There is not exact distance. Dow recommends to place them slightly under the roof edge where if the water dripped off the roof, it would not drip on them. In most cases this is 2-3 feet from the foundation wall. Termite bait stations can be placed anywhere, there is no exact science. It's like going fishing, sometimes you just drop the hook in the water and you catch fish without any real effort. Other times you can't catch anything when you have tried all the latest gadgets. My advice is to put the stations under the roof edge and approximately every 10 feet or less. Check them every 3 months and insert the Shatter bait when you see live termites feeding. That's as simple as it gets.