Raised bed drainage

[Essexboy]

Considering building a raised bed from a kit which includes a liner. To drain off excess moisture do I simply puncture the base of the liner or leave it intact ?
any advice would be greatly appreciated.

[Penellype]

Is the liner waterproof? Maybe assemble the bed and put the liner in it and add some water then wait and see if it drains. If it doesn't I would be inclined to puncture it, otherwise if there is a deluge you will end up with a muddy pond.

[rary]

If it's a kit I would think it should let water through, but I would follow Penellypes advice just to be on the safe side