We are ready to order wood to start building our house but I would like recomendations on what type of wood to use. We are building an underground home. (The wood will not come in contact with dirt.) We will be using 6" x 6" posts and 6" x 8" girders. I was planning on using untreated pine but one guy at a lumber place said douglas fir would be better(and more expensive!) Is pine going to crack and check badly like he said or is he trying to make money on us? We looked into cedar too. Its less expensive that the fir! What do Y'all think?