Eureka With NON-Bathtub Type Floor (Question)

I live 3 miles from the Eureka Tent factory, go to a lot of garage sales, so naturally have aquired several very nice vintage Eureka tents in great condition. I have set each tent up and noticed that none of them have a tarp material floor like my other (newer) tents. The floor material of these Eureka's looks like the same material that the walls of the tent are made of. Is this style floor completely waterproof witout some type of water seal application? The material seams kind of thin....I would like to use these tents at some point. Thanks