Many people ask us what the recommended age limit for this bed, and there really is no age limit it is more of a weight limit. All kids are different and they grow up at different speeds, it is really up to you and the child to determine when they are comfortable climbing a ladder or stairs to use the upper beds. As for Adult and Teen use let us first explain how bunk beds are tested and rated. In order for a bed to be meet ASTM safety standard they have to be 3rd party tested and the top beds have to be able to support 400lbs for at least 5 minutes before the the structure fails. How this is done is simple, the testing company assembles the bed just like you would, weighs and adds the mattress and then slowly spreads weight evenly across the entire top bed area until they reach 400lbs if the bed fails before that it does not pass and cannot be sold legally in the US.
The 400lb distributed weight rating is the testing weight rating, this is not jumping up and down weight. The Discovery World Furniture are plenty strong but do not think that you can put a 400lb person on the top bunk, as there would be no way for them to get to the lay down position without focusing a lot of weight onto 1 or 2 slats at a time. If you have jumpy kids or larger teens or adults that will be using the bed then we recommend you purchase the Metal Center Support Slats. The metal center supports help to spread the weight out across the slats and adds 2 other support points of contact, one on the headboard and one on the footboard. The intent of the steel support bar is to keep individual slats from failing when pressure is focused on a small area rather than increasing the weight limit by a specific amount.
Our recommendation for the top bed max weight would be around 200lbs or up to 250lbs with the metal center supports. We do sell these beds to youth camps, colleges, firehouses, and mens and women's shelter and have had very few calls about beds breaking from normal use. If you are planning on using these bed in a commercial applications like rental properties, we strongly recommend buying the metal center supports.