We only use Western Redwood Cedar. We do not use pressure treated pine. Treated wood is usually very heavy when its installed due to the chemicals that have been pressured into the wood to make it resistant to rot, insects and decay. Shortly after its exposed to the elements, it dries out and begins to twist, warp, curl and split. Western Redwood Cedar is naturally resistant to rot, insects and decay, therefore does not need to be treated. Cedar also has a better appearance.