Hey Doug - you would likely benefit from purchasing additional EAP-225 outdoor units and placing them in areas where you're not currently getting sufficient Wifi coverage. The EAP225's support mesh and wireless roaming, so as long as one EAP225 is in range of another, it can "mesh" with your existing EAP225 and spread that signal into other areas of your property or residence.
If you want an enterprise-level solution to expanding wifi coverage, the best bet is to run a patch data cable (cat5e/6) from the access points (EAP225's) directly back to the main router. This isn't always possible because running wires can involve a lot of work/modification to structures or outdoor areas, but it's the best way to achieve strong/wide wifi coverage in a larger area. Otherwise, the EAP225's have decent range for wireless mesh. Keep in mind that the farther they are from each other, the less reliable they'll be for spreading your signal out to longer distances.