connecting 2 routers or more without wds

Hi Guys, I’m looking to extend a wireless network to increase the coverage over a property. neither router has WDS and I wondered if I could add the second router to the same network as the first providing i use the same range and subnet mask? Or is there another/better way of doing it? ( I have thought of using high gain antenna but the routers have fixed antenna. ) any help appreciated.
many thanks in advance..
glenn