot?

[Skyhigh]

Hey,

We've bought some trellis to soften up the top of the harsh 6ft fence and put some climbers on too.

I noticed that the bottom of the trellis has a channel. There's no drainage so I'd assume this means it'll collect sitting water and promote (eventual) rot?

Is this nothing to worry about? Should I simply add drainage holes? Or even fill it in? (ideally not with 11x 6ft panels to go up!)

 

[Robbox]

If it's pressure treated and not in contact with soil, then it should last the usual 15 years that pressure treated timber is given.

 

[Nige F]

It wouldn't hurt to put clear wood treatment in the channel then the end grain of the trellis will soak it up.

 

[big-all]

timber will only rot at around a constant 19% moisture content hence why sheds and fence posts rot round the back or at ground level because thats where its held at the correct level for weeks on end