best wood for loft hatch in bathroom

[akaydnc]

Hi, I intend to install a drop down hinged loft hatch in bathroom. Current one is far too heavy and does not close.
What would be the best wood to use ?
As there will be moisture, do not want to fit something that will warp later on. Thankyou.

 

[foxhole]

Plastic

https://www.screwfix.com/p/manthorpe-gl250-insulated-drop-down-loft-access-door-white-686mm-x-856mm/67659?ref=SFAppShare