A slightly controversial material is Plywood, and here I’m adding to the controversy by using 12mm thick Ply (*for testing purposes only – I’m not recommending it).
This article might show how the material lasts and also generally I’d like to see how well, or poorly a 12mm thick box works for temperatures in comparison with other boxes.
Marine Ply is hardwood and used for many things like boat construction where it’s covered over with fibreglass, but it isn’t magic and can still rot. Some people use it for making native bee boxes and I have seen many plywood boxes that have lasted twenty years. It may just depend on the exposure to external moisture.
Photos: Boxes complete and painted white.
Below: Temperature probes installed and I’ll get bees in towards the end of the year – 2023.
Test results will appear in the Test Category here: https://www.nativebeehives.com/category/tests/