On this house, we installed a board-on-board siding in a random pattern. The material that we are using here is a Thermally Modified Poplar. The thermal modification process heats the wood to near-burning temperatures, causing changes in the chemical structure of the wood. These changes render the wood more dimensionally stable (less prone to warping) and give it insect and rot resistance similar to that of a pressure treated wood. The treatment process causes the wood to turn a deep brown color, similar to Walnut.
In this application, we will leave the poplar with the natural finish, which will fade to grey over the next couple of years. It is possible to maintain the dark color of the wood by sealing it before installation.
This product opens up varieties of wood for exterior uses that have not historically held up well, and it does this without the use of any chemical treatment.