Loft ladders are generally available in wood. However care should be taken when choosing a model.
Wooden loft ladders are more suitable for occasional use. If your loft ladders are used regularly or are for use in a commercial environment, look towards a more heavy duty metal loft ladder. All loft ladders nowadays generally come complete with the ladder, ceiling hole lining, trap door and most importantly a spring balanced action.
This spring balanced action makes the ladder easier to use and also acts as a safety feature if the trap door is opened, perhaps by a child or elderly person.
Heavy duty loft ladders are generally made as a 3 or 4 part folding ladder with handrails both sides or in a pantograph concertina style. The pantograph style is usually used for smaller ceiling hole sizes.
For commercial use it is possible to have the trapdoor fixed at a suspended ceiling level and then by means of a framework allow access through the ceiling void to the upper floor.