© As long as a bee hive provides protection from the wind and wet, it does not matter much to the bees what material is used in its construction so this is largely a choice of the bee hive maker but ultimately of the beekeeper.
Light weight or low density timber is preferable not only for the ease of use for the beekeeper but also, more importantly, because it has lower thermal conductivity providing better insulation for the bees. Heavy or dense timber or board should therefore be avoided as should any dipped or pressure treated timber. The persistence of plastics and polystyrene foam and their adverse effects on nature and the environment are well known - just one reason why we also avoid plastic or polstyrene bee hives.
No matter what material is used in construction, bee hives must be kept off the ground and the exterior surfaces must have a water repellent treatment. A wet bee hive is a severe disadvantage to the bees, they will use their energy to dry it out - stand outside in wet clothes and you will quickly understand the adverse effect.
Concrete slabs or blocks and hive stands can be used to keep the bee hive off the ground and also bring the hive to a more convenient working height.
There are many ways of weather proofing or protecting the timber according to your taste, from natural waxes and oils to synthetic paints and stains. Only apply product to the exterior surfaces of the bee hive (the bees take care of the interior) and allow plenty of time for the hive to dry and air out before populating.
Timber beehives correctly treated and maintained should last years although we have hives in our apiaries that are decades old.