Plywood covering to timber garage door

[wbmkk]

The lower timbers on my garage door are a bit worn, so I think I could cover it with a small section of plywood, perhaps 600mm wide.

As it is an up an over door I don't want to add much weight, so would 3.6mm thick plywood be OK ? or should i opt for 6mm ply.

Would MDF do ? or is this no good for outside (even after painting)

I rarely open the door and as it's out of sight, so I think the part covering and a repaint will do in the meantime.

I realise a new door would be the best option, but it's actually a double width door, so a whole new one will be a bit too expensive for me at this time.

Any advice would be helpful

 

[big-all]

not mdf
6mm ply a 2 year extention or there abouts
sheet plastic 1-3mm about 5 years assuming the structure off the door holds together

http://www.directplasticsonline.co.uk/